try setting to weak instead of deinit

.github/actions/install/action.yml

@@ -5,7 +5,7 @@ inputs:
   zig:
     description: 'Zig version to install'
     required: false
-    default: '0.15.2'
+    default: '0.15.1'
   arch:
     description: 'CPU arch used to select the v8 lib'
     required: false
@@ -17,7 +17,7 @@ inputs:
   zig-v8:
     description: 'zig v8 version to install'
     required: false
-    default: 'v0.1.33'
+    default: 'v0.1.30'
   v8:
     description: 'v8 version to install'
     required: false

.github/workflows/wpt.yml

@@ -31,7 +31,7 @@ jobs:
       - uses: ./.github/actions/install
 
       - name: json output
-        run: zig build wpt -- --json > wpt.json
+        run: zig build -Doptimize=ReleaseFast wpt -- --json > wpt.json
 
       - name: write commit
         run: |

.github/workflows/zig-fmt.yml

@@ -1,7 +1,7 @@
 name: zig-fmt
 
 env:
-  ZIG_VERSION: 0.15.2
+  ZIG_VERSION: 0.15.1
 
 on:
   pull_request:

.gitmodules

@@ -31,6 +31,3 @@
 [submodule "vendor/curl"]
 	path = vendor/curl
 	url = https://github.com/curl/curl.git
-[submodule "vendor/brotli"]
-	path = vendor/brotli
-	url = https://github.com/google/brotli

Dockerfile

@@ -1,10 +1,10 @@
 FROM debian:stable
 
 ARG MINISIG=0.12
-ARG ZIG=0.15.2
+ARG ZIG=0.15.1
 ARG ZIG_MINISIG=RWSGOq2NVecA2UPNdBUZykf1CCb147pkmdtYxgb3Ti+JO/wCYvhbAb/U
 ARG V8=14.0.365.4
-ARG ZIG_V8=v0.1.33
+ARG ZIG_V8=v0.1.30
 ARG TARGETPLATFORM
 
 RUN apt-get update -yq && \

Makefile

@@ -96,16 +96,9 @@ wpt-summary:
 	@printf "\e[36mBuilding wpt...\e[0m\n"
 	@$(ZIG) build wpt -- --summary $(filter-out $@,$(MAKECMDGOALS)) || (printf "\e[33mBuild ERROR\e[0m\n"; exit 1;)
 
-## Test - `grep` is used to filter out the huge compile command on build
-ifeq ($(OS), macos)
+## Test
 test:
-	@script -q /dev/null sh -c 'TEST_FILTER="${F}" $(ZIG) build test -freference-trace --summary all' 2>&1 \
-		| grep --line-buffered -v "^/.*zig test -freference-trace"
-else
-test:
-	@script -qec 'TEST_FILTER="${F}" $(ZIG) build test -freference-trace --summary all' /dev/null 2>&1 \
-		| grep --line-buffered -v "^/.*zig test -freference-trace"
-endif
+	@TEST_FILTER='${F}' $(ZIG) build test -freference-trace --summary all
 
 ## Run demo/runner end to end tests
 end2end:

README.md

@@ -164,7 +164,7 @@ You can also follow the progress of our Javascript support in our dedicated [zig
 
 ### Prerequisites
 
-Lightpanda is written with [Zig](https://ziglang.org/) `0.15.2`. You have to
+Lightpanda is written with [Zig](https://ziglang.org/) `0.15.1`. You have to
 install it with the right version in order to build the project.
 
 Lightpanda also depends on

build.zig

@@ -23,7 +23,7 @@ const Build = std.Build;
 
 /// Do not rename this constant. It is scanned by some scripts to determine
 /// which zig version to install.
-const recommended_zig_version = "0.15.2";
+const recommended_zig_version = "0.15.1";
 
 pub fn build(b: *Build) !void {
     switch (comptime builtin.zig_version.order(std.SemanticVersion.parse(recommended_zig_version) catch unreachable)) {
@@ -245,7 +245,6 @@ fn addDependencies(b: *Build, mod: *Build.Module, opts: *Build.Step.Options) !vo
             mod.addCMacro("HAVE_ASSERT_H", "1");
             mod.addCMacro("HAVE_BASENAME", "1");
             mod.addCMacro("HAVE_BOOL_T", "1");
-            mod.addCMacro("HAVE_BROTLI", "1");
             mod.addCMacro("HAVE_BUILTIN_AVAILABLE", "1");
             mod.addCMacro("HAVE_CLOCK_GETTIME_MONOTONIC", "1");
             mod.addCMacro("HAVE_DLFCN_H", "1");
@@ -380,7 +379,6 @@ fn addDependencies(b: *Build, mod: *Build.Module, opts: *Build.Step.Options) !vo
         }
 
         try buildZlib(b, mod);
-        try buildBrotli(b, mod);
         try buildMbedtls(b, mod);
         try buildNghttp2(b, mod);
         try buildCurl(b, mod);
@@ -486,30 +484,6 @@ fn buildZlib(b: *Build, m: *Build.Module) !void {
     } });
 }
 
-fn buildBrotli(b: *Build, m: *Build.Module) !void {
-    const brotli = b.addLibrary(.{
-        .name = "brotli",
-        .root_module = m,
-    });
-
-    const root = "vendor/brotli/c/";
-    brotli.addIncludePath(b.path(root ++ "include"));
-    brotli.addCSourceFiles(.{ .flags = &.{}, .files = &.{
-        root ++ "common/constants.c",
-        root ++ "common/context.c",
-        root ++ "common/dictionary.c",
-        root ++ "common/platform.c",
-        root ++ "common/shared_dictionary.c",
-        root ++ "common/transform.c",
-        root ++ "dec/bit_reader.c",
-        root ++ "dec/decode.c",
-        root ++ "dec/huffman.c",
-        root ++ "dec/prefix.c",
-        root ++ "dec/state.c",
-        root ++ "dec/static_init.c",
-    } });
-}
-
 fn buildMbedtls(b: *Build, m: *Build.Module) !void {
     const mbedtls = b.addLibrary(.{
         .name = "mbedtls",

build.zig.zon

@@ -5,9 +5,9 @@
     .fingerprint = 0xda130f3af836cea0,
     .dependencies = .{
         .v8 = .{
-            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/305bb3706716d32d59b2ffa674731556caa1002b.tar.gz",
-            .hash = "v8-0.0.0-xddH63bVAwBSEobaUok9J0er1FqsvEujCDDVy6ItqKQ5",
+            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/7177ee1ae267a44751a0e7e012e257177699a375.tar.gz",
+            .hash = "v8-0.0.0-xddH63TCAwC1D1hEiOtbEnLBbtz9ZPHrdiGWLcBcYQB7",
         },
-        //.v8 = .{ .path = "../zig-v8-fork" }
+        // .v8 = .{ .path = "../zig-v8-fork" }
     },
 }

flake.lock

@@ -75,11 +75,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1760968520,
-        "narHash": "sha256-EjGslHDzCBKOVr+dnDB1CAD7wiQSHfUt3suOpFj9O1Q=",
+        "lastModified": 1756822655,
+        "narHash": "sha256-xQAk8xLy7srAkR5NMZFsQFioL02iTHuuEIs3ohGpgdk=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "e755547441a0413942a37692f7bf7fc6315bb7f6",
+        "rev": "4bdac60bfe32c41103ae500ddf894c258291dd61",
         "type": "github"
       },
       "original": {
@@ -136,11 +136,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1760747435,
-        "narHash": "sha256-wNB/W3x+or4mdNxFPNOH5/WFckNpKgFRZk7OnOsLtm0=",
+        "lastModified": 1756555914,
+        "narHash": "sha256-7yoSPIVEuL+3Wzf6e7NHuW3zmruHizRrYhGerjRHTLI=",
         "owner": "mitchellh",
         "repo": "zig-overlay",
-        "rev": "d0f239b887b1ac736c0f3dde91bf5bf2ecf3a420",
+        "rev": "d0df3a2fd0f11134409d6d5ea0e510e5e477f7d6",
         "type": "github"
       },
       "original": {

flake.nix

@@ -49,7 +49,7 @@
           targetPkgs =
             pkgs: with pkgs; [
               # Build Tools
-              zigpkgs."0.15.2"
+              zigpkgs."0.15.1"
               zls
               python3
               pkg-config

src/app.zig

@@ -4,7 +4,7 @@ const Allocator = std.mem.Allocator;
 
 const log = @import("log.zig");
 const Http = @import("http/Http.zig");
-const Platform = @import("browser/js/Platform.zig");
+const Platform = @import("runtime/js.zig").Platform;
 
 const Telemetry = @import("telemetry/telemetry.zig").Telemetry;
 const Notification = @import("notification.zig").Notification;
@@ -36,7 +36,6 @@ pub const App = struct {
         http_connect_timeout_ms: ?u31 = null,
         http_max_host_open: ?u8 = null,
         http_max_concurrent: ?u8 = null,
-        user_agent: [:0]const u8,
     };
 
     pub fn init(allocator: Allocator, config: Config) !*App {
@@ -54,7 +53,6 @@ pub const App = struct {
             .http_proxy = config.http_proxy,
             .tls_verify_host = config.tls_verify_host,
             .proxy_bearer_token = config.proxy_bearer_token,
-            .user_agent = config.user_agent,
         });
         errdefer http.deinit();
 

src/browser/Scheduler.zig

@@ -17,6 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const log = @import("../log.zig");
 const Allocator = std.mem.Allocator;
 
 const Scheduler = @This();
@@ -37,10 +38,8 @@ pub fn init(allocator: Allocator) Scheduler {
 }
 
 pub fn reset(self: *Scheduler) void {
-    // Our allocator is the page arena, it's been reset. We cannot use
-    // clearAndRetainCapacity, since that space is no longer ours
-    self.high_priority.clearAndFree();
-    self.low_priority.clearAndFree();
+    self.high_priority.clearRetainingCapacity();
+    self.low_priority.clearRetainingCapacity();
 }
 
 const AddOpts = struct {

src/browser/ScriptManager.zig

@@ -18,10 +18,10 @@
 
 const std = @import("std");
 
-const js = @import("js/js.zig");
 const log = @import("../log.zig");
 const parser = @import("netsurf.zig");
 
+const Env = @import("env.zig").Env;
 const Page = @import("page.zig").Page;
 const DataURI = @import("DataURI.zig");
 const Http = @import("../http/Http.zig");
@@ -38,6 +38,9 @@ page: *Page,
 // used to prevent recursive evalutaion
 is_evaluating: bool,
 
+// used to prevent executing scripts while we're doing a blocking load
+is_blocking: bool = false,
+
 // Only once this is true can deferred scripts be run
 static_scripts_done: bool,
 
@@ -45,6 +48,12 @@ static_scripts_done: bool,
 // on shutdown/abort, we need to cleanup any pending ones.
 asyncs: OrderList,
 
+// When an async script is ready to be evaluated, it's moved from asyncs to
+// this list. You might think we can evaluate an async script as soon as it's
+// done, but we can only evaluate scripts when `is_blocking == false`. So this
+// becomes a list of scripts to execute on the next evaluate().
+asyncs_ready: OrderList,
+
 // Normal scripts (non-deferred & non-async). These must be executed in order
 scripts: OrderList,
 
@@ -58,22 +67,6 @@ client: *Http.Client,
 allocator: Allocator,
 buffer_pool: BufferPool,
 script_pool: std.heap.MemoryPool(PendingScript),
-sync_module_pool: std.heap.MemoryPool(SyncModule),
-async_module_pool: std.heap.MemoryPool(AsyncModule),
-
-// We can download multiple sync modules in parallel, but we want to process
-// then in order. We can't use an OrderList, like the other script types,
-// because the order we load them might not be the order we want to process
-// them in (I'm not sure this is true, but as far as I can tell, v8 doesn't
-// make any guarantees about the list of sub-module dependencies it gives us
-// So this is more like a cache. When a SyncModule is complete, it's put here
-// and can be requested as needed.
-sync_modules: std.StringHashMapUnmanaged(*SyncModule),
-
-// Mapping between module specifier and resolution.
-// see https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/script/type/importmap
-// importmap contains resolved urls.
-importmap: std.StringHashMapUnmanaged([:0]const u8),
 
 const OrderList = std.DoublyLinkedList;
 
@@ -85,51 +78,27 @@ pub fn init(browser: *Browser, page: *Page) ScriptManager {
         .asyncs = .{},
         .scripts = .{},
         .deferreds = .{},
-        .importmap = .empty,
-        .sync_modules = .empty,
+        .asyncs_ready = .{},
         .is_evaluating = false,
         .allocator = allocator,
         .client = browser.http_client,
         .static_scripts_done = false,
         .buffer_pool = BufferPool.init(allocator, 5),
         .script_pool = std.heap.MemoryPool(PendingScript).init(allocator),
-        .sync_module_pool = std.heap.MemoryPool(SyncModule).init(allocator),
-        .async_module_pool = std.heap.MemoryPool(AsyncModule).init(allocator),
     };
 }
 
 pub fn deinit(self: *ScriptManager) void {
     self.reset();
-    var it = self.sync_modules.valueIterator();
-    while (it.next()) |value_ptr| {
-        value_ptr.*.buffer.deinit(self.allocator);
-        self.sync_module_pool.destroy(value_ptr.*);
-    }
-
     self.buffer_pool.deinit();
     self.script_pool.deinit();
-    self.sync_module_pool.deinit();
-    self.async_module_pool.deinit();
-
-    self.sync_modules.deinit(self.allocator);
-    // we don't deinit self.importmap b/c we use the page's arena for its
-    // allocations.
 }
 
 pub fn reset(self: *ScriptManager) void {
-    var it = self.sync_modules.valueIterator();
-    while (it.next()) |value_ptr| {
-        value_ptr.*.buffer.deinit(self.allocator);
-        self.sync_module_pool.destroy(value_ptr.*);
-    }
-    self.sync_modules.clearRetainingCapacity();
-    // Our allocator is the page arena, it's been reset. We cannot use
-    // clearAndRetainCapacity, since that space is no longer ours
-    self.importmap = .empty;
-
     self.clearList(&self.asyncs);
     self.clearList(&self.scripts);
     self.clearList(&self.deferreds);
+    self.clearList(&self.asyncs_ready);
     self.static_scripts_done = false;
 }
 
@@ -142,7 +111,7 @@ fn clearList(_: *const ScriptManager, list: *OrderList) void {
     std.debug.assert(list.first == null);
 }
 
-pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime ctx: []const u8) !void {
+pub fn addFromElement(self: *ScriptManager, element: *parser.Element) !void {
     if (try parser.elementGetAttribute(element, "nomodule") != null) {
         // these scripts should only be loaded if we don't support modules
         // but since we do support modules, we can just skip them.
@@ -175,9 +144,6 @@ pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime c
         if (std.ascii.eqlIgnoreCase(script_type, "module")) {
             break :blk .module;
         }
-        if (std.ascii.eqlIgnoreCase(script_type, "importmap")) {
-            break :blk .importmap;
-        }
 
         // "type" could be anything, but only the above are ones we need to process.
         // Common other ones are application/json, application/ld+json, text/template
@@ -191,12 +157,11 @@ pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime c
     if (try parser.elementGetAttribute(element, "src")) |src| {
         if (try DataURI.parse(page.arena, src)) |data_uri| {
             source = .{ .@"inline" = data_uri };
-        } else {
-            remote_url = try URL.stitch(page.arena, src, page.url.raw, .{ .null_terminated = true });
-            source = .{ .remote = .{} };
         }
+        remote_url = try URL.stitch(page.arena, src, page.url.raw, .{ .null_terminated = true });
+        source = .{ .remote = .{} };
     } else {
-        const inline_source = parser.nodeTextContent(@ptrCast(element)) orelse return;
+        const inline_source = try parser.nodeTextContent(@ptrCast(element)) orelse return;
         source = .{ .@"inline" = inline_source };
     }
 
@@ -212,7 +177,7 @@ pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime c
     if (source == .@"inline" and self.scripts.first == null) {
         // inline script with no pending scripts, execute it immediately.
         // (if there is a pending script, then we cannot execute this immediately
-        // as it needs to be executed in order)
+        // as it needs to best executed in order)
         return script.eval(page);
     }
 
@@ -233,18 +198,14 @@ pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime c
         self.scripts.append(&pending_script.node);
         return;
     } else {
-        log.debug(.http, "script queue", .{
-            .ctx = ctx,
-            .url = remote_url.?,
-            .stack = page.js.stackTrace() catch "???",
-        });
+        log.debug(.http, "script queue", .{ .url = remote_url.? });
     }
 
     pending_script.getList().append(&pending_script.node);
 
     errdefer pending_script.deinit();
 
-    var headers = try self.client.newHeaders();
+    var headers = try Http.Headers.init();
     try page.requestCookie(.{}).headersForRequest(page.arena, remote_url.?, &headers);
 
     try self.client.request(.{
@@ -262,144 +223,88 @@ pub fn addFromElement(self: *ScriptManager, element: *parser.Element, comptime c
     });
 }
 
-// Resolve a module specifier to an valid URL.
-pub fn resolveSpecifier(self: *ScriptManager, arena: Allocator, specifier: []const u8, base: []const u8) ![:0]const u8 {
-    // If the specifier is mapped in the importmap, return the pre-resolved value.
-    if (self.importmap.get(specifier)) |s| {
-        return s;
+// @TODO: Improving this would have the simplest biggest performance improvement
+// for most sites.
+//
+// For JS imports (both static and dynamic), we currently block to get the
+// result (the content of the file).
+//
+// For static imports, this is necessary, since v8 is expecting the compiled module
+// as part of the function return. (we should try to pre-load the JavaScript
+// source via module.GetModuleRequests(), but that's for a later time).
+//
+// For dynamic dynamic imports, this is not strictly necessary since the v8
+// call returns a Promise; we could make this a normal get call, associated with
+// the promise, and when done, resolve the promise.
+//
+// In both cases, for now at least, we just issue a "blocking" request. We block
+// by ticking the http client until the script is complete.
+//
+// This uses the client.blockingRequest call which has a dedicated handle for
+// these blocking requests. Because they are blocking, we're guaranteed to have
+// only 1 at a time, thus the 1 reserved handle.
+//
+// You almost don't need the http client's blocking handle. In most cases, you
+// should always have 1 free handle whenever you get here, because we always
+// release the handle before executing the doneCallback. So, if a module does:
+//    import * as x from 'blah'
+// And we need to load 'blah', there should always be 1 free handle - the handle
+// of the http GET we just completed before executing the module.
+// The exception to this, and the reason we need a special blocking handle, is
+// for inline modules within the HTML page itself:
+//    <script type=module>import ....</script>
+// Unlike external modules which can only ever be executed after releasing an
+// http handle, these are executed without there necessarily being a free handle.
+// Thus, Http/Client.zig maintains a dedicated handle for these calls.
+pub fn blockingGet(self: *ScriptManager, url: [:0]const u8) !BlockingResult {
+    std.debug.assert(self.is_blocking == false);
+
+    self.is_blocking = true;
+    defer {
+        self.is_blocking = false;
+
+        // we blocked evaluation while loading this script, there could be
+        // scripts ready to process.
+        self.evaluate();
     }
 
-    return URL.stitch(
-        arena,
-        specifier,
-        base,
-        .{ .alloc = .if_needed, .null_terminated = true },
-    );
-}
-
-pub fn getModule(self: *ScriptManager, url: [:0]const u8, referrer: []const u8) !void {
-    const gop = try self.sync_modules.getOrPut(self.allocator, url);
-    if (gop.found_existing) {
-        // already requested
-        return;
-    }
-    errdefer _ = self.sync_modules.remove(url);
-
-    const sync = try self.sync_module_pool.create();
-    errdefer self.sync_module_pool.destroy(sync);
-
-    sync.* = .{ .manager = self };
-    gop.value_ptr.* = sync;
-
-    var headers = try self.client.newHeaders();
-    try self.page.requestCookie(.{}).headersForRequest(self.page.arena, url, &headers);
-
-    log.debug(.http, "script queue", .{
-        .url = url,
-        .ctx = "module",
-        .referrer = referrer,
-        .stack = self.page.js.stackTrace() catch "???",
-    });
-
-    try self.client.request(.{
-        .url = url,
-        .ctx = sync,
-        .method = .GET,
-        .headers = headers,
-        .cookie_jar = self.page.cookie_jar,
-        .resource_type = .script,
-        .start_callback = if (log.enabled(.http, .debug)) SyncModule.startCallback else null,
-        .header_callback = SyncModule.headerCallback,
-        .data_callback = SyncModule.dataCallback,
-        .done_callback = SyncModule.doneCallback,
-        .error_callback = SyncModule.errorCallback,
-    });
-}
-
-pub fn waitForModule(self: *ScriptManager, url: [:0]const u8) !GetResult {
-    // Normally it's dangerous to hold on to map pointers. But here, the map
-    // can't change. It's possible that by calling `tick`, other entries within
-    // the map will have their value change, but the map itself is immutable
-    // during this tick.
-    const entry = self.sync_modules.getEntry(url) orelse {
-        return error.UnknownModule;
+    var blocking = Blocking{
+        .allocator = self.allocator,
+        .buffer_pool = &self.buffer_pool,
     };
-    const sync = entry.value_ptr.*;
 
-    // We can have multiple scripts waiting for the same module in concurrency.
-    // We use the waiters to ensures only the last waiter deinit the resources.
-    sync.waiters += 1;
-    defer sync.waiters -= 1;
+    var headers = try Http.Headers.init();
+    try self.page.requestCookie(.{}).headersForRequest(self.page.arena, url, &headers);
 
     var client = self.client;
-    while (true) {
-        switch (sync.state) {
-            .loading => {},
-            .done => {
-                if (sync.waiters == 1) {
-                    // Our caller has its own higher level cache (caching the
-                    // actual compiled module). There's no reason for us to keep
-                    // this if we are the last waiter.
-                    defer self.sync_module_pool.destroy(sync);
-                    defer self.sync_modules.removeByPtr(entry.key_ptr);
-                    return .{
-                        .shared = false,
-                        .buffer = sync.buffer,
-                        .buffer_pool = &self.buffer_pool,
-                    };
-                }
-
-                return .{
-                    .shared = true,
-                    .buffer = sync.buffer,
-                    .buffer_pool = &self.buffer_pool,
-                };
-            },
-            .err => |err| return err,
-        }
-        // rely on http's timeout settings to avoid an endless/long loop.
-        _ = try client.tick(200);
-    }
-}
-
-pub fn getAsyncModule(self: *ScriptManager, url: [:0]const u8, cb: AsyncModule.Callback, cb_data: *anyopaque, referrer: []const u8) !void {
-    const async = try self.async_module_pool.create();
-    errdefer self.async_module_pool.destroy(async);
-
-    async.* = .{
-        .cb = cb,
-        .manager = self,
-        .cb_data = cb_data,
-    };
-
-    var headers = try self.client.newHeaders();
-    try self.page.requestCookie(.{}).headersForRequest(self.page.arena, url, &headers);
-
-    log.debug(.http, "script queue", .{
-        .url = url,
-        .ctx = "dynamic module",
-        .referrer = referrer,
-        .stack = self.page.js.stackTrace() catch "???",
-    });
-
-    try self.client.request(.{
+    try client.blockingRequest(.{
         .url = url,
         .method = .GET,
         .headers = headers,
         .cookie_jar = self.page.cookie_jar,
-        .ctx = async,
+        .ctx = &blocking,
         .resource_type = .script,
-        .start_callback = if (log.enabled(.http, .debug)) AsyncModule.startCallback else null,
-        .header_callback = AsyncModule.headerCallback,
-        .data_callback = AsyncModule.dataCallback,
-        .done_callback = AsyncModule.doneCallback,
-        .error_callback = AsyncModule.errorCallback,
+        .start_callback = if (log.enabled(.http, .debug)) Blocking.startCallback else null,
+        .header_callback = Blocking.headerCallback,
+        .data_callback = Blocking.dataCallback,
+        .done_callback = Blocking.doneCallback,
+        .error_callback = Blocking.errorCallback,
     });
+
+    // rely on http's timeout settings to avoid an endless/long loop.
+    while (true) {
+        _ = try client.tick(200);
+        switch (blocking.state) {
+            .running => {},
+            .done => |result| return result,
+            .err => |err| return err,
+        }
+    }
 }
+
 pub fn staticScriptsDone(self: *ScriptManager) void {
     std.debug.assert(self.static_scripts_done == false);
     self.static_scripts_done = true;
-    self.evaluate();
 }
 
 // try to evaluate completed scripts (in order). This is called whenever a script
@@ -413,10 +318,24 @@ fn evaluate(self: *ScriptManager) void {
         return;
     }
 
+    if (self.is_blocking) {
+        // Cannot evaluate scripts while a blocking-load is in progress. Not
+        // only could that result in incorrect evaluation order, it could
+        // trigger another blocking request, while we're doing a blocking request.
+        return;
+    }
+
     const page = self.page;
     self.is_evaluating = true;
     defer self.is_evaluating = false;
 
+    // every script in asyncs_ready is ready to be evaluated.
+    while (self.asyncs_ready.first) |n| {
+        var pending_script: *PendingScript = @fieldParentPtr("node", n);
+        defer pending_script.deinit();
+        pending_script.script.eval(page);
+    }
+
     while (self.scripts.first) |n| {
         var pending_script: *PendingScript = @fieldParentPtr("node", n);
         if (pending_script.complete == false) {
@@ -466,12 +385,6 @@ pub fn isDone(self: *const ScriptManager) bool {
         self.deferreds.first == null; // and there are no more <script defer src=> to wait for
 }
 
-fn asyncScriptIsDone(self: *ScriptManager) void {
-    if (self.isDone()) {
-        self.page.documentIsComplete();
-    }
-}
-
 fn startCallback(transfer: *Http.Transfer) !void {
     const script: *PendingScript = @ptrCast(@alignCast(transfer.ctx));
     script.startCallback(transfer) catch |err| {
@@ -503,38 +416,6 @@ fn errorCallback(ctx: *anyopaque, err: anyerror) void {
     script.errorCallback(err);
 }
 
-fn parseImportmap(self: *ScriptManager, script: *const Script) !void {
-    const content = script.source.content();
-
-    const Imports = struct {
-        imports: std.json.ArrayHashMap([]const u8),
-    };
-
-    const imports = try std.json.parseFromSliceLeaky(
-        Imports,
-        self.page.arena,
-        content,
-        .{ .allocate = .alloc_always },
-    );
-
-    var iter = imports.imports.map.iterator();
-    while (iter.next()) |entry| {
-        // > Relative URLs are resolved to absolute URL addresses using the
-        // > base URL of the document containing the import map.
-        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules#importing_modules_using_import_maps
-        const resolved_url = try URL.stitch(
-            self.page.arena,
-            entry.value_ptr.*,
-            self.page.url.raw,
-            .{ .alloc = .if_needed, .null_terminated = true },
-        );
-
-        try self.importmap.put(self.page.arena, entry.key_ptr.*, resolved_url);
-    }
-
-    return;
-}
-
 // A script which is pending execution.
 // It could be pending because:
 //   (a) we're still downloading its content or
@@ -612,15 +493,11 @@ pub const PendingScript = struct {
 
         const manager = self.manager;
         self.complete = true;
-        if (!self.script.is_async) {
-            manager.evaluate();
-            return;
+        if (self.script.is_async) {
+            manager.asyncs.remove(&self.node);
+            manager.asyncs_ready.append(&self.node);
         }
-        // async script can be evaluated immediately
-        self.script.eval(manager.page);
-        self.deinit();
-        // asyncScriptIsDone must be run after the pending script is deinit.
-        manager.asyncScriptIsDone();
+        manager.evaluate();
     }
 
     fn errorCallback(self: *PendingScript, err: anyerror) void {
@@ -644,7 +521,7 @@ pub const PendingScript = struct {
 
         const script = &self.script;
         if (script.is_async) {
-            return &self.manager.asyncs;
+            return if (self.complete) &self.manager.asyncs_ready else &self.manager.asyncs;
         }
 
         if (script.is_defer) {
@@ -666,12 +543,11 @@ const Script = struct {
     const Kind = enum {
         module,
         javascript,
-        importmap,
     };
 
     const Callback = union(enum) {
         string: []const u8,
-        function: js.Function,
+        function: Env.Function,
     };
 
     const Source = union(enum) {
@@ -707,25 +583,8 @@ const Script = struct {
             .cacheable = cacheable,
         });
 
-        // Handle importmap special case here: the content is a JSON containing
-        // imports.
-        if (self.kind == .importmap) {
-            page.script_manager.parseImportmap(self) catch |err| {
-                log.err(.browser, "parse importmap script", .{
-                    .err = err,
-                    .src = url,
-                    .kind = self.kind,
-                    .cacheable = cacheable,
-                });
-                self.executeCallback("onerror", page);
-                return;
-            };
-            self.executeCallback("onload", page);
-            return;
-        }
-
-        const js_context = page.js;
-        var try_catch: js.TryCatch = undefined;
+        const js_context = page.main_context;
+        var try_catch: Env.TryCatch = undefined;
         try_catch.init(js_context);
         defer try_catch.deinit();
 
@@ -735,9 +594,8 @@ const Script = struct {
                 .javascript => _ = js_context.eval(content, url) catch break :blk false,
                 .module => {
                     // We don't care about waiting for the evaluation here.
-                    js_context.module(false, content, url, cacheable) catch break :blk false;
+                    _ = js_context.module(content, url, cacheable) catch break :blk false;
                 },
-                .importmap => unreachable, // handled before the try/catch.
             }
             break :blk true;
         };
@@ -768,11 +626,11 @@ const Script = struct {
 
         switch (callback) {
             .string => |str| {
-                var try_catch: js.TryCatch = undefined;
-                try_catch.init(page.js);
+                var try_catch: Env.TryCatch = undefined;
+                try_catch.init(page.main_context);
                 defer try_catch.deinit();
 
-                _ = page.js.exec(str, typ) catch |err| {
+                _ = page.main_context.exec(str, typ) catch |err| {
                     const msg = try_catch.err(page.arena) catch @errorName(err) orelse "unknown";
                     log.warn(.user_script, "script callback", .{
                         .url = self.url,
@@ -790,7 +648,7 @@ const Script = struct {
                 };
                 defer parser.eventDestroy(loadevt);
 
-                var result: js.Function.Result = undefined;
+                var result: Env.Function.Result = undefined;
                 const iface = Event.toInterface(loadevt);
                 f.tryCall(void, .{iface}, &result) catch {
                     log.warn(.user_script, "script callback", .{
@@ -893,17 +751,16 @@ const BufferPool = struct {
     }
 };
 
-const SyncModule = struct {
-    manager: *ScriptManager,
+const Blocking = struct {
+    allocator: Allocator,
+    buffer_pool: *BufferPool,
+    state: State = .{ .running = {} },
     buffer: std.ArrayListUnmanaged(u8) = .{},
-    state: State = .loading,
-    // number of waiters for the module.
-    waiters: u8 = 0,
 
     const State = union(enum) {
-        done,
-        loading,
+        running: void,
         err: anyerror,
+        done: BlockingResult,
     };
 
     fn startCallback(transfer: *Http.Transfer) !void {
@@ -919,13 +776,12 @@ const SyncModule = struct {
             .content_type = header.contentType(),
         });
 
-        var self: *SyncModule = @ptrCast(@alignCast(transfer.ctx));
         if (header.status != 200) {
-            self.finished(.{ .err = error.InvalidStatusCode });
             return error.InvalidStatusCode;
         }
 
-        self.buffer = self.manager.buffer_pool.get();
+        var self: *Blocking = @ptrCast(@alignCast(transfer.ctx));
+        self.buffer = self.buffer_pool.get();
     }
 
     fn dataCallback(transfer: *Http.Transfer, data: []const u8) !void {
@@ -935,8 +791,8 @@ const SyncModule = struct {
         //     .blocking = true,
         // });
 
-        var self: *SyncModule = @ptrCast(@alignCast(transfer.ctx));
-        self.buffer.appendSlice(self.manager.allocator, data) catch |err| {
+        var self: *Blocking = @ptrCast(@alignCast(transfer.ctx));
+        self.buffer.appendSlice(self.allocator, data) catch |err| {
             log.err(.http, "SM.dataCallback", .{
                 .err = err,
                 .len = data.len,
@@ -948,107 +804,29 @@ const SyncModule = struct {
     }
 
     fn doneCallback(ctx: *anyopaque) !void {
-        var self: *SyncModule = @ptrCast(@alignCast(ctx));
-        self.finished(.done);
-    }
-
-    fn errorCallback(ctx: *anyopaque, err: anyerror) void {
-        var self: *SyncModule = @ptrCast(@alignCast(ctx));
-        self.finished(.{ .err = err });
-    }
-
-    fn finished(self: *SyncModule, state: State) void {
-        self.state = state;
-    }
-};
-
-pub const AsyncModule = struct {
-    cb: Callback,
-    cb_data: *anyopaque,
-    manager: *ScriptManager,
-    buffer: std.ArrayListUnmanaged(u8) = .{},
-
-    pub const Callback = *const fn (ptr: *anyopaque, result: anyerror!GetResult) void;
-
-    fn startCallback(transfer: *Http.Transfer) !void {
-        log.debug(.http, "script fetch start", .{ .req = transfer, .async = true });
-    }
-
-    fn headerCallback(transfer: *Http.Transfer) !void {
-        const header = &transfer.response_header.?;
-        log.debug(.http, "script header", .{
-            .req = transfer,
-            .async = true,
-            .status = header.status,
-            .content_type = header.contentType(),
-        });
-
-        if (header.status != 200) {
-            return error.InvalidStatusCode;
-        }
-
-        var self: *AsyncModule = @ptrCast(@alignCast(transfer.ctx));
-        self.buffer = self.manager.buffer_pool.get();
-    }
-
-    fn dataCallback(transfer: *Http.Transfer, data: []const u8) !void {
-        // too verbose
-        // log.debug(.http, "script data chunk", .{
-        //     .req = transfer,
-        //     .blocking = true,
-        // });
-
-        var self: *AsyncModule = @ptrCast(@alignCast(transfer.ctx));
-        self.buffer.appendSlice(self.manager.allocator, data) catch |err| {
-            log.err(.http, "SM.dataCallback", .{
-                .err = err,
-                .len = data.len,
-                .ascyn = true,
-                .transfer = transfer,
-            });
-            return err;
-        };
-    }
-
-    fn doneCallback(ctx: *anyopaque) !void {
-        var self: *AsyncModule = @ptrCast(@alignCast(ctx));
-        defer self.manager.async_module_pool.destroy(self);
-        self.cb(self.cb_data, .{
-            .shared = false,
+        var self: *Blocking = @ptrCast(@alignCast(ctx));
+        self.state = .{ .done = .{
             .buffer = self.buffer,
-            .buffer_pool = &self.manager.buffer_pool,
-        });
+            .buffer_pool = self.buffer_pool,
+        } };
     }
 
     fn errorCallback(ctx: *anyopaque, err: anyerror) void {
-        var self: *AsyncModule = @ptrCast(@alignCast(ctx));
-
-        if (err != error.Abort) {
-            self.cb(self.cb_data, err);
-        }
-
-        if (self.buffer.items.len > 0) {
-            self.manager.buffer_pool.release(self.buffer);
-        }
-
-        self.manager.async_module_pool.destroy(self);
+        var self: *Blocking = @ptrCast(@alignCast(ctx));
+        self.state = .{ .err = err };
+        self.buffer_pool.release(self.buffer);
     }
 };
 
-pub const GetResult = struct {
+pub const BlockingResult = struct {
     buffer: std.ArrayListUnmanaged(u8),
     buffer_pool: *BufferPool,
-    shared: bool,
 
-    pub fn deinit(self: *GetResult) void {
-        // if the result is shared, don't deinit.
-        if (self.shared) {
-            return;
-        }
+    pub fn deinit(self: *BlockingResult) void {
         self.buffer_pool.release(self.buffer);
     }
 
-    pub fn src(self: *const GetResult) []const u8 {
+    pub fn src(self: *const BlockingResult) []const u8 {
         return self.buffer.items;
     }
 };

src/browser/SlotChangeMonitor.zig

@@ -1,189 +0,0 @@
-const std = @import("std");
-
-const log = @import("../log.zig");
-const parser = @import("netsurf.zig");
-const collection = @import("dom/html_collection.zig");
-
-const Page = @import("page.zig").Page;
-
-const SlotChangeMonitor = @This();
-
-page: *Page,
-event_node: parser.EventNode,
-slots_changed: std.ArrayList(*parser.Slot),
-
-// Monitors the document in order to trigger slotchange events.
-pub fn init(page: *Page) !*SlotChangeMonitor {
-    // on the heap, we need a stable address for event_node
-    const self = try page.arena.create(SlotChangeMonitor);
-    self.* = .{
-        .page = page,
-        .slots_changed = .empty,
-        .event_node = .{ .func = mutationCallback },
-    };
-    const root = parser.documentToNode(parser.documentHTMLToDocument(page.window.document));
-
-    _ = try parser.eventTargetAddEventListener(
-        parser.toEventTarget(parser.Node, root),
-        "DOMNodeInserted",
-        &self.event_node,
-        false,
-    );
-
-    _ = try parser.eventTargetAddEventListener(
-        parser.toEventTarget(parser.Node, root),
-        "DOMNodeRemoved",
-        &self.event_node,
-        false,
-    );
-
-    _ = try parser.eventTargetAddEventListener(
-        parser.toEventTarget(parser.Node, root),
-        "DOMAttrModified",
-        &self.event_node,
-        false,
-    );
-
-    return self;
-}
-
-// Given a element, finds its slot, if any.
-pub fn findSlot(element: *parser.Element, page: *const Page) !?*parser.Slot {
-    const target_name = (try parser.elementGetAttribute(element, "slot")) orelse return null;
-    return findNamedSlot(element, target_name, page);
-}
-
-// Given an element and a name, find the slo, if any. This is only useful for
-// MutationEvents where findSlot is unreliable because parser.elementGetAttribute(element, "slot")
-// could return the new or old value.
-fn findNamedSlot(element: *parser.Element, target_name: []const u8, page: *const Page) !?*parser.Slot {
-    // I believe elements need to be added as direct descendents of the host,
-    // so we don't need to go find the host, we just grab the parent.
-    const host = parser.nodeParentNode(@ptrCast(element)) orelse return null;
-    const state = page.getNodeState(host) orelse return null;
-    const shadow_root = state.shadow_root orelse return null;
-
-    // if we're here, we found a host, now find the slot
-    var nodes = collection.HTMLCollectionByTagName(
-        @ptrCast(@alignCast(shadow_root.proto)),
-        "slot",
-        .{ .include_root = false },
-    );
-    for (0..1000) |i| {
-        const n = (try nodes.item(@intCast(i))) orelse return null;
-        const slot_name = (try parser.elementGetAttribute(@ptrCast(n), "name")) orelse "";
-        if (std.mem.eql(u8, target_name, slot_name)) {
-            return @ptrCast(n);
-        }
-    }
-    return null;
-}
-
-// Event callback from the mutation event, signaling either the addition of
-// a node, removal of a node, or a change in attribute
-fn mutationCallback(en: *parser.EventNode, event: *parser.Event) void {
-    const mutation_event = parser.eventToMutationEvent(event);
-    const self: *SlotChangeMonitor = @fieldParentPtr("event_node", en);
-    self._mutationCallback(mutation_event) catch |err| {
-        log.err(.web_api, "slot change callback", .{ .err = err });
-    };
-}
-
-fn _mutationCallback(self: *SlotChangeMonitor, event: *parser.MutationEvent) !void {
-    const event_type = parser.eventType(@ptrCast(event));
-    if (std.mem.eql(u8, event_type, "DOMNodeInserted")) {
-        const event_target = parser.eventTarget(@ptrCast(event)) orelse return;
-        return self.nodeAddedOrRemoved(@ptrCast(event_target));
-    }
-
-    if (std.mem.eql(u8, event_type, "DOMNodeRemoved")) {
-        const event_target = parser.eventTarget(@ptrCast(event)) orelse return;
-        return self.nodeAddedOrRemoved(@ptrCast(event_target));
-    }
-
-    if (std.mem.eql(u8, event_type, "DOMAttrModified")) {
-        const attribute_name = try parser.mutationEventAttributeName(event);
-        if (std.mem.eql(u8, attribute_name, "slot") == false) {
-            return;
-        }
-
-        const new_value = parser.mutationEventNewValue(event);
-        const prev_value = parser.mutationEventPrevValue(event);
-        const event_target = parser.eventTarget(@ptrCast(event)) orelse return;
-        return self.nodeAttributeChanged(@ptrCast(event_target), new_value, prev_value);
-    }
-}
-
-// A node was removed or added. If it's an element, and if it has a slot attribute
-// then we'll dispatch a slotchange event.
-fn nodeAddedOrRemoved(self: *SlotChangeMonitor, node: *parser.Node) !void {
-    if (parser.nodeType(node) != .element) {
-        return;
-    }
-    const el: *parser.Element = @ptrCast(node);
-    if (try findSlot(el, self.page)) |slot| {
-        return self.scheduleSlotChange(slot);
-    }
-}
-
-// An attribute was modified. If the attribute is "slot", then we'll trigger 1
-// slotchange for the old slot (if there was one) and 1 slotchange for the new
-// one (if there is one)
-fn nodeAttributeChanged(self: *SlotChangeMonitor, node: *parser.Node, new_value: ?[]const u8, prev_value: ?[]const u8) !void {
-    if (parser.nodeType(node) != .element) {
-        return;
-    }
-
-    const el: *parser.Element = @ptrCast(node);
-    if (try findNamedSlot(el, prev_value orelse "", self.page)) |slot| {
-        try self.scheduleSlotChange(slot);
-    }
-
-    if (try findNamedSlot(el, new_value orelse "", self.page)) |slot| {
-        try self.scheduleSlotChange(slot);
-    }
-}
-
-// OK. Our MutationEvent is not a MutationObserver - it's an older, deprecated
-// API. It gets dispatched in the middle of the change. While I'm sure it has
-// some rules, from our point of view, it fires too early. DOMAttrModified fires
-// before the attribute is actually updated and DOMNodeRemoved before the node
-// is actually removed. This is a problem if the callback will call
-// `slot.assignedNodes`, since that won't return the new state.
-// So, we use the page schedule to schedule the dispatching of the slotchange
-// event.
-fn scheduleSlotChange(self: *SlotChangeMonitor, slot: *parser.Slot) !void {
-    for (self.slots_changed.items) |changed| {
-        if (slot == changed) {
-            return;
-        }
-    }
-
-    try self.slots_changed.append(self.page.arena, slot);
-    if (self.slots_changed.items.len == 1) {
-        // first item added, schedule the callback
-        try self.page.scheduler.add(self, scheduleCallback, 0, .{ .name = "slot change" });
-    }
-}
-
-// Callback from the schedule. Time to dispatch the slotchange event
-fn scheduleCallback(ctx: *anyopaque) ?u32 {
-    var self: *SlotChangeMonitor = @ptrCast(@alignCast(ctx));
-    self._scheduleCallback() catch |err| {
-        log.err(.app, "slot change schedule", .{ .err = err });
-    };
-    return null;
-}
-
-fn _scheduleCallback(self: *SlotChangeMonitor) !void {
-    for (self.slots_changed.items) |slot| {
-        const event = try parser.eventCreate();
-        defer parser.eventDestroy(event);
-        try parser.eventInit(event, "slotchange", .{});
-        _ = try parser.eventTargetDispatchEvent(
-            parser.toEventTarget(parser.Element, @ptrCast(@alignCast(slot))),
-            event,
-        );
-    }
-    self.slots_changed.clearRetainingCapacity();
-}

src/browser/State.zig

@@ -26,16 +26,17 @@
 // this quickly proved necessary, since different fields are needed on the same
 // data at different levels of the prototype chain. This isn't memory efficient.
 
-const js = @import("js/js.zig");
+const Env = @import("env.zig").Env;
 const parser = @import("netsurf.zig");
 const DataSet = @import("html/DataSet.zig");
 const ShadowRoot = @import("dom/shadow_root.zig").ShadowRoot;
 const StyleSheet = @import("cssom/StyleSheet.zig");
+const CSSStyleSheet = @import("cssom/CSSStyleSheet.zig");
 const CSSStyleDeclaration = @import("cssom/CSSStyleDeclaration.zig");
 
 // for HTMLScript (but probably needs to be added to more)
-onload: ?js.Function = null,
-onerror: ?js.Function = null,
+onload: ?Env.Function = null,
+onerror: ?Env.Function = null,
 
 // for HTMLElement
 style: CSSStyleDeclaration = .empty,
@@ -53,7 +54,7 @@ style_sheet: ?*StyleSheet = null,
 
 // for dom/document
 active_element: ?*parser.Element = null,
-adopted_style_sheets: ?js.Object = null,
+adopted_style_sheets: ?Env.JsObject = null,
 
 // for HTMLSelectElement
 // By default, if no option is explicitly selected, the first option should

src/browser/browser.zig

@@ -21,8 +21,8 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
 
-const js = @import("js/js.zig");
 const State = @import("State.zig");
+const Env = @import("env.zig").Env;
 const App = @import("../app.zig").App;
 const Session = @import("session.zig").Session;
 const Notification = @import("../notification.zig").Notification;
@@ -34,12 +34,11 @@ const HttpClient = @import("../http/Client.zig");
 // You can create multiple browser instances.
 // A browser contains only one session.
 pub const Browser = struct {
-    env: *js.Env,
+    env: *Env,
     app: *App,
     session: ?Session,
     allocator: Allocator,
     http_client: *HttpClient,
-    call_arena: ArenaAllocator,
     page_arena: ArenaAllocator,
     session_arena: ArenaAllocator,
     transfer_arena: ArenaAllocator,
@@ -49,7 +48,7 @@ pub const Browser = struct {
     pub fn init(app: *App) !Browser {
         const allocator = app.allocator;
 
-        const env = try js.Env.init(allocator, &app.platform, .{});
+        const env = try Env.init(allocator, &app.platform, .{});
         errdefer env.deinit();
 
         const notification = try Notification.init(allocator, app.notification);
@@ -64,7 +63,6 @@ pub const Browser = struct {
             .allocator = allocator,
             .notification = notification,
             .http_client = app.http.client,
-            .call_arena = ArenaAllocator.init(allocator),
             .page_arena = ArenaAllocator.init(allocator),
             .session_arena = ArenaAllocator.init(allocator),
             .transfer_arena = ArenaAllocator.init(allocator),
@@ -75,7 +73,6 @@ pub const Browser = struct {
     pub fn deinit(self: *Browser) void {
         self.closeSession();
         self.env.deinit();
-        self.call_arena.deinit();
         self.page_arena.deinit();
         self.session_arena.deinit();
         self.transfer_arena.deinit();

src/browser/console/console.zig

@@ -20,47 +20,48 @@ const std = @import("std");
 const builtin = @import("builtin");
 const log = @import("../../log.zig");
 
-const js = @import("../js/js.zig");
+const Allocator = std.mem.Allocator;
 const Page = @import("../page.zig").Page;
+const JsObject = @import("../env.zig").Env.JsObject;
 
 pub const Console = struct {
     // TODO: configurable writer
     timers: std.StringHashMapUnmanaged(u32) = .{},
     counts: std.StringHashMapUnmanaged(u32) = .{},
 
-    pub fn _lp(values: []js.Object, page: *Page) !void {
+    pub fn _lp(values: []JsObject, page: *Page) !void {
         if (values.len == 0) {
             return;
         }
         log.fatal(.console, "lightpanda", .{ .args = try serializeValues(values, page) });
     }
 
-    pub fn _log(values: []js.Object, page: *Page) !void {
+    pub fn _log(values: []JsObject, page: *Page) !void {
         if (values.len == 0) {
             return;
         }
         log.info(.console, "info", .{ .args = try serializeValues(values, page) });
     }
 
-    pub fn _info(values: []js.Object, page: *Page) !void {
+    pub fn _info(values: []JsObject, page: *Page) !void {
         return _log(values, page);
     }
 
-    pub fn _debug(values: []js.Object, page: *Page) !void {
+    pub fn _debug(values: []JsObject, page: *Page) !void {
         if (values.len == 0) {
             return;
         }
         log.debug(.console, "debug", .{ .args = try serializeValues(values, page) });
     }
 
-    pub fn _warn(values: []js.Object, page: *Page) !void {
+    pub fn _warn(values: []JsObject, page: *Page) !void {
         if (values.len == 0) {
             return;
         }
         log.warn(.console, "warn", .{ .args = try serializeValues(values, page) });
     }
 
-    pub fn _error(values: []js.Object, page: *Page) !void {
+    pub fn _error(values: []JsObject, page: *Page) !void {
         if (values.len == 0) {
             return;
         }
@@ -71,16 +72,6 @@ pub const Console = struct {
         });
     }
 
-    pub fn _trace(values: []js.Object, page: *Page) !void {
-        if (values.len == 0) {
-            return;
-        }
-        log.debug(.console, "debug", .{
-            .stack = page.js.stackTrace() catch "???",
-            .args = try serializeValues(values, page),
-        });
-    }
-
     pub fn _clear() void {}
 
     pub fn _count(self: *Console, label_: ?[]const u8, page: *Page) !void {
@@ -142,7 +133,7 @@ pub const Console = struct {
         log.warn(.console, "timer stop", .{ .label = label, .elapsed = elapsed - kv.value });
     }
 
-    pub fn _assert(assertion: js.Object, values: []js.Object, page: *Page) !void {
+    pub fn _assert(assertion: JsObject, values: []JsObject, page: *Page) !void {
         if (assertion.isTruthy()) {
             return;
         }
@@ -153,7 +144,7 @@ pub const Console = struct {
         log.info(.console, "assertion failed", .{ .values = serialized_values });
     }
 
-    fn serializeValues(values: []js.Object, page: *Page) ![]const u8 {
+    fn serializeValues(values: []JsObject, page: *Page) ![]const u8 {
         if (values.len == 0) {
             return "";
         }

src/browser/crypto/crypto.zig

@@ -17,14 +17,14 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const uuidv4 = @import("../../id.zig").uuidv4;
 
 // https://w3c.github.io/webcrypto/#crypto-interface
 pub const Crypto = struct {
     _not_empty: bool = true,
 
-    pub fn _getRandomValues(_: *const Crypto, js_obj: js.Object) !js.Object {
+    pub fn _getRandomValues(_: *const Crypto, js_obj: Env.JsObject) !Env.JsObject {
         var into = try js_obj.toZig(Crypto, "getRandomValues", RandomValues);
         const buf = into.asBuffer();
         if (buf.len > 65_536) {

src/browser/css/css.zig

@@ -46,15 +46,17 @@ pub fn parse(alloc: std.mem.Allocator, s: []const u8, opts: parser.ParseOptions)
 // matchFirst call m.match with the first node that matches the selector s, from the
 // descendants of n and returns true. If none matches, it returns false.
 pub fn matchFirst(s: *const Selector, node: anytype, m: anytype) !bool {
-    var child = node.firstChild();
-    while (child) |c| {
-        if (try s.match(c)) {
-            try m.match(c);
+    var c = try node.firstChild();
+    while (true) {
+        if (c == null) break;
+
+        if (try s.match(c.?)) {
+            try m.match(c.?);
             return true;
         }
 
-        if (try matchFirst(s, c, m)) return true;
-        child = c.nextSibling();
+        if (try matchFirst(s, c.?, m)) return true;
+        c = try c.?.nextSibling();
     }
     return false;
 }
@@ -62,11 +64,13 @@ pub fn matchFirst(s: *const Selector, node: anytype, m: anytype) !bool {
 // matchAll call m.match with the all the nodes that matches the selector s, from the
 // descendants of n.
 pub fn matchAll(s: *const Selector, node: anytype, m: anytype) !void {
-    var child = node.firstChild();
-    while (child) |c| {
-        if (try s.match(c)) try m.match(c);
-        try matchAll(s, c, m);
-        child = c.nextSibling();
+    var c = try node.firstChild();
+    while (true) {
+        if (c == null) break;
+
+        if (try s.match(c.?)) try m.match(c.?);
+        try matchAll(s, c.?, m);
+        c = try c.?.nextSibling();
     }
 }
 

src/browser/css/libdom.zig

@@ -26,67 +26,71 @@ const Allocator = std.mem.Allocator;
 pub const Node = struct {
     node: *parser.Node,
 
-    pub fn firstChild(n: Node) ?Node {
-        const c = parser.nodeFirstChild(n.node);
+    pub fn firstChild(n: Node) !?Node {
+        const c = try parser.nodeFirstChild(n.node);
         if (c) |cc| return .{ .node = cc };
 
         return null;
     }
 
-    pub fn lastChild(n: Node) ?Node {
-        const c = parser.nodeLastChild(n.node);
+    pub fn lastChild(n: Node) !?Node {
+        const c = try parser.nodeLastChild(n.node);
         if (c) |cc| return .{ .node = cc };
 
         return null;
     }
 
-    pub fn nextSibling(n: Node) ?Node {
-        const c = parser.nodeNextSibling(n.node);
+    pub fn nextSibling(n: Node) !?Node {
+        const c = try parser.nodeNextSibling(n.node);
         if (c) |cc| return .{ .node = cc };
 
         return null;
     }
 
-    pub fn prevSibling(n: Node) ?Node {
-        const c = parser.nodePreviousSibling(n.node);
+    pub fn prevSibling(n: Node) !?Node {
+        const c = try parser.nodePreviousSibling(n.node);
         if (c) |cc| return .{ .node = cc };
 
         return null;
     }
 
-    pub fn parent(n: Node) ?Node {
-        const c = parser.nodeParentNode(n.node);
+    pub fn parent(n: Node) !?Node {
+        const c = try parser.nodeParentNode(n.node);
         if (c) |cc| return .{ .node = cc };
 
         return null;
     }
 
     pub fn isElement(n: Node) bool {
-        return parser.nodeType(n.node) == .element;
+        const t = parser.nodeType(n.node) catch return false;
+        return t == .element;
     }
 
     pub fn isDocument(n: Node) bool {
-        return parser.nodeType(n.node) == .document;
+        const t = parser.nodeType(n.node) catch return false;
+        return t == .document;
     }
 
     pub fn isComment(n: Node) bool {
-        return parser.nodeType(n.node) == .comment;
+        const t = parser.nodeType(n.node) catch return false;
+        return t == .comment;
     }
 
     pub fn isText(n: Node) bool {
-        return parser.nodeType(n.node) == .text;
+        const t = parser.nodeType(n.node) catch return false;
+        return t == .text;
     }
 
-    pub fn text(n: Node) ?[]const u8 {
-        const data = parser.nodeTextContent(n.node);
+    pub fn text(n: Node) !?[]const u8 {
+        const data = try parser.nodeTextContent(n.node);
         if (data == null) return null;
         if (data.?.len == 0) return null;
 
         return std.mem.trim(u8, data.?, &std.ascii.whitespace);
     }
 
-    pub fn isEmptyText(n: Node) bool {
-        const data = parser.nodeTextContent(n.node);
+    pub fn isEmptyText(n: Node) !bool {
+        const data = try parser.nodeTextContent(n.node);
         if (data == null) return true;
         if (data.?.len == 0) return true;
 
@@ -94,7 +98,7 @@ pub const Node = struct {
     }
 
     pub fn tag(n: Node) ![]const u8 {
-        return parser.nodeName(n.node);
+        return try parser.nodeName(n.node);
     }
 
     pub fn attr(n: Node, key: []const u8) !?[]const u8 {
@@ -136,7 +140,7 @@ const MatcherTest = struct {
 test "Browser.CSS.Libdom: matchFirst" {
     const alloc = std.testing.allocator;
 
-    parser.init();
+    try parser.init();
     defer parser.deinit();
 
     var matcher = MatcherTest.init(alloc);
@@ -281,7 +285,7 @@ test "Browser.CSS.Libdom: matchFirst" {
 test "Browser.CSS.Libdom: matchAll" {
     const alloc = std.testing.allocator;
 
-    parser.init();
+    try parser.init();
     defer parser.deinit();
 
     var matcher = MatcherTest.init(alloc);

src/browser/css/parser.zig

@@ -821,8 +821,7 @@ pub const Parser = struct {
 // nameStart returns whether c can be the first character of an identifier
 // (not counting an initial hyphen, or an escape sequence).
 fn nameStart(c: u8) bool {
-    return 'a' <= c and c <= 'z' or 'A' <= c and c <= 'Z' or c == '_' or c > 127 or
-        '0' <= c and c <= '9';
+    return 'a' <= c and c <= 'z' or 'A' <= c and c <= 'Z' or c == '_' or c > 127;
 }
 
 // nameChar returns whether c can be a character within an identifier
@@ -891,7 +890,7 @@ test "parser.parseIdentifier" {
         err: bool = false,
     }{
         .{ .s = "x", .exp = "x" },
-        .{ .s = "96", .exp = "96", .err = false },
+        .{ .s = "96", .exp = "", .err = true },
         .{ .s = "-x", .exp = "-x" },
         .{ .s = "r\\e9 sumé", .exp = "résumé" },
         .{ .s = "r\\0000e9 sumé", .exp = "résumé" },
@@ -976,7 +975,6 @@ test "parser.parse" {
         .{ .s = ":root", .exp = .{ .pseudo_class = .root } },
         .{ .s = ".\\:bar", .exp = .{ .class = ":bar" } },
         .{ .s = ".foo\\:bar", .exp = .{ .class = "foo:bar" } },
-        .{ .s = "[class=75c0fa18a94b9e3a6b8e14d6cbe688a27f5da10a]", .exp = .{ .attribute = .{ .key = "class", .val = "75c0fa18a94b9e3a6b8e14d6cbe688a27f5da10a", .op = .eql } } },
     };
 
     for (testcases) |tc| {

src/browser/css/selector.zig

@@ -334,39 +334,41 @@ pub const Selector = union(enum) {
                         if (!try v.second.match(n)) return false;
 
                         // The first must match a ascendent.
-                        var parent = n.parent();
-                        while (parent) |p| {
-                            if (try v.first.match(p)) {
+                        var p = try n.parent();
+                        while (p != null) {
+                            if (try v.first.match(p.?)) {
                                 return true;
                             }
-                            parent = p.parent();
+                            p = try p.?.parent();
                         }
 
                         return false;
                     },
                     .child => {
-                        const p = n.parent() orelse return false;
-                        return try v.second.match(n) and try v.first.match(p);
+                        const p = try n.parent();
+                        if (p == null) return false;
+
+                        return try v.second.match(n) and try v.first.match(p.?);
                     },
                     .next_sibling => {
                         if (!try v.second.match(n)) return false;
-                        var child = n.prevSibling();
-                        while (child) |c| {
-                            if (c.isText() or c.isComment()) {
-                                child = c.prevSibling();
+                        var c = try n.prevSibling();
+                        while (c != null) {
+                            if (c.?.isText() or c.?.isComment()) {
+                                c = try c.?.prevSibling();
                                 continue;
                             }
-                            return try v.first.match(c);
+                            return try v.first.match(c.?);
                         }
                         return false;
                     },
                     .subsequent_sibling => {
                         if (!try v.second.match(n)) return false;
 
-                        var child = n.prevSibling();
-                        while (child) |c| {
-                            if (try v.first.match(c)) return true;
-                            child = c.prevSibling();
+                        var c = try n.prevSibling();
+                        while (c != null) {
+                            if (try v.first.match(c.?)) return true;
+                            c = try c.?.prevSibling();
                         }
                         return false;
                     },
@@ -436,10 +438,10 @@ pub const Selector = union(enum) {
                 // Only containsOwn is implemented.
                 if (v.own == false) return Error.UnsupportedContainsPseudoClass;
 
-                var child = n.firstChild();
-                while (child) |c| {
-                    if (c.isText()) {
-                        const text = c.text();
+                var c = try n.firstChild();
+                while (c != null) {
+                    if (c.?.isText()) {
+                        const text = try c.?.text();
                         if (text) |_text| {
                             if (contains(_text, v.val, false)) { // we are case sensitive. Is this correct behavior?
                                 return true;
@@ -447,7 +449,7 @@ pub const Selector = union(enum) {
                         }
                     }
 
-                    child = c.nextSibling();
+                    c = try c.?.nextSibling();
                 }
                 return false;
             },
@@ -475,16 +477,16 @@ pub const Selector = union(enum) {
                     .empty => {
                         if (!n.isElement()) return false;
 
-                        var child = n.firstChild();
-                        while (child) |c| {
-                            if (c.isElement()) return false;
+                        var c = try n.firstChild();
+                        while (c != null) {
+                            if (c.?.isElement()) return false;
 
-                            if (c.isText()) {
-                                if (c.isEmptyText()) continue;
+                            if (c.?.isText()) {
+                                if (try c.?.isEmptyText()) continue;
                                 return false;
                             }
 
-                            child = c.nextSibling();
+                            c = try c.?.nextSibling();
                         }
 
                         return true;
@@ -492,7 +494,7 @@ pub const Selector = union(enum) {
                     .root => {
                         if (!n.isElement()) return false;
 
-                        const p = n.parent();
+                        const p = try n.parent();
                         return (p != null and p.?.isDocument());
                     },
                     .link => {
@@ -562,7 +564,7 @@ pub const Selector = union(enum) {
 
                         const ntag = try n.tag();
 
-                        if (std.ascii.eqlIgnoreCase("input", ntag)) {
+                        if (std.ascii.eqlIgnoreCase("intput", ntag)) {
                             const ntype = try n.attr("type");
                             if (ntype == null) return false;
 
@@ -607,23 +609,24 @@ pub const Selector = union(enum) {
     }
 
     fn hasLegendInPreviousSiblings(n: anytype) anyerror!bool {
-        var child = n.prevSibling();
-        while (child) |c| {
-            const ctag = try c.tag();
+        var c = try n.prevSibling();
+        while (c != null) {
+            const ctag = try c.?.tag();
             if (std.ascii.eqlIgnoreCase("legend", ctag)) return true;
-            child = c.prevSibling();
+            c = try c.?.prevSibling();
         }
         return false;
     }
 
     fn inDisabledFieldset(n: anytype) anyerror!bool {
-        const p = n.parent() orelse return false;
+        const p = try n.parent();
+        if (p == null) return false;
 
         const ntag = try n.tag();
-        const ptag = try p.tag();
+        const ptag = try p.?.tag();
 
         if (std.ascii.eqlIgnoreCase("fieldset", ptag) and
-            try p.attr("disabled") != null and
+            try p.?.attr("disabled") != null and
             (!std.ascii.eqlIgnoreCase("legend", ntag) or try hasLegendInPreviousSiblings(n)))
         {
             return true;
@@ -639,7 +642,7 @@ pub const Selector = union(enum) {
         // ```
         // https://github.com/andybalholm/cascadia/blob/master/pseudo_classes.go#L434
 
-        return try inDisabledFieldset(p);
+        return try inDisabledFieldset(p.?);
     }
 
     fn langMatch(lang: []const u8, n: anytype) anyerror!bool {
@@ -653,8 +656,10 @@ pub const Selector = union(enum) {
         }
 
         // if the tag doesn't match, try the parent.
-        const p = n.parent() orelse return false;
-        return langMatch(lang, p);
+        const p = try n.parent();
+        if (p == null) return false;
+
+        return langMatch(lang, p.?);
     }
 
     // onlyChildMatch implements :only-child
@@ -662,24 +667,25 @@ pub const Selector = union(enum) {
     fn onlyChildMatch(of_type: bool, n: anytype) anyerror!bool {
         if (!n.isElement()) return false;
 
-        const p = n.parent() orelse return false;
+        const p = try n.parent();
+        if (p == null) return false;
 
         const ntag = try n.tag();
 
         var count: usize = 0;
-        var child = p.firstChild();
+        var c = try p.?.firstChild();
         // loop hover all n siblings.
-        while (child) |c| {
+        while (c != null) {
             // ignore non elements or others tags if of-type is true.
-            if (!c.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.tag()))) {
-                child = c.nextSibling();
+            if (!c.?.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.?.tag()))) {
+                c = try c.?.nextSibling();
                 continue;
             }
 
             count += 1;
             if (count > 1) return false;
 
-            child = c.nextSibling();
+            c = try c.?.nextSibling();
         }
 
         return count == 1;
@@ -690,25 +696,27 @@ pub const Selector = union(enum) {
     fn simpleNthLastChildMatch(b: isize, of_type: bool, n: anytype) anyerror!bool {
         if (!n.isElement()) return false;
 
-        const p = n.parent() orelse return false;
+        const p = try n.parent();
+        if (p == null) return false;
+
         const ntag = try n.tag();
 
         var count: isize = 0;
-        var child = p.lastChild();
+        var c = try p.?.lastChild();
         // loop hover all n siblings.
-        while (child) |c| {
+        while (c != null) {
             // ignore non elements or others tags if of-type is true.
-            if (!c.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.tag()))) {
-                child = c.prevSibling();
+            if (!c.?.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.?.tag()))) {
+                c = try c.?.prevSibling();
                 continue;
             }
 
             count += 1;
 
-            if (n.eql(c)) return count == b;
+            if (n.eql(c.?)) return count == b;
             if (count >= b) return false;
 
-            child = c.prevSibling();
+            c = try c.?.prevSibling();
         }
 
         return false;
@@ -719,25 +727,27 @@ pub const Selector = union(enum) {
     fn simpleNthChildMatch(b: isize, of_type: bool, n: anytype) anyerror!bool {
         if (!n.isElement()) return false;
 
-        const p = n.parent() orelse return false;
+        const p = try n.parent();
+        if (p == null) return false;
+
         const ntag = try n.tag();
 
         var count: isize = 0;
-        var child = p.firstChild();
+        var c = try p.?.firstChild();
         // loop hover all n siblings.
-        while (child) |c| {
+        while (c != null) {
             // ignore non elements or others tags if of-type is true.
-            if (!c.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.tag()))) {
-                child = c.nextSibling();
+            if (!c.?.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.?.tag()))) {
+                c = try c.?.nextSibling();
                 continue;
             }
 
             count += 1;
 
-            if (n.eql(c)) return count == b;
+            if (n.eql(c.?)) return count == b;
             if (count >= b) return false;
 
-            child = c.nextSibling();
+            c = try c.?.nextSibling();
         }
 
         return false;
@@ -749,27 +759,29 @@ pub const Selector = union(enum) {
     fn nthChildMatch(a: isize, b: isize, last: bool, of_type: bool, n: anytype) anyerror!bool {
         if (!n.isElement()) return false;
 
-        const p = n.parent() orelse return false;
+        const p = try n.parent();
+        if (p == null) return false;
+
         const ntag = try n.tag();
 
         var i: isize = -1;
         var count: isize = 0;
-        var child = p.firstChild();
+        var c = try p.?.firstChild();
         // loop hover all n siblings.
-        while (child) |c| {
+        while (c != null) {
             // ignore non elements or others tags if of-type is true.
-            if (!c.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.tag()))) {
-                child = c.nextSibling();
+            if (!c.?.isElement() or (of_type and !std.mem.eql(u8, ntag, try c.?.tag()))) {
+                c = try c.?.nextSibling();
                 continue;
             }
             count += 1;
 
-            if (n.eql(c)) {
+            if (n.eql(c.?)) {
                 i = count;
                 if (!last) break;
             }
 
-            child = c.nextSibling();
+            c = try c.?.nextSibling();
         }
 
         if (i == -1) return false;
@@ -782,21 +794,21 @@ pub const Selector = union(enum) {
     }
 
     fn hasDescendantMatch(s: *const Selector, n: anytype) anyerror!bool {
-        var child = n.firstChild();
-        while (child) |c| {
-            if (try s.match(c)) return true;
-            if (c.isElement() and try hasDescendantMatch(s, c)) return true;
-            child = c.nextSibling();
+        var c = try n.firstChild();
+        while (c != null) {
+            if (try s.match(c.?)) return true;
+            if (c.?.isElement() and try hasDescendantMatch(s, c.?)) return true;
+            c = try c.?.nextSibling();
         }
 
         return false;
     }
 
     fn hasChildMatch(s: *const Selector, n: anytype) anyerror!bool {
-        var child = n.firstChild();
-        while (child) |c| {
-            if (try s.match(c)) return true;
-            child = c.nextSibling();
+        var c = try n.firstChild();
+        while (c != null) {
+            if (try s.match(c.?)) return true;
+            c = try c.?.nextSibling();
         }
 
         return false;
@@ -847,23 +859,23 @@ pub const NodeTest = struct {
     name: []const u8 = "",
     att: ?[]const u8 = null,
 
-    pub fn firstChild(n: *const NodeTest) ?*const NodeTest {
+    pub fn firstChild(n: *const NodeTest) !?*const NodeTest {
         return n.child;
     }
 
-    pub fn lastChild(n: *const NodeTest) ?*const NodeTest {
+    pub fn lastChild(n: *const NodeTest) !?*const NodeTest {
         return n.last;
     }
 
-    pub fn nextSibling(n: *const NodeTest) ?*const NodeTest {
+    pub fn nextSibling(n: *const NodeTest) !?*const NodeTest {
         return n.sibling;
     }
 
-    pub fn prevSibling(n: *const NodeTest) ?*const NodeTest {
+    pub fn prevSibling(n: *const NodeTest) !?*const NodeTest {
         return n.prev;
     }
 
-    pub fn parent(n: *const NodeTest) ?*const NodeTest {
+    pub fn parent(n: *const NodeTest) !?*const NodeTest {
         return n.par;
     }
 
@@ -879,7 +891,7 @@ pub const NodeTest = struct {
         return false;
     }
 
-    pub fn text(_: *const NodeTest) ?[]const u8 {
+    pub fn text(_: *const NodeTest) !?[]const u8 {
         return null;
     }
 
@@ -887,7 +899,7 @@ pub const NodeTest = struct {
         return false;
     }
 
-    pub fn isEmptyText(_: *const NodeTest) bool {
+    pub fn isEmptyText(_: *const NodeTest) !bool {
         return false;
     }
 
@@ -981,11 +993,6 @@ test "Browser.CSS.Selector: matchFirst" {
             .n = .{ .child = &.{ .name = "p", .sibling = &.{ .name = "p", .att = "bar" } } },
             .exp = 0,
         },
-        .{
-            .q = "[foo=1baz]",
-            .n = .{ .child = &.{ .name = "p", .sibling = &.{ .name = "p", .att = "bar" } } },
-            .exp = 0,
-        },
         .{
             .q = "[foo!=bar]",
             .n = .{ .child = &.{ .name = "p", .sibling = &.{ .name = "p", .att = "bar" } } },

src/browser/cssom/CSSRuleList.zig

@@ -19,6 +19,7 @@
 const std = @import("std");
 
 const CSSRule = @import("CSSRule.zig");
+const StyleSheet = @import("StyleSheet.zig").StyleSheet;
 
 const CSSImportRule = CSSRule.CSSImportRule;
 

src/browser/cssom/CSSStyleSheet.zig

@@ -18,7 +18,7 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 const StyleSheet = @import("StyleSheet.zig");
 const CSSRuleList = @import("CSSRuleList.zig");
@@ -73,13 +73,15 @@ pub fn _deleteRule(self: *CSSStyleSheet, index: usize) !void {
     _ = self.css_rules.list.orderedRemove(index);
 }
 
-pub fn _replace(self: *CSSStyleSheet, text: []const u8, page: *Page) !js.Promise {
+pub fn _replace(self: *CSSStyleSheet, text: []const u8, page: *Page) !Env.Promise {
     _ = self;
     _ = text;
     // TODO: clear self.css_rules
     // parse text and re-populate self.css_rules
 
-    return page.js.resolvePromise({});
+    const resolver = page.main_context.createPromiseResolver();
+    try resolver.resolve({});
+    return resolver.promise();
 }
 
 pub fn _replaceSync(self: *CSSStyleSheet, text: []const u8) !void {

src/browser/dom/Animation.zig

@@ -18,17 +18,19 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const Page = @import("../page.zig").Page;
+const JsObject = @import("../env.zig").JsObject;
+const Promise = @import("../env.zig").Promise;
+const PromiseResolver = @import("../env.zig").PromiseResolver;
 
 const Animation = @This();
 
-effect: ?js.Object,
-timeline: ?js.Object,
-ready_resolver: ?js.PromiseResolver,
-finished_resolver: ?js.PromiseResolver,
+effect: ?JsObject,
+timeline: ?JsObject,
+ready_resolver: ?PromiseResolver,
+finished_resolver: ?PromiseResolver,
 
-pub fn constructor(effect: ?js.Object, timeline: ?js.Object) !Animation {
+pub fn constructor(effect: ?JsObject, timeline: ?JsObject) !Animation {
     return .{
         .effect = if (effect) |eo| try eo.persist() else null,
         .timeline = if (timeline) |to| try to.persist() else null,
@@ -47,37 +49,37 @@ pub fn get_pending(self: *const Animation) bool {
     return false;
 }
 
-pub fn get_finished(self: *Animation, page: *Page) !js.Promise {
+pub fn get_finished(self: *Animation, page: *Page) !Promise {
     if (self.finished_resolver == null) {
-        const resolver = page.js.createPromiseResolver(.none);
+        const resolver = page.main_context.createPromiseResolver();
         try resolver.resolve(self);
         self.finished_resolver = resolver;
     }
     return self.finished_resolver.?.promise();
 }
 
-pub fn get_ready(self: *Animation, page: *Page) !js.Promise {
+pub fn get_ready(self: *Animation, page: *Page) !Promise {
     // never resolved, because we're always "finished"
     if (self.ready_resolver == null) {
-        const resolver = page.js.createPromiseResolver(.none);
+        const resolver = page.main_context.createPromiseResolver();
         self.ready_resolver = resolver;
     }
     return self.ready_resolver.?.promise();
 }
 
-pub fn get_effect(self: *const Animation) ?js.Object {
+pub fn get_effect(self: *const Animation) ?JsObject {
     return self.effect;
 }
 
-pub fn set_effect(self: *Animation, effect: js.Object) !void {
+pub fn set_effect(self: *Animation, effect: JsObject) !void {
     self.effect = try effect.persist();
 }
 
-pub fn get_timeline(self: *const Animation) ?js.Object {
+pub fn get_timeline(self: *const Animation) ?JsObject {
     return self.timeline;
 }
 
-pub fn set_timeline(self: *Animation, timeline: js.Object) !void {
+pub fn set_timeline(self: *Animation, timeline: JsObject) !void {
     self.timeline = try timeline.persist();
 }
 

src/browser/dom/IntersectionObserver.zig

@@ -1,329 +0,0 @@
-// Copyright (C) 2023-2025  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-
-const js = @import("../js/js.zig");
-const log = @import("../../log.zig");
-const parser = @import("../netsurf.zig");
-const Page = @import("../page.zig").Page;
-const Node = @import("node.zig").Node;
-const Element = @import("element.zig").Element;
-
-pub const Interfaces = .{
-    IntersectionObserver,
-    Entry,
-};
-
-// This implementation attempts to be as less wrong as possible. Since we don't
-// render, or know how things are positioned, our best guess isn't very good.
-const IntersectionObserver = @This();
-page: *Page,
-root: *parser.Node,
-callback: js.Function,
-event_node: parser.EventNode,
-observed_entries: std.ArrayList(Entry),
-pending_elements: std.ArrayList(*parser.Element),
-ready_elements: std.ArrayList(*parser.Element),
-
-pub fn constructor(callback: js.Function, opts_: ?IntersectionObserverOptions, page: *Page) !*IntersectionObserver {
-    const opts = opts_ orelse IntersectionObserverOptions{};
-
-    const self = try page.arena.create(IntersectionObserver);
-    self.* = .{
-        .page = page,
-        .callback = callback,
-        .ready_elements = .{},
-        .observed_entries = .{},
-        .pending_elements = .{},
-        .event_node = .{ .func = mutationCallback },
-        .root = opts.root orelse parser.documentToNode(parser.documentHTMLToDocument(page.window.document)),
-    };
-
-    _ = try parser.eventTargetAddEventListener(
-        parser.toEventTarget(parser.Node, self.root),
-        "DOMNodeInserted",
-        &self.event_node,
-        false,
-    );
-
-    _ = try parser.eventTargetAddEventListener(
-        parser.toEventTarget(parser.Node, self.root),
-        "DOMNodeRemoved",
-        &self.event_node,
-        false,
-    );
-
-    return self;
-}
-
-pub fn _disconnect(self: *IntersectionObserver) !void {
-    // We don't free as it is on an arena
-    self.ready_elements = .{};
-    self.observed_entries = .{};
-    self.pending_elements = .{};
-}
-
-pub fn _observe(self: *IntersectionObserver, target_element: *parser.Element, page: *Page) !void {
-    for (self.observed_entries.items) |*observer| {
-        if (observer.target == target_element) {
-            return; // Already observed
-        }
-    }
-
-    if (self.isPending(target_element)) {
-        return; // Already pending
-    }
-
-    for (self.ready_elements.items) |element| {
-        if (element == target_element) {
-            return; // Already primed
-        }
-    }
-
-    // We can never fire callbacks synchronously. Code like React expects any
-    // callback to fire in the future (e.g. via microtasks).
-    try self.ready_elements.append(self.page.arena, target_element);
-    if (self.ready_elements.items.len == 1) {
-        // this is our first ready entry, schedule a callback
-        try page.scheduler.add(self, processReady, 0, .{
-            .name = "intersection ready",
-        });
-    }
-}
-
-pub fn _unobserve(self: *IntersectionObserver, target: *parser.Element) !void {
-    if (self.removeObserved(target)) {
-        return;
-    }
-
-    for (self.ready_elements.items, 0..) |el, index| {
-        if (el == target) {
-            _ = self.ready_elements.swapRemove(index);
-            return;
-        }
-    }
-
-    for (self.pending_elements.items, 0..) |el, index| {
-        if (el == target) {
-            _ = self.pending_elements.swapRemove(index);
-            return;
-        }
-    }
-}
-
-pub fn _takeRecords(self: *IntersectionObserver) []Entry {
-    return self.observed_entries.items;
-}
-
-fn processReady(ctx: *anyopaque) ?u32 {
-    const self: *IntersectionObserver = @ptrCast(@alignCast(ctx));
-    self._processReady() catch |err| {
-        log.err(.web_api, "intersection ready", .{ .err = err });
-    };
-    return null;
-}
-
-fn _processReady(self: *IntersectionObserver) !void {
-    defer self.ready_elements.clearRetainingCapacity();
-    for (self.ready_elements.items) |element| {
-        // IntersectionObserver probably doesn't work like what your intuition
-        // thinks. As long as a node has a parent, even if that parent isn't
-        // connected and even if the two nodes don't intersect, it'll fire the
-        // callback once.
-        if (try Node.get_parentNode(@ptrCast(element)) == null) {
-            if (!self.isPending(element)) {
-                try self.pending_elements.append(self.page.arena, element);
-            }
-            continue;
-        }
-        try self.forceObserve(element);
-    }
-}
-
-fn isPending(self: *IntersectionObserver, element: *parser.Element) bool {
-    for (self.pending_elements.items) |el| {
-        if (el == element) {
-            return true;
-        }
-    }
-    return false;
-}
-
-fn mutationCallback(en: *parser.EventNode, event: *parser.Event) void {
-    const mutation_event = parser.eventToMutationEvent(event);
-    const self: *IntersectionObserver = @fieldParentPtr("event_node", en);
-    self._mutationCallback(mutation_event) catch |err| {
-        log.err(.web_api, "mutation callback", .{ .err = err, .source = "intersection observer" });
-    };
-}
-
-fn _mutationCallback(self: *IntersectionObserver, event: *parser.MutationEvent) !void {
-    const event_type = parser.eventType(@ptrCast(event));
-
-    if (std.mem.eql(u8, event_type, "DOMNodeInserted")) {
-        const node = parser.mutationEventRelatedNode(event) catch return orelse return;
-        if (parser.nodeType(node) != .element) {
-            return;
-        }
-        const el: *parser.Element = @ptrCast(node);
-        if (self.removePending(el)) {
-            // It was pending (because it wasn't in the root), but now it is
-            // we should observe it.
-            try self.forceObserve(el);
-        }
-        return;
-    }
-
-    if (std.mem.eql(u8, event_type, "DOMNodeRemoved")) {
-        const node = parser.mutationEventRelatedNode(event) catch return orelse return;
-        if (parser.nodeType(node) != .element) {
-            return;
-        }
-
-        const el: *parser.Element = @ptrCast(node);
-        if (self.removeObserved(el)) {
-            // It _was_ observed, it no longer is in our root, but if it was
-            // to get re-added, it should be observed again (I think), so
-            // we add it to our pending list
-            try self.pending_elements.append(self.page.arena, el);
-        }
-
-        return;
-    }
-
-    // impossible event type
-    unreachable;
-}
-
-// Exists to skip the checks made _observe when called from a DOMNodeInserted
-// event. In such events, the event handler has alread done the necessary
-// checks.
-fn forceObserve(self: *IntersectionObserver, target: *parser.Element) !void {
-    try self.observed_entries.append(self.page.arena, .{
-        .page = self.page,
-        .root = self.root,
-        .target = target,
-    });
-
-    var result: js.Function.Result = undefined;
-    self.callback.tryCall(void, .{self.observed_entries.items}, &result) catch {
-        log.debug(.user_script, "callback error", .{
-            .err = result.exception,
-            .stack = result.stack,
-            .source = "intersection observer",
-        });
-    };
-}
-
-fn removeObserved(self: *IntersectionObserver, target: *parser.Element) bool {
-    for (self.observed_entries.items, 0..) |*observer, index| {
-        if (observer.target == target) {
-            _ = self.observed_entries.swapRemove(index);
-            return true;
-        }
-    }
-    return false;
-}
-
-fn removePending(self: *IntersectionObserver, target: *parser.Element) bool {
-    for (self.pending_elements.items, 0..) |el, index| {
-        if (el == target) {
-            _ = self.pending_elements.swapRemove(index);
-            return true;
-        }
-    }
-    return false;
-}
-
-const IntersectionObserverOptions = struct {
-    root: ?*parser.Node = null, // Element or Document
-    rootMargin: ?[]const u8 = "0px 0px 0px 0px",
-    threshold: ?Threshold = .{ .single = 0.0 },
-
-    const Threshold = union(enum) {
-        single: f32,
-        list: []const f32,
-    };
-};
-
-// https://developer.mozilla.org/en-US/docs/Web/API/Entry
-// https://w3c.github.io/IntersectionObserver/#intersection-observer-entry
-pub const Entry = struct {
-    page: *Page,
-    root: *parser.Node,
-    target: *parser.Element,
-
-    // Returns the bounds rectangle of the target element as a DOMRectReadOnly. The bounds are computed as described in the documentation for Element.getBoundingClientRect().
-    pub fn get_boundingClientRect(self: *const Entry) !Element.DOMRect {
-        return Element._getBoundingClientRect(self.target, self.page);
-    }
-
-    // Returns the ratio of the intersectionRect to the boundingClientRect.
-    pub fn get_intersectionRatio(_: *const Entry) f32 {
-        return 1.0;
-    }
-
-    // Returns a DOMRectReadOnly representing the target's visible area.
-    pub fn get_intersectionRect(self: *const Entry) !Element.DOMRect {
-        return Element._getBoundingClientRect(self.target, self.page);
-    }
-
-    // A Boolean value which is true if the target element intersects with the
-    // intersection observer's root. If this is true, then, the
-    // Entry describes a transition into a state of
-    // intersection; if it's false, then you know the transition is from
-    // intersecting to not-intersecting.
-    pub fn get_isIntersecting(_: *const Entry) bool {
-        return true;
-    }
-
-    // Returns a DOMRectReadOnly for the intersection observer's root.
-    pub fn get_rootBounds(self: *const Entry) !Element.DOMRect {
-        const root = self.root;
-        if (@intFromPtr(root) == @intFromPtr(self.page.window.document)) {
-            return self.page.renderer.boundingRect();
-        }
-
-        const root_type = parser.nodeType(root);
-
-        var element: *parser.Element = undefined;
-        switch (root_type) {
-            .element => element = parser.nodeToElement(root),
-            .document => {
-                const doc = parser.nodeToDocument(root);
-                element = (try parser.documentGetDocumentElement(doc)).?;
-            },
-            else => return error.InvalidState,
-        }
-
-        return Element._getBoundingClientRect(element, self.page);
-    }
-
-    // The Element whose intersection with the root changed.
-    pub fn get_target(self: *const Entry) *parser.Element {
-        return self.target;
-    }
-
-    // TODO: pub fn get_time(self: *const Entry)
-};
-
-const testing = @import("../../testing.zig");
-test "Browser: DOM.IntersectionObserver" {
-    try testing.htmlRunner("dom/intersection_observer.html");
-}

src/browser/dom/MessageChannel.zig

@@ -20,11 +20,13 @@ const std = @import("std");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
 
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 const EventTarget = @import("../dom/event_target.zig").EventTarget;
 const EventHandler = @import("../events/event.zig").EventHandler;
 
+const JsObject = Env.JsObject;
+const Function = Env.Function;
 const Allocator = std.mem.Allocator;
 
 const MAX_QUEUE_SIZE = 10;
@@ -70,28 +72,29 @@ pub const MessagePort = struct {
     pair: *MessagePort,
     closed: bool = false,
     started: bool = false,
-    onmessage_cbk: ?js.Function = null,
-    onmessageerror_cbk: ?js.Function = null,
+    onmessage_cbk: ?Function = null,
+    onmessageerror_cbk: ?Function = null,
     // This is the queue of messages to dispatch to THIS MessagePort when the
     // MessagePort is started.
-    queue: std.ArrayListUnmanaged(js.Object) = .empty,
+    queue: std.ArrayListUnmanaged(JsObject) = .empty,
 
     pub const PostMessageOption = union(enum) {
-        transfer: js.Object,
+        transfer: JsObject,
         options: Opts,
 
         pub const Opts = struct {
-            transfer: js.Object,
+            transfer: JsObject,
         };
     };
 
-    pub fn _postMessage(self: *MessagePort, obj: js.Object, opts_: ?PostMessageOption, page: *Page) !void {
+    pub fn _postMessage(self: *MessagePort, obj: JsObject, opts_: ?PostMessageOption, page: *Page) !void {
         if (self.closed) {
             return;
         }
 
         if (opts_ != null) {
             log.warn(.web_api, "not implemented", .{ .feature = "MessagePort postMessage options" });
+            return error.NotImplemented;
         }
 
         try self.pair.dispatchOrQueue(obj, page.arena);
@@ -122,10 +125,10 @@ pub const MessagePort = struct {
         self.pair.closed = true;
     }
 
-    pub fn get_onmessage(self: *MessagePort) ?js.Function {
+    pub fn get_onmessage(self: *MessagePort) ?Function {
         return self.onmessage_cbk;
     }
-    pub fn get_onmessageerror(self: *MessagePort) ?js.Function {
+    pub fn get_onmessageerror(self: *MessagePort) ?Function {
         return self.onmessageerror_cbk;
     }
 
@@ -150,7 +153,7 @@ pub const MessagePort = struct {
 
     // called from our pair. If port1.postMessage("x") is called, then this
     // will be called on port2.
-    fn dispatchOrQueue(self: *MessagePort, obj: js.Object, arena: Allocator) !void {
+    fn dispatchOrQueue(self: *MessagePort, obj: JsObject, arena: Allocator) !void {
         // our pair should have checked this already
         std.debug.assert(self.closed == false);
 
@@ -165,7 +168,7 @@ pub const MessagePort = struct {
         return self.queue.append(arena, try obj.persist());
     }
 
-    fn dispatch(self: *MessagePort, obj: js.Object) !void {
+    fn dispatch(self: *MessagePort, obj: JsObject) !void {
         // obj is already persisted, don't use `MessageEvent.constructor`, but
         // go directly to `init`, which assumes persisted objects.
         var evt = try MessageEvent.init(.{ .data = obj });
@@ -180,7 +183,7 @@ pub const MessagePort = struct {
         alloc: Allocator,
         typ: []const u8,
         listener: EventHandler.Listener,
-    ) !?js.Function {
+    ) !?Function {
         const target = @as(*parser.EventTarget, @ptrCast(self));
         const eh = (try EventHandler.register(alloc, target, typ, listener, null)) orelse unreachable;
         return eh.callback;
@@ -205,12 +208,12 @@ pub const MessageEvent = struct {
     pub const union_make_copy = true;
 
     proto: parser.Event,
-    data: ?js.Object,
+    data: ?JsObject,
 
     // You would think if port1 sends to port2, the source would be port2
     // (which is how I read the documentation), but it appears to always be
     // null. It can always be set explicitly via the constructor;
-    source: ?js.Object,
+    source: ?JsObject,
 
     origin: []const u8,
 
@@ -224,8 +227,8 @@ pub const MessageEvent = struct {
     ports: []*MessagePort,
 
     const Options = struct {
-        data: ?js.Object = null,
-        source: ?js.Object = null,
+        data: ?JsObject = null,
+        source: ?JsObject = null,
         origin: []const u8 = "",
         lastEventId: []const u8 = "",
         ports: []*MessagePort = &.{},
@@ -241,7 +244,7 @@ pub const MessageEvent = struct {
         });
     }
 
-    // This is like "constructor", but it assumes js.Objects have already been
+    // This is like "constructor", but it assumes JsObjects have already been
     // persisted. Necessary because this `new MessageEvent()` can be called
     // directly from JS OR from a port.postMessage. In the latter case, data
     // may have already been persisted (as it might need to be queued);
@@ -261,7 +264,7 @@ pub const MessageEvent = struct {
         };
     }
 
-    pub fn get_data(self: *const MessageEvent) !?js.Object {
+    pub fn get_data(self: *const MessageEvent) !?JsObject {
         return self.data;
     }
 
@@ -269,7 +272,7 @@ pub const MessageEvent = struct {
         return self.origin;
     }
 
-    pub fn get_source(self: *const MessageEvent) ?js.Object {
+    pub fn get_source(self: *const MessageEvent) ?JsObject {
         return self.source;
     }
 

src/browser/dom/attribute.zig

@@ -25,24 +25,24 @@ pub const Attr = struct {
     pub const prototype = *Node;
     pub const subtype = .node;
 
-    pub fn get_namespaceURI(self: *parser.Attribute) ?[]const u8 {
-        return parser.nodeGetNamespace(parser.attributeToNode(self));
+    pub fn get_namespaceURI(self: *parser.Attribute) !?[]const u8 {
+        return try parser.nodeGetNamespace(parser.attributeToNode(self));
     }
 
-    pub fn get_prefix(self: *parser.Attribute) ?[]const u8 {
-        return parser.nodeGetPrefix(parser.attributeToNode(self));
+    pub fn get_prefix(self: *parser.Attribute) !?[]const u8 {
+        return try parser.nodeGetPrefix(parser.attributeToNode(self));
     }
 
     pub fn get_localName(self: *parser.Attribute) ![]const u8 {
-        return parser.nodeLocalName(parser.attributeToNode(self));
+        return try parser.nodeLocalName(parser.attributeToNode(self));
     }
 
     pub fn get_name(self: *parser.Attribute) ![]const u8 {
-        return parser.attributeGetName(self);
+        return try parser.attributeGetName(self);
     }
 
     pub fn get_value(self: *parser.Attribute) !?[]const u8 {
-        return parser.attributeGetValue(self);
+        return try parser.attributeGetValue(self);
     }
 
     pub fn set_value(self: *parser.Attribute, v: []const u8) !?[]const u8 {

src/browser/dom/character_data.zig

@@ -51,7 +51,7 @@ pub const CharacterData = struct {
     }
 
     pub fn get_nextElementSibling(self: *parser.CharacterData) !?ElementUnion {
-        const res = parser.nodeNextElementSibling(parser.characterDataToNode(self));
+        const res = try parser.nodeNextElementSibling(parser.characterDataToNode(self));
         if (res == null) {
             return null;
         }
@@ -59,7 +59,7 @@ pub const CharacterData = struct {
     }
 
     pub fn get_previousElementSibling(self: *parser.CharacterData) !?ElementUnion {
-        const res = parser.nodePreviousElementSibling(parser.characterDataToNode(self));
+        const res = try parser.nodePreviousElementSibling(parser.characterDataToNode(self));
         if (res == null) {
             return null;
         }
@@ -68,8 +68,8 @@ pub const CharacterData = struct {
 
     // Read/Write attributes
 
-    pub fn get_data(self: *parser.CharacterData) []const u8 {
-        return parser.characterDataData(self);
+    pub fn get_data(self: *parser.CharacterData) ![]const u8 {
+        return try parser.characterDataData(self);
     }
 
     pub fn set_data(self: *parser.CharacterData, data: []const u8) !void {
@@ -96,18 +96,18 @@ pub const CharacterData = struct {
     }
 
     pub fn _substringData(self: *parser.CharacterData, offset: u32, count: u32) ![]const u8 {
-        return parser.characterDataSubstringData(self, offset, count);
+        return try parser.characterDataSubstringData(self, offset, count);
     }
 
     // netsurf's CharacterData (text, comment) doesn't implement the
     // dom_node_get_attributes and thus will crash if we try to call nodeIsEqualNode.
-    pub fn _isEqualNode(self: *parser.CharacterData, other_node: *parser.Node) bool {
-        if (parser.nodeType(@ptrCast(@alignCast(self))) != parser.nodeType(other_node)) {
+    pub fn _isEqualNode(self: *parser.CharacterData, other_node: *parser.Node) !bool {
+        if (try parser.nodeType(@ptrCast(@alignCast(self))) != try parser.nodeType(other_node)) {
             return false;
         }
 
         const other: *parser.CharacterData = @ptrCast(other_node);
-        if (std.mem.eql(u8, get_data(self), get_data(other)) == false) {
+        if (std.mem.eql(u8, try get_data(self), try get_data(other)) == false) {
             return false;
         }
 

src/browser/dom/document.zig

@@ -17,9 +17,8 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const log = @import("../../log.zig");
 
-const js = @import("../js/js.zig");
+const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
 const Page = @import("../page.zig").Page;
 
@@ -39,6 +38,8 @@ const Range = @import("range.zig").Range;
 
 const CustomEvent = @import("../events/custom_event.zig").CustomEvent;
 
+const Env = @import("../env.zig").Env;
+
 const DOMImplementation = @import("implementation.zig").DOMImplementation;
 
 // WEB IDL https://dom.spec.whatwg.org/#document
@@ -155,14 +156,22 @@ pub const Document = struct {
     // the spec changed to return an HTMLCollection instead.
     // That's why we reimplemented getElementsByTagName by using an
     // HTMLCollection in zig here.
-    pub fn _getElementsByTagName(self: *parser.Document, tag_name: js.String) !collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(parser.documentToNode(self), tag_name.string, .{
+    pub fn _getElementsByTagName(
+        self: *parser.Document,
+        tag_name: []const u8,
+        page: *Page,
+    ) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(page.arena, parser.documentToNode(self), tag_name, .{
             .include_root = true,
         });
     }
 
-    pub fn _getElementsByClassName(self: *parser.Document, class_names: js.String) !collection.HTMLCollection {
-        return collection.HTMLCollectionByClassName(parser.documentToNode(self), class_names.string, .{
+    pub fn _getElementsByClassName(
+        self: *parser.Document,
+        classNames: []const u8,
+        page: *Page,
+    ) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByClassName(page.arena, parser.documentToNode(self), classNames, .{
             .include_root = true,
         });
     }
@@ -299,26 +308,21 @@ pub const Document = struct {
         return &.{};
     }
 
-    pub fn get_adoptedStyleSheets(self: *parser.Document, page: *Page) !js.Object {
+    pub fn get_adoptedStyleSheets(self: *parser.Document, page: *Page) !Env.JsObject {
         const state = try page.getOrCreateNodeState(@ptrCast(@alignCast(self)));
         if (state.adopted_style_sheets) |obj| {
             return obj;
         }
 
-        const obj = try page.js.createArray(0).persist();
+        const obj = try page.main_context.newArray(0).persist();
         state.adopted_style_sheets = obj;
         return obj;
     }
 
-    pub fn set_adoptedStyleSheets(self: *parser.Document, sheets: js.Object, page: *Page) !void {
+    pub fn set_adoptedStyleSheets(self: *parser.Document, sheets: Env.JsObject, page: *Page) !void {
         const state = try page.getOrCreateNodeState(@ptrCast(@alignCast(self)));
         state.adopted_style_sheets = try sheets.persist();
     }
-
-    pub fn _hasFocus(_: *parser.Document) bool {
-        log.debug(.web_api, "not implemented", .{ .feature = "Document hasFocus" });
-        return true;
-    }
 };
 
 const testing = @import("../../testing.zig");

src/browser/dom/document_fragment.zig

@@ -38,8 +38,8 @@ pub const DocumentFragment = struct {
         );
     }
 
-    pub fn _isEqualNode(self: *parser.DocumentFragment, other_node: *parser.Node) bool {
-        const other_type = parser.nodeType(other_node);
+    pub fn _isEqualNode(self: *parser.DocumentFragment, other_node: *parser.Node) !bool {
+        const other_type = try parser.nodeType(other_node);
         if (other_type != .document_fragment) {
             return false;
         }

src/browser/dom/document_type.zig

@@ -29,21 +29,21 @@ pub const DocumentType = struct {
     pub const subtype = .node;
 
     pub fn get_name(self: *parser.DocumentType) ![]const u8 {
-        return parser.documentTypeGetName(self);
+        return try parser.documentTypeGetName(self);
     }
 
-    pub fn get_publicId(self: *parser.DocumentType) []const u8 {
-        return parser.documentTypeGetPublicId(self);
+    pub fn get_publicId(self: *parser.DocumentType) ![]const u8 {
+        return try parser.documentTypeGetPublicId(self);
     }
 
-    pub fn get_systemId(self: *parser.DocumentType) []const u8 {
-        return parser.documentTypeGetSystemId(self);
+    pub fn get_systemId(self: *parser.DocumentType) ![]const u8 {
+        return try parser.documentTypeGetSystemId(self);
     }
 
     // netsurf's DocumentType doesn't implement the dom_node_get_attributes
     // and thus will crash if we try to call nodeIsEqualNode.
     pub fn _isEqualNode(self: *parser.DocumentType, other_node: *parser.Node) !bool {
-        if (parser.nodeType(other_node) != .document_type) {
+        if (try parser.nodeType(other_node) != .document_type) {
             return false;
         }
 
@@ -51,10 +51,10 @@ pub const DocumentType = struct {
         if (std.mem.eql(u8, try get_name(self), try get_name(other)) == false) {
             return false;
         }
-        if (std.mem.eql(u8, get_publicId(self), get_publicId(other)) == false) {
+        if (std.mem.eql(u8, try get_publicId(self), try get_publicId(other)) == false) {
             return false;
         }
-        if (std.mem.eql(u8, get_systemId(self), get_systemId(other)) == false) {
+        if (std.mem.eql(u8, try get_systemId(self), try get_systemId(other)) == false) {
             return false;
         }
         return true;

src/browser/dom/dom.zig

@@ -25,6 +25,7 @@ const NodeList = @import("nodelist.zig");
 const Node = @import("node.zig");
 const ResizeObserver = @import("resize_observer.zig");
 const MutationObserver = @import("mutation_observer.zig");
+const IntersectionObserver = @import("intersection_observer.zig");
 const DOMParser = @import("dom_parser.zig").DOMParser;
 const TreeWalker = @import("tree_walker.zig").TreeWalker;
 const NodeIterator = @import("node_iterator.zig").NodeIterator;
@@ -43,6 +44,7 @@ pub const Interfaces = .{
     Node.Interfaces,
     ResizeObserver.Interfaces,
     MutationObserver.Interfaces,
+    IntersectionObserver.Interfaces,
     DOMParser,
     TreeWalker,
     NodeIterator,
@@ -52,5 +54,4 @@ pub const Interfaces = .{
     @import("range.zig").Interfaces,
     @import("Animation.zig"),
     @import("MessageChannel.zig").Interfaces,
-    @import("IntersectionObserver.zig").Interfaces,
 };

src/browser/dom/element.zig

@@ -18,7 +18,6 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
 const Page = @import("../page.zig").Page;
 
@@ -34,6 +33,7 @@ const HTMLElem = @import("../html/elements.zig");
 const ShadowRoot = @import("../dom/shadow_root.zig").ShadowRoot;
 
 const Animation = @import("Animation.zig");
+const JsObject = @import("../env.zig").JsObject;
 
 pub const Union = @import("../html/elements.zig").Union;
 
@@ -61,7 +61,7 @@ pub const Element = struct {
     pub fn toInterfaceT(comptime T: type, e: *parser.Element) !T {
         const tagname = try parser.elementGetTagName(e) orelse {
             // If the owner's document is HTML, assume we have an HTMLElement.
-            const doc = parser.nodeOwnerDocument(parser.elementToNode(e));
+            const doc = try parser.nodeOwnerDocument(parser.elementToNode(e));
             if (doc != null and !doc.?.is_html) {
                 return .{ .HTMLElement = @as(*parser.ElementHTML, @ptrCast(e)) };
             }
@@ -73,7 +73,7 @@ pub const Element = struct {
 
         const tag = parser.Tag.fromString(tagname) catch {
             // If the owner's document is HTML, assume we have an HTMLElement.
-            const doc = parser.nodeOwnerDocument(parser.elementToNode(e));
+            const doc = try parser.nodeOwnerDocument(parser.elementToNode(e));
             if (doc != null and doc.?.is_html) {
                 return .{ .HTMLElement = @as(*parser.ElementHTML, @ptrCast(e)) };
             }
@@ -87,12 +87,12 @@ pub const Element = struct {
     // JS funcs
     // --------
 
-    pub fn get_namespaceURI(self: *parser.Element) ?[]const u8 {
-        return parser.nodeGetNamespace(parser.elementToNode(self));
+    pub fn get_namespaceURI(self: *parser.Element) !?[]const u8 {
+        return try parser.nodeGetNamespace(parser.elementToNode(self));
     }
 
-    pub fn get_prefix(self: *parser.Element) ?[]const u8 {
-        return parser.nodeGetPrefix(parser.elementToNode(self));
+    pub fn get_prefix(self: *parser.Element) !?[]const u8 {
+        return try parser.nodeGetPrefix(parser.elementToNode(self));
     }
 
     pub fn get_localName(self: *parser.Element) ![]const u8 {
@@ -103,14 +103,6 @@ pub const Element = struct {
         return try parser.nodeName(parser.elementToNode(self));
     }
 
-    pub fn get_dir(self: *parser.Element) ![]const u8 {
-        return try parser.elementGetAttribute(self, "dir") orelse "";
-    }
-
-    pub fn set_dir(self: *parser.Element, dir: []const u8) !void {
-        return parser.elementSetAttribute(self, "dir", dir);
-    }
-
     pub fn get_id(self: *parser.Element) ![]const u8 {
         return try parser.elementGetAttribute(self, "id") orelse "";
     }
@@ -135,10 +127,6 @@ pub const Element = struct {
         return try parser.elementSetAttribute(self, "slot", slot);
     }
 
-    pub fn get_assignedSlot(self: *parser.Element, page: *const Page) !?*parser.Slot {
-        return @import("../SlotChangeMonitor.zig").findSlot(self, page);
-    }
-
     pub fn get_classList(self: *parser.Element) !*parser.TokenList {
         return try parser.tokenListCreate(self, "class");
     }
@@ -162,7 +150,7 @@ pub const Element = struct {
 
     pub fn set_innerHTML(self: *parser.Element, str: []const u8, page: *Page) !void {
         const node = parser.elementToNode(self);
-        const doc = parser.nodeOwnerDocument(node) orelse return parser.DOMError.WrongDocument;
+        const doc = try parser.nodeOwnerDocument(node) orelse return parser.DOMError.WrongDocument;
         // parse the fragment
         const fragment = try parser.documentParseFragmentFromStr(doc, str);
 
@@ -180,9 +168,9 @@ pub const Element = struct {
         // or an actual document. In a blank page, something like:
         //    x.innerHTML = '<script></script>';
         // does _not_ create an empty script, but in a real page, it does. Weird.
-        const html = parser.nodeFirstChild(fragment_node) orelse return;
-        const head = parser.nodeFirstChild(html) orelse return;
-        const body = parser.nodeNextSibling(head) orelse return;
+        const html = try parser.nodeFirstChild(fragment_node) orelse return;
+        const head = try parser.nodeFirstChild(html) orelse return;
+        const body = try parser.nodeNextSibling(head) orelse return;
 
         if (try parser.elementTag(self) == .template) {
             // HTMLElementTemplate is special. We don't append these as children
@@ -191,9 +179,11 @@ pub const Element = struct {
             // a new fragment
             const clean = try parser.documentCreateDocumentFragment(doc);
             const children = try parser.nodeGetChildNodes(body);
-            // always index 0, because nodeAppendChild moves the node out of
-            // the nodeList and into the new tree
-            while (parser.nodeListItem(children, 0)) |child| {
+            const ln = try parser.nodeListLength(children);
+            for (0..ln) |_| {
+                // always index 0, because nodeAppendChild moves the node out of
+                // the nodeList and into the new tree
+                const child = try parser.nodeListItem(children, 0) orelse continue;
                 _ = try parser.nodeAppendChild(@ptrCast(@alignCast(clean)), child);
             }
 
@@ -207,102 +197,27 @@ pub const Element = struct {
         {
             // First, copy some of the head element
             const children = try parser.nodeGetChildNodes(head);
-            // always index 0, because nodeAppendChild moves the node out of
-            // the nodeList and into the new tree
-            while (parser.nodeListItem(children, 0)) |child| {
+            const ln = try parser.nodeListLength(children);
+            for (0..ln) |_| {
+                // always index 0, because nodeAppendChild moves the node out of
+                // the nodeList and into the new tree
+                const child = try parser.nodeListItem(children, 0) orelse continue;
                 _ = try parser.nodeAppendChild(node, child);
             }
         }
 
         {
             const children = try parser.nodeGetChildNodes(body);
-            // always index 0, because nodeAppendChild moves the node out of
-            // the nodeList and into the new tree
-            while (parser.nodeListItem(children, 0)) |child| {
+            const ln = try parser.nodeListLength(children);
+            for (0..ln) |_| {
+                // always index 0, because nodeAppendChild moves the node out of
+                // the nodeList and into the new tree
+                const child = try parser.nodeListItem(children, 0) orelse continue;
                 _ = try parser.nodeAppendChild(node, child);
             }
         }
     }
 
-    /// Parses the given `input` string and inserts its children to an element at given `position`.
-    /// https://developer.mozilla.org/en-US/docs/Web/API/Element/insertAdjacentHTML
-    ///
-    /// TODO: Support for XML parsing and `TrustedHTML` instances.
-    pub fn _insertAdjacentHTML(self: *parser.Element, position: []const u8, input: []const u8) !void {
-        const self_node = parser.elementToNode(self);
-        const doc = parser.nodeOwnerDocument(self_node) orelse {
-            return parser.DOMError.WrongDocument;
-        };
-
-        // Parse the fragment.
-        // Should return error.Syntax on fail?
-        const fragment = try parser.documentParseFragmentFromStr(doc, input);
-        const fragment_node = parser.documentFragmentToNode(fragment);
-
-        // We always get it wrapped like so:
-        // <html><head></head><body>{ ... }</body></html>
-        // None of the following can be null.
-        const maybe_html = parser.nodeFirstChild(fragment_node);
-        std.debug.assert(maybe_html != null);
-        const html = maybe_html orelse return;
-
-        const maybe_body = parser.nodeLastChild(html);
-        std.debug.assert(maybe_body != null);
-        const body = maybe_body orelse return;
-
-        const children = try parser.nodeGetChildNodes(body);
-
-        // * `target_node` is `*Node` (where we actually insert),
-        // * `prev_node` is `?*Node`.
-        const target_node, const prev_node = blk: {
-            // Prefer case-sensitive match.
-            // "beforeend" was the most common case in my tests; we might adjust the order
-            // depending on which ones websites prefer most.
-            if (std.mem.eql(u8, position, "beforeend")) {
-                break :blk .{ self_node, null };
-            }
-
-            if (std.mem.eql(u8, position, "afterbegin")) {
-                // Get the first child; null indicates there are no children.
-                const first_child = parser.nodeFirstChild(self_node);
-                break :blk .{ self_node, first_child };
-            }
-
-            if (std.mem.eql(u8, position, "beforebegin")) {
-                // The node must have a parent node in order to use this variant.
-                const parent = parser.nodeParentNode(self_node) orelse return error.NoModificationAllowed;
-                // Parent cannot be Document.
-                // Should have checks for document_fragment and document_type?
-                if (parser.nodeType(parent) == .document) {
-                    return error.NoModificationAllowed;
-                }
-
-                break :blk .{ parent, self_node };
-            }
-
-            if (std.mem.eql(u8, position, "afterend")) {
-                // The node must have a parent node in order to use this variant.
-                const parent = parser.nodeParentNode(self_node) orelse return error.NoModificationAllowed;
-                // Parent cannot be Document.
-                if (parser.nodeType(parent) == .document) {
-                    return error.NoModificationAllowed;
-                }
-                // Get the next sibling or null; null indicates our node is the only one.
-                const sibling = parser.nodeNextSibling(self_node);
-                break :blk .{ parent, sibling };
-            }
-
-            // Thrown if:
-            // * position is not one of the four listed values.
-            // * The input is XML that is not well-formed.
-            return error.Syntax;
-        };
-
-        while (parser.nodeListItem(children, 0)) |child| {
-            _ = try parser.nodeInsertBefore(target_node, child, prev_node);
-        }
-    }
-
     // The closest() method of the Element interface traverses the element and its parents (heading toward the document root) until it finds a node that matches the specified CSS selector.
     // Returns the closest ancestor Element or itself, which matches the selectors. If there are no such element, null.
     pub fn _closest(self: *parser.Element, selector: []const u8, page: *Page) !?*parser.Element {
@@ -319,7 +234,7 @@ pub const Element = struct {
                 }
                 return parser.nodeToElement(current.node);
             }
-            current = current.parent() orelse return null;
+            current = try current.parent() orelse return null;
         }
     }
 
@@ -435,18 +350,28 @@ pub const Element = struct {
         return try parser.elementRemoveAttributeNode(self, attr);
     }
 
-    pub fn _getElementsByTagName(self: *parser.Element, tag_name: js.String) !collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(
+    pub fn _getElementsByTagName(
+        self: *parser.Element,
+        tag_name: []const u8,
+        page: *Page,
+    ) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(
+            page.arena,
             parser.elementToNode(self),
-            tag_name.string,
+            tag_name,
             .{ .include_root = false },
         );
     }
 
-    pub fn _getElementsByClassName(self: *parser.Element, class_names: js.String) !collection.HTMLCollection {
+    pub fn _getElementsByClassName(
+        self: *parser.Element,
+        classNames: []const u8,
+        page: *Page,
+    ) !collection.HTMLCollection {
         return try collection.HTMLCollectionByClassName(
+            page.arena,
             parser.elementToNode(self),
-            class_names.string,
+            classNames,
             .{ .include_root = false },
         );
     }
@@ -482,13 +407,13 @@ pub const Element = struct {
     // NonDocumentTypeChildNode
     // https://dom.spec.whatwg.org/#interface-nondocumenttypechildnode
     pub fn get_previousElementSibling(self: *parser.Element) !?Union {
-        const res = parser.nodePreviousElementSibling(parser.elementToNode(self));
+        const res = try parser.nodePreviousElementSibling(parser.elementToNode(self));
         if (res == null) return null;
         return try toInterface(res.?);
     }
 
     pub fn get_nextElementSibling(self: *parser.Element) !?Union {
-        const res = parser.nodeNextElementSibling(parser.elementToNode(self));
+        const res = try parser.nodeNextElementSibling(parser.elementToNode(self));
         if (res == null) return null;
         return try toInterface(res.?);
     }
@@ -501,7 +426,7 @@ pub const Element = struct {
         while (true) {
             next = try walker.get_next(root, next) orelse return null;
             // ignore non-element nodes.
-            if (parser.nodeType(next.?) != .element) {
+            if (try parser.nodeType(next.?) != .element) {
                 continue;
             }
             const e = parser.nodeToElement(next.?);
@@ -549,7 +474,7 @@ pub const Element = struct {
     // Returns a 0 DOMRect object if the element is eventually detached from the main window
     pub fn _getBoundingClientRect(self: *parser.Element, page: *Page) !DOMRect {
         // Since we are lazy rendering we need to do this check. We could store the renderer in a viewport such that it could cache these, but it would require tracking changes.
-        if (!page.isNodeAttached(parser.elementToNode(self))) {
+        if (!try page.isNodeAttached(parser.elementToNode(self))) {
             return DOMRect{
                 .x = 0,
                 .y = 0,
@@ -568,7 +493,7 @@ pub const Element = struct {
     // We do not render so it only always return the element's bounding rect.
     // Returns an empty array if the element is eventually detached from the main window
     pub fn _getClientRects(self: *parser.Element, page: *Page) ![]DOMRect {
-        if (!page.isNodeAttached(parser.elementToNode(self))) {
+        if (!try page.isNodeAttached(parser.elementToNode(self))) {
             return &.{};
         }
         const heap_ptr = try page.call_arena.create(DOMRect);
@@ -599,8 +524,6 @@ pub const Element = struct {
         contentVisibilityAuto: bool,
         opacityProperty: bool,
         visibilityProperty: bool,
-        checkVisibilityCSS: bool,
-        checkOpacity: bool,
     };
 
     pub fn _checkVisibility(self: *parser.Element, opts: ?CheckVisibilityOpts) bool {
@@ -626,7 +549,7 @@ pub const Element = struct {
         }
 
         // Not sure what to do if there is no owner document
-        const doc = parser.nodeOwnerDocument(@ptrCast(self)) orelse return error.InvalidArgument;
+        const doc = try parser.nodeOwnerDocument(@ptrCast(self)) orelse return error.InvalidArgument;
         const fragment = try parser.documentCreateDocumentFragment(doc);
         const sr = try page.arena.create(ShadowRoot);
         sr.* = .{
@@ -660,7 +583,7 @@ pub const Element = struct {
         return sr;
     }
 
-    pub fn _animate(self: *parser.Element, effect: js.Object, opts: js.Object) !Animation {
+    pub fn _animate(self: *parser.Element, effect: JsObject, opts: JsObject) !Animation {
         _ = self;
         _ = opts;
         return Animation.constructor(effect, null);
@@ -672,7 +595,7 @@ pub const Element = struct {
         // for related elements JIT by walking the tree, but there could be
         // cases in libdom or the Zig WebAPI where this reference is kept
         const as_node: *parser.Node = @ptrCast(self);
-        const parent = parser.nodeParentNode(as_node) orelse return;
+        const parent = try parser.nodeParentNode(as_node) orelse return;
         _ = try Node._removeChild(parent, as_node);
     }
 };

src/browser/dom/event_target.zig

@@ -17,6 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const Env = @import("../env.zig").Env;
 const parser = @import("../netsurf.zig");
 const Page = @import("../page.zig").Page;
 
@@ -34,7 +35,6 @@ pub const Union = union(enum) {
     screen_orientation: *@import("../html/screen.zig").ScreenOrientation,
     performance: *@import("performance.zig").Performance,
     media_query_list: *@import("../html/media_query_list.zig").MediaQueryList,
-    navigation: *@import("../navigation/Navigation.zig"),
 };
 
 // EventTarget implementation
@@ -48,7 +48,7 @@ pub const EventTarget = struct {
     pub fn toInterface(et: *parser.EventTarget, page: *Page) !Union {
         // libdom assumes that all event targets are libdom nodes. They are not.
 
-        switch (parser.eventTargetInternalType(et)) {
+        switch (try parser.eventTargetInternalType(et)) {
             .libdom_node => {
                 return .{ .node = try nod.Node.toInterface(@as(*parser.Node, @ptrCast(et))) };
             },
@@ -83,11 +83,6 @@ pub const EventTarget = struct {
             .media_query_list => {
                 return .{ .media_query_list = @fieldParentPtr("base", @as(*parser.EventTargetTBase, @ptrCast(et))) };
             },
-            .navigation => {
-                const NavigationEventTarget = @import("../navigation/NavigationEventTarget.zig");
-                const base: *NavigationEventTarget = @fieldParentPtr("base", @as(*parser.EventTargetTBase, @ptrCast(et)));
-                return .{ .navigation = @fieldParentPtr("proto", base) };
-            },
         }
     }
 
@@ -106,9 +101,6 @@ pub const EventTarget = struct {
         page: *Page,
     ) !void {
         _ = try EventHandler.register(page.arena, self, typ, listener, opts);
-        if (std.mem.eql(u8, typ, "slotchange")) {
-            try page.registerSlotChangeMonitor();
-        }
     }
 
     const RemoveEventListenerOpts = union(enum) {

src/browser/dom/html_collection.zig

@@ -23,6 +23,7 @@ const parser = @import("../netsurf.zig");
 
 const Element = @import("element.zig").Element;
 const Union = @import("element.zig").Union;
+const JsThis = @import("../env.zig").JsThis;
 const Walker = @import("walker.zig").Walker;
 
 const Matcher = union(enum) {
@@ -51,13 +52,13 @@ pub const MatchByTagName = struct {
     tag: []const u8,
     is_wildcard: bool,
 
-    fn init(tag_name: []const u8) MatchByTagName {
+    fn init(arena: Allocator, tag_name: []const u8) !MatchByTagName {
         if (std.mem.eql(u8, tag_name, "*")) {
             return .{ .tag = "*", .is_wildcard = true };
         }
 
         return .{
-            .tag = tag_name,
+            .tag = try arena.dupe(u8, tag_name),
             .is_wildcard = false,
         };
     }
@@ -68,14 +69,15 @@ pub const MatchByTagName = struct {
 };
 
 pub fn HTMLCollectionByTagName(
+    arena: Allocator,
     root: ?*parser.Node,
     tag_name: []const u8,
     opts: Opts,
-) HTMLCollection {
-    return .{
+) !HTMLCollection {
+    return HTMLCollection{
         .root = root,
         .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchByTagName = MatchByTagName.init(tag_name) },
+        .matcher = .{ .matchByTagName = try MatchByTagName.init(arena, tag_name) },
         .mutable = opts.mutable,
         .include_root = opts.include_root,
     };
@@ -84,9 +86,9 @@ pub fn HTMLCollectionByTagName(
 pub const MatchByClassName = struct {
     class_names: []const u8,
 
-    fn init(class_names: []const u8) !MatchByClassName {
+    fn init(arena: Allocator, class_names: []const u8) !MatchByClassName {
         return .{
-            .class_names = class_names,
+            .class_names = try arena.dupe(u8, class_names),
         };
     }
 
@@ -105,14 +107,15 @@ pub const MatchByClassName = struct {
 };
 
 pub fn HTMLCollectionByClassName(
+    arena: Allocator,
     root: ?*parser.Node,
-    class_names: []const u8,
+    classNames: []const u8,
     opts: Opts,
 ) !HTMLCollection {
     return HTMLCollection{
         .root = root,
         .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchByClassName = try MatchByClassName.init(class_names) },
+        .matcher = .{ .matchByClassName = try MatchByClassName.init(arena, classNames) },
         .mutable = opts.mutable,
         .include_root = opts.include_root,
     };
@@ -121,8 +124,10 @@ pub fn HTMLCollectionByClassName(
 pub const MatchByName = struct {
     name: []const u8,
 
-    fn init(name: []const u8) !MatchByName {
-        return .{ .name = name };
+    fn init(arena: Allocator, name: []const u8) !MatchByName {
+        return .{
+            .name = try arena.dupe(u8, name),
+        };
     }
 
     pub fn match(self: MatchByName, node: *parser.Node) !bool {
@@ -133,6 +138,7 @@ pub const MatchByName = struct {
 };
 
 pub fn HTMLCollectionByName(
+    arena: Allocator,
     root: ?*parser.Node,
     name: []const u8,
     opts: Opts,
@@ -140,7 +146,7 @@ pub fn HTMLCollectionByName(
     return HTMLCollection{
         .root = root,
         .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchByName = try MatchByName.init(name) },
+        .matcher = .{ .matchByName = try MatchByName.init(arena, name) },
         .mutable = opts.mutable,
         .include_root = opts.include_root,
     };
@@ -197,8 +203,8 @@ pub fn HTMLCollectionChildren(
     };
 }
 
-pub fn HTMLCollectionEmpty() HTMLCollection {
-    return .{
+pub fn HTMLCollectionEmpty() !HTMLCollection {
+    return HTMLCollection{
         .root = null,
         .walker = .{ .walkerNone = .{} },
         .matcher = .{ .matchFalse = .{} },
@@ -220,11 +226,14 @@ pub const MatchByLinks = struct {
     }
 };
 
-pub fn HTMLCollectionByLinks(root: ?*parser.Node, opts: Opts) HTMLCollection {
-    return .{
+pub fn HTMLCollectionByLinks(
+    root: ?*parser.Node,
+    opts: Opts,
+) !HTMLCollection {
+    return HTMLCollection{
         .root = root,
         .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchByLinks = .{} },
+        .matcher = .{ .matchByLinks = MatchByLinks{} },
         .mutable = opts.mutable,
         .include_root = opts.include_root,
     };
@@ -243,11 +252,14 @@ pub const MatchByAnchors = struct {
     }
 };
 
-pub fn HTMLCollectionByAnchors(root: ?*parser.Node, opts: Opts) HTMLCollection {
-    return .{
+pub fn HTMLCollectionByAnchors(
+    root: ?*parser.Node,
+    opts: Opts,
+) !HTMLCollection {
+    return HTMLCollection{
         .root = root,
         .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchByAnchors = .{} },
+        .matcher = .{ .matchByAnchors = MatchByAnchors{} },
         .mutable = opts.mutable,
         .include_root = opts.include_root,
     };
@@ -286,7 +298,7 @@ const Opts = struct {
 
 // WEB IDL https://dom.spec.whatwg.org/#htmlcollection
 // HTMLCollection is re implemented in zig here because libdom
-// dom_html_collection expects a comparison function callback as argument.
+// dom_html_collection expects a comparison function callback as arguement.
 // But we wanted a dynamically comparison here, according to the match tagname.
 pub const HTMLCollection = struct {
     matcher: Matcher,
@@ -332,7 +344,7 @@ pub const HTMLCollection = struct {
         var node = try self.start() orelse return 0;
 
         while (true) {
-            if (parser.nodeType(node) == .element) {
+            if (try parser.nodeType(node) == .element) {
                 if (try self.matcher.match(node)) {
                     len += 1;
                 }
@@ -359,7 +371,7 @@ pub const HTMLCollection = struct {
         }
 
         while (true) {
-            if (parser.nodeType(node) == .element) {
+            if (try parser.nodeType(node) == .element) {
                 if (try self.matcher.match(node)) {
                     // check if we found the searched element.
                     if (i == index) {
@@ -393,7 +405,7 @@ pub const HTMLCollection = struct {
         var node = try self.start() orelse return null;
 
         while (true) {
-            if (parser.nodeType(node) == .element) {
+            if (try parser.nodeType(node) == .element) {
                 if (try self.matcher.match(node)) {
                     const elem = @as(*parser.Element, @ptrCast(node));
 
@@ -428,23 +440,24 @@ pub const HTMLCollection = struct {
         return null;
     }
 
-    pub fn indexed_get(self: *HTMLCollection, index: u32, has_value: *bool) !?Union {
-        return (try _item(self, index)) orelse {
-            has_value.* = false;
-            return undefined;
-        };
-    }
+    pub fn postAttach(self: *HTMLCollection, js_this: JsThis) !void {
+        const len = try self.get_length();
+        for (0..len) |i| {
+            const node = try self.item(@intCast(i)) orelse unreachable;
+            const e = @as(*parser.Element, @ptrCast(node));
+            const as_interface = try Element.toInterface(e);
+            try js_this.setIndex(@intCast(i), as_interface, .{});
 
-    pub fn named_get(self: *const HTMLCollection, name: []const u8, has_value: *bool) !?Union {
-        // Even though an entry might have an empty id, the spec says
-        // that namedItem("") should always return null
-        if (name.len == 0) {
-            return null;
+            if (try item_name(e)) |name| {
+                // Even though an entry might have an empty id, the spec says
+                // that namedItem("") should always return null
+                if (name.len > 0) {
+                    // Named fields should not be enumerable (it is defined with
+                    // the LegacyUnenumerableNamedProperties flag.)
+                    try js_this.set(name, as_interface, .{ .DONT_ENUM = true });
+                }
+            }
         }
-        return (try _namedItem(self, name)) orelse {
-            has_value.* = false;
-            return undefined;
-        };
     }
 };
 

src/browser/dom/intersection_observer.zig

@@ -0,0 +1,186 @@
+// Copyright (C) 2023-2025  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+
+const log = @import("../../log.zig");
+const parser = @import("../netsurf.zig");
+const Page = @import("../page.zig").Page;
+
+const Env = @import("../env.zig").Env;
+const Element = @import("element.zig").Element;
+
+pub const Interfaces = .{
+    IntersectionObserver,
+    IntersectionObserverEntry,
+};
+
+// This is supposed to listen to change between the root and observation targets.
+// However, our rendered stores everything as 1 pixel sized boxes in a long row that never changes.
+// As such, there are no changes to intersections between the root and any target.
+// Instead we keep a list of all entries that are being observed.
+// The callback is called with all entries everytime a new entry is added(observed).
+// Potentially we should also call the callback at a regular interval.
+// The returned Entries are phony, they always indicate full intersection.
+// https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver
+pub const IntersectionObserver = struct {
+    page: *Page,
+    callback: Env.Function,
+    options: IntersectionObserverOptions,
+
+    observed_entries: std.ArrayListUnmanaged(IntersectionObserverEntry),
+
+    // new IntersectionObserver(callback)
+    // new IntersectionObserver(callback, options) [not supported yet]
+    pub fn constructor(callback: Env.Function, options_: ?IntersectionObserverOptions, page: *Page) !IntersectionObserver {
+        var options = IntersectionObserverOptions{
+            .root = parser.documentToNode(parser.documentHTMLToDocument(page.window.document)),
+            .rootMargin = "0px 0px 0px 0px",
+            .threshold = .{ .single = 0.0 },
+        };
+        if (options_) |*o| {
+            if (o.root) |root| {
+                options.root = root;
+            } // Other properties are not used due to the way we render
+        }
+
+        return .{
+            .page = page,
+            .callback = callback,
+            .options = options,
+            .observed_entries = .{},
+        };
+    }
+
+    pub fn _disconnect(self: *IntersectionObserver) !void {
+        self.observed_entries = .{}; // We don't free as it is on an arena
+    }
+
+    pub fn _observe(self: *IntersectionObserver, target_element: *parser.Element) !void {
+        for (self.observed_entries.items) |*observer| {
+            if (observer.target == target_element) {
+                return; // Already observed
+            }
+        }
+
+        try self.observed_entries.append(self.page.arena, .{
+            .page = self.page,
+            .target = target_element,
+            .options = &self.options,
+        });
+
+        var result: Env.Function.Result = undefined;
+        self.callback.tryCall(void, .{self.observed_entries.items}, &result) catch {
+            log.debug(.user_script, "callback error", .{
+                .err = result.exception,
+                .stack = result.stack,
+                .source = "intersection observer",
+            });
+        };
+    }
+
+    pub fn _unobserve(self: *IntersectionObserver, target: *parser.Element) !void {
+        for (self.observed_entries.items, 0..) |*observer, index| {
+            if (observer.target == target) {
+                _ = self.observed_entries.swapRemove(index);
+                break;
+            }
+        }
+    }
+
+    pub fn _takeRecords(self: *IntersectionObserver) []IntersectionObserverEntry {
+        return self.observed_entries.items;
+    }
+};
+
+const IntersectionObserverOptions = struct {
+    root: ?*parser.Node, // Element or Document
+    rootMargin: ?[]const u8,
+    threshold: ?Threshold,
+
+    const Threshold = union(enum) {
+        single: f32,
+        list: []const f32,
+    };
+};
+
+// https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserverEntry
+// https://w3c.github.io/IntersectionObserver/#intersection-observer-entry
+pub const IntersectionObserverEntry = struct {
+    page: *Page,
+    target: *parser.Element,
+    options: *IntersectionObserverOptions,
+
+    // Returns the bounds rectangle of the target element as a DOMRectReadOnly. The bounds are computed as described in the documentation for Element.getBoundingClientRect().
+    pub fn get_boundingClientRect(self: *const IntersectionObserverEntry) !Element.DOMRect {
+        return Element._getBoundingClientRect(self.target, self.page);
+    }
+
+    // Returns the ratio of the intersectionRect to the boundingClientRect.
+    pub fn get_intersectionRatio(_: *const IntersectionObserverEntry) f32 {
+        return 1.0;
+    }
+
+    // Returns a DOMRectReadOnly representing the target's visible area.
+    pub fn get_intersectionRect(self: *const IntersectionObserverEntry) !Element.DOMRect {
+        return Element._getBoundingClientRect(self.target, self.page);
+    }
+
+    // A Boolean value which is true if the target element intersects with the
+    // intersection observer's root. If this is true, then, the
+    // IntersectionObserverEntry describes a transition into a state of
+    // intersection; if it's false, then you know the transition is from
+    // intersecting to not-intersecting.
+    pub fn get_isIntersecting(_: *const IntersectionObserverEntry) bool {
+        return true;
+    }
+
+    // Returns a DOMRectReadOnly for the intersection observer's root.
+    pub fn get_rootBounds(self: *const IntersectionObserverEntry) !Element.DOMRect {
+        const root = self.options.root.?;
+        if (@intFromPtr(root) == @intFromPtr(self.page.window.document)) {
+            return self.page.renderer.boundingRect();
+        }
+
+        const root_type = try parser.nodeType(root);
+
+        var element: *parser.Element = undefined;
+        switch (root_type) {
+            .element => element = parser.nodeToElement(root),
+            .document => {
+                const doc = parser.nodeToDocument(root);
+                element = (try parser.documentGetDocumentElement(doc)).?;
+            },
+            else => return error.InvalidState,
+        }
+
+        return Element._getBoundingClientRect(element, self.page);
+    }
+
+    // The Element whose intersection with the root changed.
+    pub fn get_target(self: *const IntersectionObserverEntry) *parser.Element {
+        return self.target;
+    }
+
+    // TODO: pub fn get_time(self: *const IntersectionObserverEntry)
+};
+
+const testing = @import("../../testing.zig");
+test "Browser: DOM.IntersectionObserver" {
+    try testing.htmlRunner("dom/intersection_observer.html");
+}

src/browser/dom/mutation_observer.zig

@@ -17,12 +17,13 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const Allocator = std.mem.Allocator;
 
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
 const Page = @import("../page.zig").Page;
 
+const Env = @import("../env.zig").Env;
 const NodeList = @import("nodelist.zig").NodeList;
 
 pub const Interfaces = .{
@@ -35,21 +36,21 @@ const Walker = @import("../dom/walker.zig").WalkerChildren;
 // WEB IDL https://dom.spec.whatwg.org/#interface-mutationobserver
 pub const MutationObserver = struct {
     page: *Page,
-    cbk: js.Function,
+    cbk: Env.Function,
+    connected: bool,
     scheduled: bool,
-    observers: std.ArrayListUnmanaged(*Observer),
 
     // List of records which were observed. When the call scope ends, we need to
     // execute our callback with it.
     observed: std.ArrayListUnmanaged(MutationRecord),
 
-    pub fn constructor(cbk: js.Function, page: *Page) !MutationObserver {
+    pub fn constructor(cbk: Env.Function, page: *Page) !MutationObserver {
         return .{
             .cbk = cbk,
             .page = page,
             .observed = .{},
+            .connected = true,
             .scheduled = false,
-            .observers = .empty,
         };
     }
 
@@ -68,17 +69,15 @@ pub const MutationObserver = struct {
             .event_node = .{ .id = self.cbk.id, .func = Observer.handle },
         };
 
-        try self.observers.append(arena, observer);
-
         // register node's events
         if (options.childList or options.subtree) {
-            observer.dom_node_inserted_listener = try parser.eventTargetAddEventListener(
+            _ = try parser.eventTargetAddEventListener(
                 parser.toEventTarget(parser.Node, node),
                 "DOMNodeInserted",
                 &observer.event_node,
                 false,
             );
-            observer.dom_node_removed_listener = try parser.eventTargetAddEventListener(
+            _ = try parser.eventTargetAddEventListener(
                 parser.toEventTarget(parser.Node, node),
                 "DOMNodeRemoved",
                 &observer.event_node,
@@ -86,7 +85,7 @@ pub const MutationObserver = struct {
             );
         }
         if (options.attr()) {
-            observer.dom_node_attribute_modified_listener = try parser.eventTargetAddEventListener(
+            _ = try parser.eventTargetAddEventListener(
                 parser.toEventTarget(parser.Node, node),
                 "DOMAttrModified",
                 &observer.event_node,
@@ -94,7 +93,7 @@ pub const MutationObserver = struct {
             );
         }
         if (options.cdata()) {
-            observer.dom_cdata_modified_listener = try parser.eventTargetAddEventListener(
+            _ = try parser.eventTargetAddEventListener(
                 parser.toEventTarget(parser.Node, node),
                 "DOMCharacterDataModified",
                 &observer.event_node,
@@ -102,7 +101,7 @@ pub const MutationObserver = struct {
             );
         }
         if (options.subtree) {
-            observer.dom_subtree_modified_listener = try parser.eventTargetAddEventListener(
+            _ = try parser.eventTargetAddEventListener(
                 parser.toEventTarget(parser.Node, node),
                 "DOMSubtreeModified",
                 &observer.event_node,
@@ -113,6 +112,10 @@ pub const MutationObserver = struct {
 
     fn callback(ctx: *anyopaque) ?u32 {
         const self: *MutationObserver = @ptrCast(@alignCast(ctx));
+        if (self.connected == false) {
+            self.scheduled = true;
+            return null;
+        }
         self.scheduled = false;
 
         const records = self.observed.items;
@@ -122,8 +125,8 @@ pub const MutationObserver = struct {
 
         defer self.observed.clearRetainingCapacity();
 
-        var result: js.Function.Result = undefined;
-        self.cbk.tryCallWithThis(void, self, .{records}, &result) catch {
+        var result: Env.Function.Result = undefined;
+        self.cbk.tryCall(void, .{records}, &result) catch {
             log.debug(.user_script, "callback error", .{
                 .err = result.exception,
                 .stack = result.stack,
@@ -133,55 +136,9 @@ pub const MutationObserver = struct {
         return null;
     }
 
+    // TODO
     pub fn _disconnect(self: *MutationObserver) !void {
-        for (self.observers.items) |observer| {
-            const event_target = parser.toEventTarget(parser.Node, observer.node);
-            if (observer.dom_node_inserted_listener) |listener| {
-                try parser.eventTargetRemoveEventListener(
-                    event_target,
-                    "DOMNodeInserted",
-                    listener,
-                    false,
-                );
-            }
-
-            if (observer.dom_node_removed_listener) |listener| {
-                try parser.eventTargetRemoveEventListener(
-                    event_target,
-                    "DOMNodeRemoved",
-                    listener,
-                    false,
-                );
-            }
-
-            if (observer.dom_node_attribute_modified_listener) |listener| {
-                try parser.eventTargetRemoveEventListener(
-                    event_target,
-                    "DOMAttrModified",
-                    listener,
-                    false,
-                );
-            }
-
-            if (observer.dom_cdata_modified_listener) |listener| {
-                try parser.eventTargetRemoveEventListener(
-                    event_target,
-                    "DOMCharacterDataModified",
-                    listener,
-                    false,
-                );
-            }
-
-            if (observer.dom_subtree_modified_listener) |listener| {
-                try parser.eventTargetRemoveEventListener(
-                    event_target,
-                    "DOMSubtreeModified",
-                    listener,
-                    false,
-                );
-            }
-        }
-        self.observers.clearRetainingCapacity();
+        self.connected = false;
     }
 
     // TODO
@@ -266,12 +223,6 @@ const Observer = struct {
 
     event_node: parser.EventNode,
 
-    dom_node_inserted_listener: ?*parser.EventListener = null,
-    dom_node_removed_listener: ?*parser.EventListener = null,
-    dom_node_attribute_modified_listener: ?*parser.EventListener = null,
-    dom_cdata_modified_listener: ?*parser.EventListener = null,
-    dom_subtree_modified_listener: ?*parser.EventListener = null,
-
     fn appliesTo(
         self: *const Observer,
         target: *parser.Node,
@@ -333,7 +284,7 @@ const Observer = struct {
 
         const mutation_event = parser.eventToMutationEvent(event);
         const event_type = blk: {
-            const t = parser.eventType(event);
+            const t = try parser.eventType(event);
             break :blk std.meta.stringToEnum(MutationEventType, t) orelse return;
         };
 
@@ -351,12 +302,12 @@ const Observer = struct {
             .DOMAttrModified => {
                 record.attribute_name = parser.mutationEventAttributeName(mutation_event) catch null;
                 if (self.options.attributeOldValue) {
-                    record.old_value = parser.mutationEventPrevValue(mutation_event);
+                    record.old_value = parser.mutationEventPrevValue(mutation_event) catch null;
                 }
             },
             .DOMCharacterDataModified => {
                 if (self.options.characterDataOldValue) {
-                    record.old_value = parser.mutationEventPrevValue(mutation_event);
+                    record.old_value = parser.mutationEventPrevValue(mutation_event) catch null;
                 }
             },
             .DOMNodeInserted => {

src/browser/dom/node.zig

@@ -20,7 +20,7 @@ const std = @import("std");
 
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
-const generate = @import("../js/generate.zig");
+const generate = @import("../../runtime/generate.zig");
 
 const Page = @import("../page.zig").Page;
 const EventTarget = @import("event_target.zig").EventTarget;
@@ -67,7 +67,7 @@ pub const Node = struct {
     pub const subtype = .node;
 
     pub fn toInterface(node: *parser.Node) !Union {
-        return switch (parser.nodeType(node)) {
+        return switch (try parser.nodeType(node)) {
             .element => try Element.toInterfaceT(
                 Union,
                 @as(*parser.Element, @ptrCast(node)),
@@ -124,7 +124,7 @@ pub const Node = struct {
     }
 
     pub fn get_firstChild(self: *parser.Node) !?Union {
-        const res = parser.nodeFirstChild(self);
+        const res = try parser.nodeFirstChild(self);
         if (res == null) {
             return null;
         }
@@ -132,7 +132,7 @@ pub const Node = struct {
     }
 
     pub fn get_lastChild(self: *parser.Node) !?Union {
-        const res = parser.nodeLastChild(self);
+        const res = try parser.nodeLastChild(self);
         if (res == null) {
             return null;
         }
@@ -140,7 +140,7 @@ pub const Node = struct {
     }
 
     pub fn get_nextSibling(self: *parser.Node) !?Union {
-        const res = parser.nodeNextSibling(self);
+        const res = try parser.nodeNextSibling(self);
         if (res == null) {
             return null;
         }
@@ -148,7 +148,7 @@ pub const Node = struct {
     }
 
     pub fn get_previousSibling(self: *parser.Node) !?Union {
-        const res = parser.nodePreviousSibling(self);
+        const res = try parser.nodePreviousSibling(self);
         if (res == null) {
             return null;
         }
@@ -156,7 +156,7 @@ pub const Node = struct {
     }
 
     pub fn get_parentNode(self: *parser.Node) !?Union {
-        const res = parser.nodeParentNode(self);
+        const res = try parser.nodeParentNode(self);
         if (res == null) {
             return null;
         }
@@ -164,7 +164,7 @@ pub const Node = struct {
     }
 
     pub fn get_parentElement(self: *parser.Node) !?ElementUnion {
-        const res = parser.nodeParentElement(self);
+        const res = try parser.nodeParentElement(self);
         if (res == null) {
             return null;
         }
@@ -176,11 +176,11 @@ pub const Node = struct {
     }
 
     pub fn get_nodeType(self: *parser.Node) !u8 {
-        return @intFromEnum(parser.nodeType(self));
+        return @intFromEnum(try parser.nodeType(self));
     }
 
     pub fn get_ownerDocument(self: *parser.Node) !?*parser.DocumentHTML {
-        const res = parser.nodeOwnerDocument(self);
+        const res = try parser.nodeOwnerDocument(self);
         if (res == null) {
             return null;
         }
@@ -190,12 +190,12 @@ pub const Node = struct {
     pub fn get_isConnected(self: *parser.Node) !bool {
         var node = self;
         while (true) {
-            const node_type = parser.nodeType(node);
+            const node_type = try parser.nodeType(node);
             if (node_type == .document) {
                 return true;
             }
 
-            if (parser.nodeParentNode(node)) |parent| {
+            if (try parser.nodeParentNode(node)) |parent| {
                 // didn't find a document, but node has a parent, let's see
                 // if it's connected;
                 node = parent;
@@ -222,15 +222,15 @@ pub const Node = struct {
     // Read/Write attributes
 
     pub fn get_nodeValue(self: *parser.Node) !?[]const u8 {
-        return parser.nodeValue(self);
+        return try parser.nodeValue(self);
     }
 
     pub fn set_nodeValue(self: *parser.Node, data: []u8) !void {
         try parser.nodeSetValue(self, data);
     }
 
-    pub fn get_textContent(self: *parser.Node) ?[]const u8 {
-        return parser.nodeTextContent(self);
+    pub fn get_textContent(self: *parser.Node) !?[]const u8 {
+        return try parser.nodeTextContent(self);
     }
 
     pub fn set_textContent(self: *parser.Node, data: []u8) !void {
@@ -240,8 +240,8 @@ pub const Node = struct {
     // Methods
 
     pub fn _appendChild(self: *parser.Node, child: *parser.Node) !Union {
-        const self_owner = parser.nodeOwnerDocument(self);
-        const child_owner = parser.nodeOwnerDocument(child);
+        const self_owner = try parser.nodeOwnerDocument(self);
+        const child_owner = try parser.nodeOwnerDocument(child);
 
         // If the node to be inserted has a different ownerDocument than the parent node,
         // modern browsers automatically adopt the node and its descendants into
@@ -272,14 +272,14 @@ pub const Node = struct {
             return 0;
         }
 
-        const docself = parser.nodeOwnerDocument(self) orelse blk: {
-            if (parser.nodeType(self) == .document) {
+        const docself = try parser.nodeOwnerDocument(self) orelse blk: {
+            if (try parser.nodeType(self) == .document) {
                 break :blk @as(*parser.Document, @ptrCast(self));
             }
             break :blk null;
         };
-        const docother = parser.nodeOwnerDocument(other) orelse blk: {
-            if (parser.nodeType(other) == .document) {
+        const docother = try parser.nodeOwnerDocument(other) orelse blk: {
+            if (try parser.nodeType(other) == .document) {
                 break :blk @as(*parser.Document, @ptrCast(other));
             }
             break :blk null;
@@ -299,8 +299,8 @@ pub const Node = struct {
                 @intFromEnum(parser.DocumentPosition.contained_by);
         }
 
-        const rootself = parser.nodeGetRootNode(self);
-        const rootother = parser.nodeGetRootNode(other);
+        const rootself = try parser.nodeGetRootNode(self);
+        const rootother = try parser.nodeGetRootNode(other);
         if (rootself != rootother) {
             return @intFromEnum(parser.DocumentPosition.disconnected) +
                 @intFromEnum(parser.DocumentPosition.implementation_specific) +
@@ -347,8 +347,8 @@ pub const Node = struct {
         return 0;
     }
 
-    pub fn _contains(self: *parser.Node, other: *parser.Node) bool {
-        return parser.nodeContains(self, other);
+    pub fn _contains(self: *parser.Node, other: *parser.Node) !bool {
+        return try parser.nodeContains(self, other);
     }
 
     // Returns itself or ancestor object inheriting from Node.
@@ -360,44 +360,32 @@ pub const Node = struct {
         node: Union,
     };
     pub fn _getRootNode(self: *parser.Node, options: ?struct { composed: bool = false }, page: *Page) !GetRootNodeResult {
-        const composed = if (options) |opts| opts.composed else false;
+        if (options) |options_| if (options_.composed) {
+            log.warn(.web_api, "not implemented", .{ .feature = "getRootNode composed" });
+        };
 
-        var current_root = parser.nodeGetRootNode(self);
-
-        while (true) {
-            const node_type = parser.nodeType(current_root);
-
-            if (node_type == .document_fragment) {
-                if (parser.documentFragmentGetHost(@ptrCast(current_root))) |host| {
-                    if (page.getNodeState(host)) |state| {
-                        if (state.shadow_root) |sr| {
-                            if (!composed) {
-                                return .{ .shadow_root = sr };
-                            }
-                            current_root = parser.nodeGetRootNode(@ptrCast(sr.host));
-                            continue;
-                        }
-                    }
-                }
+        const root = try parser.nodeGetRootNode(self);
+        if (page.getNodeState(root)) |state| {
+            if (state.shadow_root) |sr| {
+                return .{ .shadow_root = sr };
             }
-            break;
         }
 
-        return .{ .node = try Node.toInterface(current_root) };
+        return .{ .node = try Node.toInterface(root) };
     }
 
-    pub fn _hasChildNodes(self: *parser.Node) bool {
-        return parser.nodeHasChildNodes(self);
+    pub fn _hasChildNodes(self: *parser.Node) !bool {
+        return try parser.nodeHasChildNodes(self);
     }
 
     pub fn get_childNodes(self: *parser.Node, page: *Page) !NodeList {
         const allocator = page.arena;
         var list: NodeList = .{};
 
-        var n = parser.nodeFirstChild(self) orelse return list;
+        var n = try parser.nodeFirstChild(self) orelse return list;
         while (true) {
             try list.append(allocator, n);
-            n = parser.nodeNextSibling(n) orelse return list;
+            n = try parser.nodeNextSibling(n) orelse return list;
         }
     }
 
@@ -406,8 +394,8 @@ pub const Node = struct {
             return _appendChild(self, new_node);
         }
 
-        const self_owner = parser.nodeOwnerDocument(self);
-        const new_node_owner = parser.nodeOwnerDocument(new_node);
+        const self_owner = try parser.nodeOwnerDocument(self);
+        const new_node_owner = try parser.nodeOwnerDocument(new_node);
 
         // If the node to be inserted has a different ownerDocument than the parent node,
         // modern browsers automatically adopt the node and its descendants into
@@ -427,7 +415,7 @@ pub const Node = struct {
     }
 
     pub fn _isDefaultNamespace(self: *parser.Node, namespace: ?[]const u8) !bool {
-        return parser.nodeIsDefaultNamespace(self, namespace);
+        return try parser.nodeIsDefaultNamespace(self, namespace);
     }
 
     pub fn _isEqualNode(self: *parser.Node, other: *parser.Node) !bool {
@@ -435,10 +423,10 @@ pub const Node = struct {
         return try parser.nodeIsEqualNode(self, other);
     }
 
-    pub fn _isSameNode(self: *parser.Node, other: *parser.Node) bool {
+    pub fn _isSameNode(self: *parser.Node, other: *parser.Node) !bool {
         // TODO: other is not an optional parameter, but can be null.
         // NOTE: there is no need to use isSameNode(); instead use the === strict equality operator
-        return parser.nodeIsSameNode(self, other);
+        return try parser.nodeIsSameNode(self, other);
     }
 
     pub fn _lookupPrefix(self: *parser.Node, namespace: ?[]const u8) !?[]const u8 {
@@ -473,7 +461,7 @@ pub const Node = struct {
 
     // Check if the hierarchy node tree constraints are respected.
     // For now, it checks only if new nodes are not self.
-    // TODO implements the others constraints.
+    // TODO implements the others contraints.
     // see https://dom.spec.whatwg.org/#concept-node-tree
     pub fn hierarchy(self: *parser.Node, nodes: []const NodeOrText) bool {
         for (nodes) |n| {
@@ -494,9 +482,9 @@ pub const Node = struct {
             return parser.DOMError.HierarchyRequest;
         }
 
-        const doc = (parser.nodeOwnerDocument(self)) orelse return;
+        const doc = (try parser.nodeOwnerDocument(self)) orelse return;
 
-        if (parser.nodeFirstChild(self)) |first| {
+        if (try parser.nodeFirstChild(self)) |first| {
             for (nodes) |node| {
                 _ = try parser.nodeInsertBefore(self, try node.toNode(doc), first);
             }
@@ -518,7 +506,7 @@ pub const Node = struct {
             return parser.DOMError.HierarchyRequest;
         }
 
-        const doc = (parser.nodeOwnerDocument(self)) orelse return;
+        const doc = (try parser.nodeOwnerDocument(self)) orelse return;
         for (nodes) |node| {
             _ = try parser.nodeAppendChild(self, try node.toNode(doc));
         }
@@ -537,7 +525,7 @@ pub const Node = struct {
         // remove existing children
         try removeChildren(self);
 
-        const doc = (parser.nodeOwnerDocument(self)) orelse return;
+        const doc = (try parser.nodeOwnerDocument(self)) orelse return;
         // add new children
         for (nodes) |node| {
             _ = try parser.nodeAppendChild(self, try node.toNode(doc));
@@ -545,30 +533,30 @@ pub const Node = struct {
     }
 
     pub fn removeChildren(self: *parser.Node) !void {
-        if (!parser.nodeHasChildNodes(self)) return;
+        if (!try parser.nodeHasChildNodes(self)) return;
 
         const children = try parser.nodeGetChildNodes(self);
-        const ln = parser.nodeListLength(children);
+        const ln = try parser.nodeListLength(children);
         var i: u32 = 0;
         while (i < ln) {
             defer i += 1;
             // we always retrieve the 0 index child on purpose: libdom nodelist
             // are dynamic. So the next child to remove is always as pos 0.
-            const child = parser.nodeListItem(children, 0) orelse continue;
+            const child = try parser.nodeListItem(children, 0) orelse continue;
             _ = try parser.nodeRemoveChild(self, child);
         }
     }
 
     pub fn before(self: *parser.Node, nodes: []const NodeOrText) !void {
-        const parent = parser.nodeParentNode(self) orelse return;
-        const doc = (parser.nodeOwnerDocument(parent)) orelse return;
+        const parent = try parser.nodeParentNode(self) orelse return;
+        const doc = (try parser.nodeOwnerDocument(parent)) orelse return;
 
         var sibling: ?*parser.Node = self;
         // have to find the first sibling that isn't in nodes
         CHECK: while (sibling) |s| {
             for (nodes) |n| {
                 if (n.is(s)) {
-                    sibling = parser.nodePreviousSibling(s);
+                    sibling = try parser.nodePreviousSibling(s);
                     continue :CHECK;
                 }
             }
@@ -576,7 +564,7 @@ pub const Node = struct {
         }
 
         if (sibling == null) {
-            sibling = parser.nodeFirstChild(parent);
+            sibling = try parser.nodeFirstChild(parent);
         }
 
         if (sibling) |ref_node| {
@@ -590,15 +578,15 @@ pub const Node = struct {
     }
 
     pub fn after(self: *parser.Node, nodes: []const NodeOrText) !void {
-        const parent = parser.nodeParentNode(self) orelse return;
-        const doc = (parser.nodeOwnerDocument(parent)) orelse return;
+        const parent = try parser.nodeParentNode(self) orelse return;
+        const doc = (try parser.nodeOwnerDocument(parent)) orelse return;
 
         // have to find the first sibling that isn't in nodes
-        var sibling = parser.nodeNextSibling(self);
+        var sibling = try parser.nodeNextSibling(self);
         CHECK: while (sibling) |s| {
             for (nodes) |n| {
                 if (n.is(s)) {
-                    sibling = parser.nodeNextSibling(s);
+                    sibling = try parser.nodeNextSibling(s);
                     continue :CHECK;
                 }
             }

src/browser/dom/node_filter.zig

@@ -17,8 +17,8 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
+const Env = @import("../env.zig").Env;
 const Node = @import("node.zig").Node;
 
 pub const NodeFilter = struct {
@@ -43,13 +43,10 @@ pub const NodeFilter = struct {
 
 const VerifyResult = enum { accept, skip, reject };
 
-pub fn verify(what_to_show: u32, filter: ?js.Function, node: *parser.Node) !VerifyResult {
-    const node_type = parser.nodeType(node);
+pub fn verify(what_to_show: u32, filter: ?Env.Function, node: *parser.Node) !VerifyResult {
+    const node_type = try parser.nodeType(node);
 
     // Verify that we can show this node type.
-    // Per the DOM spec, what_to_show filters which nodes to return, but should
-    // still traverse children. So we return .skip (not .reject) when the node
-    // type doesn't match.
     if (!switch (node_type) {
         .attribute => what_to_show & NodeFilter._SHOW_ATTRIBUTE != 0,
         .cdata_section => what_to_show & NodeFilter._SHOW_CDATA_SECTION != 0,
@@ -63,7 +60,7 @@ pub fn verify(what_to_show: u32, filter: ?js.Function, node: *parser.Node) !Veri
         .notation => what_to_show & NodeFilter._SHOW_NOTATION != 0,
         .processing_instruction => what_to_show & NodeFilter._SHOW_PROCESSING_INSTRUCTION != 0,
         .text => what_to_show & NodeFilter._SHOW_TEXT != 0,
-    }) return .skip;
+    }) return .reject;
 
     // Verify that we aren't filtering it out.
     if (filter) |f| {

src/browser/dom/node_iterator.zig

@@ -18,8 +18,8 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
+const Env = @import("../env.zig").Env;
 const NodeFilter = @import("node_filter.zig");
 const Node = @import("node.zig").Node;
 const NodeUnion = @import("node.zig").Union;
@@ -37,7 +37,7 @@ pub const NodeIterator = struct {
     reference_node: *parser.Node,
     what_to_show: u32,
     filter: ?NodeIteratorOpts,
-    filter_func: ?js.Function,
+    filter_func: ?Env.Function,
     pointer_before_current: bool = true,
     // used to track / block recursive filters
     is_in_callback: bool = false,
@@ -45,15 +45,15 @@ pub const NodeIterator = struct {
     // One of the few cases where null and undefined resolve to different default.
     // We need the raw JsObject so that we can probe the tri state:
     // null, undefined or i32.
-    pub const WhatToShow = js.Object;
+    pub const WhatToShow = Env.JsObject;
 
     pub const NodeIteratorOpts = union(enum) {
-        function: js.Function,
-        object: struct { acceptNode: js.Function },
+        function: Env.Function,
+        object: struct { acceptNode: Env.Function },
     };
 
     pub fn init(node: *parser.Node, what_to_show_: ?WhatToShow, filter: ?NodeIteratorOpts) !NodeIterator {
-        var filter_func: ?js.Function = null;
+        var filter_func: ?Env.Function = null;
         if (filter) |f| {
             filter_func = switch (f) {
                 .function => |func| func,
@@ -74,10 +74,10 @@ pub const NodeIterator = struct {
 
         return .{
             .root = node,
-            .filter = filter,
             .reference_node = node,
-            .filter_func = filter_func,
             .what_to_show = what_to_show,
+            .filter = filter,
+            .filter_func = filter_func,
         };
     }
 
@@ -115,30 +115,17 @@ pub const NodeIterator = struct {
 
         if (try self.firstChild(self.reference_node)) |child| {
             self.reference_node = child;
-            self.pointer_before_current = false;
             return try Node.toInterface(child);
         }
 
         var current = self.reference_node;
         while (current != self.root) {
-            // Try to get next sibling (including .skip/.reject nodes we need to descend into)
-            if (try self.nextSiblingOrSkipReject(current)) |result| {
-                if (result.should_descend) {
-                    // This is a .skip/.reject node - try to find acceptable children within it
-                    if (try self.firstChild(result.node)) |child| {
-                        self.reference_node = child;
-                        return try Node.toInterface(child);
-                    }
-                    // No acceptable children, continue looking at this node's siblings
-                    current = result.node;
-                    continue;
-                }
-                // This is an .accept node - return it
-                self.reference_node = result.node;
-                return try Node.toInterface(result.node);
+            if (try self.nextSibling(current)) |sibling| {
+                self.reference_node = sibling;
+                return try Node.toInterface(sibling);
             }
 
-            current = (parser.nodeParentNode(current)) orelse break;
+            current = (try parser.nodeParentNode(current)) orelse break;
         }
 
         return null;
@@ -160,7 +147,7 @@ pub const NodeIterator = struct {
         }
 
         var current = self.reference_node;
-        while (parser.nodePreviousSibling(current)) |previous| {
+        while (try parser.nodePreviousSibling(current)) |previous| {
             current = previous;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
@@ -202,11 +189,11 @@ pub const NodeIterator = struct {
 
     fn firstChild(self: *const NodeIterator, node: *parser.Node) !?*parser.Node {
         const children = try parser.nodeGetChildNodes(node);
-        const child_count = parser.nodeListLength(children);
+        const child_count = try parser.nodeListLength(children);
 
         for (0..child_count) |i| {
             const index: u32 = @intCast(i);
-            const child = (parser.nodeListItem(children, index)) orelse return null;
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, child)) {
                 .accept => return child, // NOTE: Skip and reject are equivalent for NodeIterator, this is different from TreeWalker
@@ -219,12 +206,12 @@ pub const NodeIterator = struct {
 
     fn lastChild(self: *const NodeIterator, node: *parser.Node) !?*parser.Node {
         const children = try parser.nodeGetChildNodes(node);
-        const child_count = parser.nodeListLength(children);
+        const child_count = try parser.nodeListLength(children);
 
         var index: u32 = child_count;
         while (index > 0) {
             index -= 1;
-            const child = (parser.nodeListItem(children, index)) orelse return null;
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, child)) {
                 .accept => return child, // NOTE: Skip and reject are equivalent for NodeIterator, this is different from TreeWalker
@@ -242,7 +229,7 @@ pub const NodeIterator = struct {
         var current = node;
         while (true) {
             if (current == self.root) return null;
-            current = (parser.nodeParentNode(current)) orelse return null;
+            current = (try parser.nodeParentNode(current)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
                 .accept => return current,
@@ -256,7 +243,7 @@ pub const NodeIterator = struct {
         var current = node;
 
         while (true) {
-            current = (parser.nodeNextSibling(current)) orelse return null;
+            current = (try parser.nodeNextSibling(current)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
                 .accept => return current,
@@ -267,22 +254,6 @@ pub const NodeIterator = struct {
         return null;
     }
 
-    // Get the next sibling that is either acceptable or should be descended into (skip/reject)
-    fn nextSiblingOrSkipReject(self: *const NodeIterator, node: *parser.Node) !?struct { node: *parser.Node, should_descend: bool } {
-        var current = node;
-
-        while (true) {
-            current = (parser.nodeNextSibling(current)) orelse return null;
-
-            switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
-                .accept => return .{ .node = current, .should_descend = false },
-                .skip, .reject => return .{ .node = current, .should_descend = true },
-            }
-        }
-
-        return null;
-    }
-
     fn callbackStart(self: *NodeIterator) !void {
         if (self.is_in_callback) {
             // this is the correct DOMExeption

src/browser/dom/nodelist.zig

@@ -17,12 +17,13 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const Allocator = std.mem.Allocator;
 
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
 
+const JsThis = @import("../env.zig").JsThis;
+const Function = @import("../env.zig").Function;
+
 const NodeUnion = @import("node.zig").Union;
 const Node = @import("node.zig").Node;
 
@@ -100,20 +101,13 @@ pub const NodeList = struct {
 
     nodes: NodesArrayList = .{},
 
-    pub fn deinit(self: *NodeList, allocator: Allocator) void {
-        self.nodes.deinit(allocator);
+    pub fn deinit(self: *NodeList, alloc: std.mem.Allocator) void {
+        // TODO unref all nodes
+        self.nodes.deinit(alloc);
     }
 
-    pub fn ensureTotalCapacity(self: *NodeList, allocator: Allocator, n: usize) !void {
-        return self.nodes.ensureTotalCapacity(allocator, n);
-    }
-
-    pub fn append(self: *NodeList, allocator: Allocator, node: *parser.Node) !void {
-        try self.nodes.append(allocator, node);
-    }
-
-    pub fn appendAssumeCapacity(self: *NodeList, node: *parser.Node) void {
-        self.nodes.appendAssumeCapacity(node);
+    pub fn append(self: *NodeList, alloc: std.mem.Allocator, node: *parser.Node) !void {
+        try self.nodes.append(alloc, node);
     }
 
     pub fn get_length(self: *const NodeList) u32 {
@@ -146,10 +140,10 @@ pub const NodeList = struct {
     //     };
     // }
 
-    pub fn _forEach(self: *NodeList, cbk: js.Function) !void { // TODO handle thisArg
+    pub fn _forEach(self: *NodeList, cbk: Function) !void { // TODO handle thisArg
         for (self.nodes.items, 0..) |n, i| {
             const ii: u32 = @intCast(i);
-            var result: js.Function.Result = undefined;
+            var result: Function.Result = undefined;
             cbk.tryCall(void, .{ n, ii, self }, &result) catch {
                 log.debug(.user_script, "forEach callback", .{ .err = result.exception, .stack = result.stack });
             };
@@ -173,7 +167,7 @@ pub const NodeList = struct {
     }
 
     // TODO entries() https://developer.mozilla.org/en-US/docs/Web/API/NodeList/entries
-    pub fn postAttach(self: *NodeList, js_this: js.This) !void {
+    pub fn postAttach(self: *NodeList, js_this: JsThis) !void {
         const len = self.get_length();
         for (0..len) |i| {
             const node = try self._item(@intCast(i)) orelse unreachable;

src/browser/dom/performance.zig

@@ -18,9 +18,9 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
 const EventTarget = @import("../dom/event_target.zig").EventTarget;
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 const milliTimestamp = @import("../../datetime.zig").milliTimestamp;
@@ -61,7 +61,7 @@ pub const Performance = struct {
         return milliTimestamp() - self.time_origin;
     }
 
-    pub fn _mark(_: *Performance, name: js.String, _options: ?PerformanceMark.Options, page: *Page) !PerformanceMark {
+    pub fn _mark(_: *Performance, name: []const u8, _options: ?PerformanceMark.Options, page: *Page) !PerformanceMark {
         const mark: PerformanceMark = try .constructor(name, _options, page);
         // TODO: Should store this in an entries list
         return mark;
@@ -148,14 +148,14 @@ pub const PerformanceMark = struct {
     pub const prototype = *PerformanceEntry;
 
     proto: PerformanceEntry,
-    detail: ?js.Object,
+    detail: ?Env.JsObject,
 
     const Options = struct {
-        detail: ?js.Object = null,
+        detail: ?Env.JsObject = null,
         startTime: ?f64 = null,
     };
 
-    pub fn constructor(name: js.String, _options: ?Options, page: *Page) !PerformanceMark {
+    pub fn constructor(name: []const u8, _options: ?Options, page: *Page) !PerformanceMark {
         const perf = &page.window.performance;
 
         const options = _options orelse Options{};
@@ -166,12 +166,14 @@ pub const PerformanceMark = struct {
         }
 
         const detail = if (options.detail) |d| try d.persist() else null;
-        const proto = PerformanceEntry{ .name = name.string, .entry_type = .mark, .start_time = start_time };
+
+        const duped_name = try page.arena.dupe(u8, name);
+        const proto = PerformanceEntry{ .name = duped_name, .entry_type = .mark, .start_time = start_time };
 
         return .{ .proto = proto, .detail = detail };
     }
 
-    pub fn get_detail(self: *const PerformanceMark) ?js.Object {
+    pub fn get_detail(self: *const PerformanceMark) ?Env.JsObject {
         return self.detail;
     }
 };
@@ -195,7 +197,7 @@ test "Performance: now" {
     }
 
     var after = perf._now();
-    while (after <= now) { // Loop until after > now
+    while (after <= now) { // Loop untill after > now
         try testing.expectEqual(after, now);
         after = perf._now();
     }

src/browser/dom/performance_observer.zig

@@ -17,7 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 
 const PerformanceEntry = @import("performance.zig").PerformanceEntry;
 
@@ -25,7 +25,7 @@ const PerformanceEntry = @import("performance.zig").PerformanceEntry;
 pub const PerformanceObserver = struct {
     pub const _supportedEntryTypes = [0][]const u8{};
 
-    pub fn constructor(cbk: js.Function) PerformanceObserver {
+    pub fn constructor(cbk: Env.Function) PerformanceObserver {
         _ = cbk;
         return .{};
     }

src/browser/dom/processing_instruction.zig

@@ -48,7 +48,7 @@ pub const ProcessingInstruction = struct {
     }
 
     pub fn get_data(self: *parser.ProcessingInstruction) !?[]const u8 {
-        return parser.nodeValue(parser.processingInstructionToNode(self));
+        return try parser.nodeValue(parser.processingInstructionToNode(self));
     }
 
     pub fn set_data(self: *parser.ProcessingInstruction, data: []u8) !void {
@@ -58,7 +58,7 @@ pub const ProcessingInstruction = struct {
     // netsurf's ProcessInstruction doesn't implement the dom_node_get_attributes
     // and thus will crash if we try to call nodeIsEqualNode.
     pub fn _isEqualNode(self: *parser.ProcessingInstruction, other_node: *parser.Node) !bool {
-        if (parser.nodeType(other_node) != .processing_instruction) {
+        if (try parser.nodeType(other_node) != .processing_instruction) {
             return false;
         }
 

src/browser/dom/range.zig

@@ -92,7 +92,7 @@ pub const Range = struct {
     pub fn _setStart(self: *Range, node: *parser.Node, offset_: i32) !void {
         try ensureValidOffset(node, offset_);
         const offset: u32 = @intCast(offset_);
-        const position = compare(node, offset, self.proto.end_node, self.proto.end_offset) catch |err| switch (err) {
+        const position = compare(node, offset, self.proto.start_node, self.proto.start_offset) catch |err| switch (err) {
             error.WrongDocument => blk: {
                 // allow a node with a different root than the current, or
                 // a disconnected one. Treat it as if it's "after", so that
@@ -103,7 +103,7 @@ pub const Range = struct {
         };
 
         if (position == 1) {
-            // if we're setting the node after the current end, the end must
+            // if we're setting the node after the current start, the end must
             // be set too.
             self.proto.end_offset = offset;
             self.proto.end_node = node;
@@ -176,10 +176,10 @@ pub const Range = struct {
         self.proto.end_node = node;
 
         // Set end_offset
-        switch (parser.nodeType(node)) {
+        switch (try parser.nodeType(node)) {
             .text, .cdata_section, .comment, .processing_instruction => {
                 // For text-like nodes, end_offset should be the length of the text data
-                if (parser.nodeValue(node)) |text_data| {
+                if (try parser.nodeValue(node)) |text_data| {
                     self.proto.end_offset = @intCast(text_data.len);
                 } else {
                     self.proto.end_offset = 0;
@@ -188,7 +188,7 @@ pub const Range = struct {
             else => {
                 // For element and other nodes, end_offset is the number of children
                 const child_nodes = try parser.nodeGetChildNodes(node);
-                const child_count = parser.nodeListLength(child_nodes);
+                const child_count = try parser.nodeListLength(child_nodes);
                 self.proto.end_offset = @intCast(child_count);
             },
         }
@@ -211,7 +211,7 @@ pub const Range = struct {
 
     pub fn _comparePoint(self: *const Range, node: *parser.Node, offset_: i32) !i32 {
         const start = self.proto.start_node;
-        if (parser.nodeGetRootNode(start) != parser.nodeGetRootNode(node)) {
+        if (try parser.nodeGetRootNode(start) != try parser.nodeGetRootNode(node)) {
             // WPT really wants this error to be first. Later, when we check
             // if the relative position is 'disconnected', it'll also catch this
             // case, but WPT will complain because it sometimes also sends
@@ -219,7 +219,7 @@ pub const Range = struct {
             return error.WrongDocument;
         }
 
-        if (parser.nodeType(node) == .document_type) {
+        if (try parser.nodeType(node) == .document_type) {
             return error.InvalidNodeType;
         }
 
@@ -245,8 +245,8 @@ pub const Range = struct {
     }
 
     pub fn _intersectsNode(self: *const Range, node: *parser.Node) !bool {
-        const start_root = parser.nodeGetRootNode(self.proto.start_node);
-        const node_root = parser.nodeGetRootNode(node);
+        const start_root = try parser.nodeGetRootNode(self.proto.start_node);
+        const node_root = try parser.nodeGetRootNode(node);
         if (start_root != node_root) {
             return false;
         }
@@ -299,29 +299,29 @@ fn ensureValidOffset(node: *parser.Node, offset: i32) !void {
 
 fn nodeLength(node: *parser.Node) !usize {
     switch (try isTextual(node)) {
-        true => return ((parser.nodeTextContent(node)) orelse "").len,
+        true => return ((try parser.nodeTextContent(node)) orelse "").len,
         false => {
             const children = try parser.nodeGetChildNodes(node);
-            return @intCast(parser.nodeListLength(children));
+            return @intCast(try parser.nodeListLength(children));
         },
     }
 }
 
 fn isTextual(node: *parser.Node) !bool {
-    return switch (parser.nodeType(node)) {
+    return switch (try parser.nodeType(node)) {
         .text, .comment, .cdata_section => true,
         else => false,
     };
 }
 
 fn getParentAndIndex(child: *parser.Node) !struct { *parser.Node, u32 } {
-    const parent = (parser.nodeParentNode(child)) orelse return error.InvalidNodeType;
+    const parent = (try parser.nodeParentNode(child)) orelse return error.InvalidNodeType;
     const children = try parser.nodeGetChildNodes(parent);
-    const ln = parser.nodeListLength(children);
+    const ln = try parser.nodeListLength(children);
     var i: u32 = 0;
     while (i < ln) {
         defer i += 1;
-        const c = parser.nodeListItem(children, i) orelse continue;
+        const c = try parser.nodeListItem(children, i) orelse continue;
         if (c == child) {
             return .{ parent, i };
         }
@@ -363,7 +363,7 @@ fn compare(node_a: *parser.Node, offset_a: u32, node_b: *parser.Node, offset_b:
     if (position & @intFromEnum(parser.DocumentPosition.contains) == @intFromEnum(parser.DocumentPosition.contains)) {
         // node_a contains node_b
         var child = node_b;
-        while (parser.nodeParentNode(child)) |parent| {
+        while (try parser.nodeParentNode(child)) |parent| {
             if (parent == node_a) {
                 // child.parentNode == node_a
                 break;
@@ -378,7 +378,7 @@ fn compare(node_a: *parser.Node, offset_a: u32, node_b: *parser.Node, offset_b:
 
         const child_parent, const child_index = try getParentAndIndex(child);
         std.debug.assert(node_a == child_parent);
-        return if (offset_a <= child_index) -1 else 1;
+        return if (child_index < offset_a) -1 else 1;
     }
 
     return -1;

src/browser/dom/resize_observer.zig

@@ -16,7 +16,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const parser = @import("../netsurf.zig");
 
 pub const Interfaces = .{
@@ -25,7 +25,7 @@ pub const Interfaces = .{
 
 // WEB IDL https://drafts.csswg.org/resize-observer/#resize-observer-interface
 pub const ResizeObserver = struct {
-    pub fn constructor(cbk: js.Function) ResizeObserver {
+    pub fn constructor(cbk: Env.Function) ResizeObserver {
         _ = cbk;
         return .{};
     }

src/browser/dom/shadow_root.zig

@@ -20,7 +20,7 @@ const std = @import("std");
 const dump = @import("../dump.zig");
 const parser = @import("../netsurf.zig");
 
-const js = @import(".././js/js.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 const Node = @import("node.zig").Node;
 const Element = @import("element.zig").Element;
@@ -34,7 +34,7 @@ pub const ShadowRoot = struct {
     mode: Mode,
     host: *parser.Element,
     proto: *parser.DocumentFragment,
-    adopted_style_sheets: ?js.Object = null,
+    adopted_style_sheets: ?Env.JsObject = null,
 
     pub const Mode = enum {
         open,
@@ -45,17 +45,17 @@ pub const ShadowRoot = struct {
         return Element.toInterface(self.host);
     }
 
-    pub fn get_adoptedStyleSheets(self: *ShadowRoot, page: *Page) !js.Object {
+    pub fn get_adoptedStyleSheets(self: *ShadowRoot, page: *Page) !Env.JsObject {
         if (self.adopted_style_sheets) |obj| {
             return obj;
         }
 
-        const obj = try page.js.createArray(0).persist();
+        const obj = try page.main_context.newArray(0).persist();
         self.adopted_style_sheets = obj;
         return obj;
     }
 
-    pub fn set_adoptedStyleSheets(self: *ShadowRoot, sheets: js.Object) !void {
+    pub fn set_adoptedStyleSheets(self: *ShadowRoot, sheets: Env.JsObject) !void {
         self.adopted_style_sheets = try sheets.persist();
     }
 
@@ -67,7 +67,7 @@ pub const ShadowRoot = struct {
 
     pub fn set_innerHTML(self: *ShadowRoot, str_: ?[]const u8) !void {
         const sr_doc = parser.documentFragmentToNode(self.proto);
-        const doc = parser.nodeOwnerDocument(sr_doc) orelse return parser.DOMError.WrongDocument;
+        const doc = try parser.nodeOwnerDocument(sr_doc) orelse return parser.DOMError.WrongDocument;
         try Node.removeChildren(sr_doc);
         const str = str_ orelse return;
 
@@ -80,16 +80,16 @@ pub const ShadowRoot = struct {
         // element.
         // For ShadowRoot, it appears the only the children within the body should
         // be set.
-        const html = parser.nodeFirstChild(fragment_node) orelse return;
-        const head = parser.nodeFirstChild(html) orelse return;
-        const body = parser.nodeNextSibling(head) orelse return;
+        const html = try parser.nodeFirstChild(fragment_node) orelse return;
+        const head = try parser.nodeFirstChild(html) orelse return;
+        const body = try parser.nodeNextSibling(head) orelse return;
 
         const children = try parser.nodeGetChildNodes(body);
-        const ln = parser.nodeListLength(children);
+        const ln = try parser.nodeListLength(children);
         for (0..ln) |_| {
             // always index 0, because nodeAppendChild moves the node out of
             // the nodeList and into the new tree
-            const child = parser.nodeListItem(children, 0) orelse continue;
+            const child = try parser.nodeListItem(children, 0) orelse continue;
             _ = try parser.nodeAppendChild(sr_doc, child);
         }
     }

src/browser/dom/token_list.zig

@@ -18,11 +18,12 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
 const iterator = @import("../iterator/iterator.zig");
 
+const Function = @import("../env.zig").Function;
+const JsObject = @import("../env.zig").JsObject;
 const DOMException = @import("exceptions.zig").DOMException;
 
 pub const Interfaces = .{
@@ -136,10 +137,10 @@ pub const DOMTokenList = struct {
     }
 
     // TODO handle thisArg
-    pub fn _forEach(self: *parser.TokenList, cbk: js.Function, this_arg: js.Object) !void {
+    pub fn _forEach(self: *parser.TokenList, cbk: Function, this_arg: JsObject) !void {
         var entries = _entries(self);
         while (try entries._next()) |entry| {
-            var result: js.Function.Result = undefined;
+            var result: Function.Result = undefined;
             cbk.tryCallWithThis(void, this_arg, .{ entry.@"1", entry.@"0", self }, &result) catch {
                 log.debug(.user_script, "callback error", .{
                     .err = result.exception,

src/browser/dom/tree_walker.zig

@@ -17,10 +17,11 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
 
 const NodeFilter = @import("node_filter.zig");
+const Env = @import("../env.zig").Env;
+const Page = @import("../page.zig").Page;
 const Node = @import("node.zig").Node;
 const NodeUnion = @import("node.zig").Union;
 
@@ -30,20 +31,20 @@ pub const TreeWalker = struct {
     current_node: *parser.Node,
     what_to_show: u32,
     filter: ?TreeWalkerOpts,
-    filter_func: ?js.Function,
+    filter_func: ?Env.Function,
 
     // One of the few cases where null and undefined resolve to different default.
     // We need the raw JsObject so that we can probe the tri state:
     // null, undefined or i32.
-    pub const WhatToShow = js.Object;
+    pub const WhatToShow = Env.JsObject;
 
     pub const TreeWalkerOpts = union(enum) {
-        function: js.Function,
-        object: struct { acceptNode: js.Function },
+        function: Env.Function,
+        object: struct { acceptNode: Env.Function },
     };
 
     pub fn init(node: *parser.Node, what_to_show_: ?WhatToShow, filter: ?TreeWalkerOpts) !TreeWalker {
-        var filter_func: ?js.Function = null;
+        var filter_func: ?Env.Function = null;
 
         if (filter) |f| {
             filter_func = switch (f) {
@@ -94,11 +95,11 @@ pub const TreeWalker = struct {
 
     fn firstChild(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
         const children = try parser.nodeGetChildNodes(node);
-        const child_count = parser.nodeListLength(children);
+        const child_count = try parser.nodeListLength(children);
 
         for (0..child_count) |i| {
             const index: u32 = @intCast(i);
-            const child = (parser.nodeListItem(children, index)) orelse return null;
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, child)) {
                 .accept => return child,
@@ -112,12 +113,12 @@ pub const TreeWalker = struct {
 
     fn lastChild(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
         const children = try parser.nodeGetChildNodes(node);
-        const child_count = parser.nodeListLength(children);
+        const child_count = try parser.nodeListLength(children);
 
         var index: u32 = child_count;
         while (index > 0) {
             index -= 1;
-            const child = (parser.nodeListItem(children, index)) orelse return null;
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, child)) {
                 .accept => return child,
@@ -133,7 +134,7 @@ pub const TreeWalker = struct {
         var current = node;
 
         while (true) {
-            current = (parser.nodeNextSibling(current)) orelse return null;
+            current = (try parser.nodeNextSibling(current)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
                 .accept => return current,
@@ -144,28 +145,11 @@ pub const TreeWalker = struct {
         return null;
     }
 
-    // Get the next sibling that is either acceptable or should be descended into (skip)
-    fn nextSiblingOrSkip(self: *const TreeWalker, node: *parser.Node) !?struct { node: *parser.Node, should_descend: bool } {
-        var current = node;
-
-        while (true) {
-            current = (parser.nodeNextSibling(current)) orelse return null;
-
-            switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
-                .accept => return .{ .node = current, .should_descend = false },
-                .skip => return .{ .node = current, .should_descend = true },
-                .reject => continue,
-            }
-        }
-
-        return null;
-    }
-
     fn previousSibling(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
         var current = node;
 
         while (true) {
-            current = (parser.nodePreviousSibling(current)) orelse return null;
+            current = (try parser.nodePreviousSibling(current)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
                 .accept => return current,
@@ -182,7 +166,7 @@ pub const TreeWalker = struct {
         var current = node;
         while (true) {
             if (current == self.root) return null;
-            current = (parser.nodeParentNode(current)) orelse return null;
+            current = (try parser.nodeParentNode(current)) orelse return null;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {
                 .accept => return current,
@@ -210,36 +194,19 @@ pub const TreeWalker = struct {
     }
 
     pub fn _nextNode(self: *TreeWalker) !?NodeUnion {
-        var current = self.current_node;
-
-        // First, try to go to first child of current node
-        if (try self.firstChild(current)) |child| {
+        if (try self.firstChild(self.current_node)) |child| {
             self.current_node = child;
             return try Node.toInterface(child);
         }
 
-        // No acceptable children, move to next node in tree
+        var current = self.current_node;
         while (current != self.root) {
-            const result = try self.nextSiblingOrSkip(current) orelse {
-                // No next sibling, go up to parent and continue
-                // or, if there is no parent, we're done
-                current = (parser.nodeParentNode(current)) orelse break;
-                continue;
-            };
-
-            if (!result.should_descend) {
-                // This is an .accept node - return it
-                self.current_node = result.node;
-                return try Node.toInterface(result.node);
+            if (try self.nextSibling(current)) |sibling| {
+                self.current_node = sibling;
+                return try Node.toInterface(sibling);
             }
 
-            // This is a .skip node - try to find acceptable children within it
-            if (try self.firstChild(result.node)) |child| {
-                self.current_node = child;
-                return try Node.toInterface(child);
-            }
-            // No acceptable children, continue looking at this node's siblings
-            current = result.node;
+            current = (try parser.nodeParentNode(current)) orelse break;
         }
 
         return null;
@@ -267,7 +234,7 @@ pub const TreeWalker = struct {
         if (self.current_node == self.root) return null;
 
         var current = self.current_node;
-        while (parser.nodePreviousSibling(current)) |previous| {
+        while (try parser.nodePreviousSibling(current)) |previous| {
             current = previous;
 
             switch (try NodeFilter.verify(self.what_to_show, self.filter_func, current)) {

src/browser/dom/walker.zig

@@ -44,39 +44,39 @@ pub const WalkerDepthFirst = struct {
         var n = cur orelse root;
 
         // TODO deinit next
-        if (parser.nodeFirstChild(n)) |next| {
+        if (try parser.nodeFirstChild(n)) |next| {
             return next;
         }
 
         // TODO deinit next
-        if (parser.nodeNextSibling(n)) |next| {
+        if (try parser.nodeNextSibling(n)) |next| {
             return next;
         }
 
         // TODO deinit parent
         // Back to the parent of cur.
         // If cur has no parent, then the iteration is over.
-        var parent = parser.nodeParentNode(n) orelse return null;
+        var parent = try parser.nodeParentNode(n) orelse return null;
 
         // TODO deinit lastchild
-        var lastchild = parser.nodeLastChild(parent);
+        var lastchild = try parser.nodeLastChild(parent);
         while (n != root and n == lastchild) {
             n = parent;
 
             // TODO deinit parent
             // Back to the prev's parent.
             // If prev has no parent, then the loop must stop.
-            parent = parser.nodeParentNode(n) orelse break;
+            parent = try parser.nodeParentNode(n) orelse break;
 
             // TODO deinit lastchild
-            lastchild = parser.nodeLastChild(parent);
+            lastchild = try parser.nodeLastChild(parent);
         }
 
         if (n == root) {
             return null;
         }
 
-        return parser.nodeNextSibling(n);
+        return try parser.nodeNextSibling(n);
     }
 };
 
@@ -84,14 +84,14 @@ pub const WalkerDepthFirst = struct {
 pub const WalkerChildren = struct {
     pub fn get_next(_: WalkerChildren, root: *parser.Node, cur: ?*parser.Node) !?*parser.Node {
         // On walk start, we return the first root's child.
-        if (cur == null) return parser.nodeFirstChild(root);
+        if (cur == null) return try parser.nodeFirstChild(root);
 
         // If cur is root, then return null.
         // This is a special case, if the root is included in the walk, we
         // don't want to go further to find children.
         if (root == cur.?) return null;
 
-        return parser.nodeNextSibling(cur.?);
+        return try parser.nodeNextSibling(cur.?);
     }
 };
 

src/browser/dump.zig

@@ -26,13 +26,7 @@ pub const Opts = struct {
     // set to include element shadowroots in the dump
     page: ?*const Page = null,
 
-    strip_mode: StripMode = .{},
-
-    pub const StripMode = struct {
-        js: bool = false,
-        ui: bool = false,
-        css: bool = false,
-    };
+    exclude_scripts: bool = false,
 };
 
 // writer must be a std.io.Writer
@@ -47,8 +41,8 @@ pub fn writeDocType(doc_type: *parser.DocumentType, writer: *std.Io.Writer) !voi
     try writer.writeAll("<!DOCTYPE ");
     try writer.writeAll(try parser.documentTypeGetName(doc_type));
 
-    const public_id = parser.documentTypeGetPublicId(doc_type);
-    const system_id = parser.documentTypeGetSystemId(doc_type);
+    const public_id = try parser.documentTypeGetPublicId(doc_type);
+    const system_id = try parser.documentTypeGetSystemId(doc_type);
     if (public_id.len != 0 and system_id.len != 0) {
         try writer.writeAll(" PUBLIC \"");
         try writeEscapedAttributeValue(writer, public_id);
@@ -69,11 +63,11 @@ pub fn writeDocType(doc_type: *parser.DocumentType, writer: *std.Io.Writer) !voi
 }
 
 pub fn writeNode(node: *parser.Node, opts: Opts, writer: *std.Io.Writer) anyerror!void {
-    switch (parser.nodeType(node)) {
+    switch (try parser.nodeType(node)) {
         .element => {
             // open the tag
             const tag_type = try parser.nodeHTMLGetTagType(node) orelse .undef;
-            if (try isStripped(tag_type, node, opts.strip_mode)) {
+            if (opts.exclude_scripts and try isScriptOrRelated(tag_type, node)) {
                 return;
             }
 
@@ -110,7 +104,7 @@ pub fn writeNode(node: *parser.Node, opts: Opts, writer: *std.Io.Writer) anyerro
             if (try isVoid(parser.nodeToElement(node))) return;
 
             if (tag_type == .script) {
-                try writer.writeAll(parser.nodeTextContent(node) orelse "");
+                try writer.writeAll(try parser.nodeTextContent(node) orelse "");
             } else {
                 // write the children
                 // TODO avoid recursion
@@ -123,17 +117,17 @@ pub fn writeNode(node: *parser.Node, opts: Opts, writer: *std.Io.Writer) anyerro
             try writer.writeAll(">");
         },
         .text => {
-            const v = parser.nodeValue(node) orelse return;
+            const v = try parser.nodeValue(node) orelse return;
             try writeEscapedTextNode(writer, v);
         },
         .cdata_section => {
-            const v = parser.nodeValue(node) orelse return;
+            const v = try parser.nodeValue(node) orelse return;
             try writer.writeAll("<![CDATA[");
             try writer.writeAll(v);
             try writer.writeAll("]]>");
         },
         .comment => {
-            const v = parser.nodeValue(node) orelse return;
+            const v = try parser.nodeValue(node) orelse return;
             try writer.writeAll("<!--");
             try writer.writeAll(v);
             try writer.writeAll("-->");
@@ -165,22 +159,9 @@ pub fn writeChildren(root: *parser.Node, opts: Opts, writer: *std.Io.Writer) !vo
     }
 }
 
-fn isStripped(tag_type: parser.Tag, node: *parser.Node, strip_mode: Opts.StripMode) !bool {
-    if (strip_mode.js and try isJsRelated(tag_type, node)) {
-        return true;
-    }
-
-    if (strip_mode.css and try isCssRelated(tag_type, node)) {
-        return true;
-    }
-
-    if (strip_mode.ui and try isUIRelated(tag_type, node)) {
-        return true;
-    }
-    return false;
-}
-
-fn isJsRelated(tag_type: parser.Tag, node: *parser.Node) !bool {
+// When `exclude_scripts` is passed to dump, we don't include <script> tags.
+// We also want to omit <link rel=preload as=ascript>
+fn isScriptOrRelated(tag_type: parser.Tag, node: *parser.Node) !bool {
     if (tag_type == .script) {
         return true;
     }
@@ -197,34 +178,6 @@ fn isJsRelated(tag_type: parser.Tag, node: *parser.Node) !bool {
     return false;
 }
 
-fn isCssRelated(tag_type: parser.Tag, node: *parser.Node) !bool {
-    if (tag_type == .style) {
-        return true;
-    }
-    if (tag_type == .link) {
-        const el = parser.nodeToElement(node);
-        const rel = try parser.elementGetAttribute(el, "rel") orelse return false;
-        return std.ascii.eqlIgnoreCase(rel, "stylesheet");
-    }
-    return false;
-}
-
-fn isUIRelated(tag_type: parser.Tag, node: *parser.Node) !bool {
-    if (try isCssRelated(tag_type, node)) {
-        return true;
-    }
-    if (tag_type == .img or tag_type == .picture or tag_type == .video) {
-        return true;
-    }
-    if (tag_type == .undef) {
-        const name = try parser.nodeLocalName(node);
-        if (std.mem.eql(u8, name, "svg")) {
-            return true;
-        }
-    }
-    return false;
-}
-
 // area, base, br, col, embed, hr, img, input, link, meta, source, track, wbr
 // https://html.spec.whatwg.org/#void-elements
 fn isVoid(elem: *parser.Element) !bool {
@@ -236,10 +189,10 @@ fn isVoid(elem: *parser.Element) !bool {
     };
 }
 
-fn writeEscapedTextNode(writer: *std.Io.Writer, value: []const u8) !void {
+fn writeEscapedTextNode(writer: anytype, value: []const u8) !void {
     var v = value;
     while (v.len > 0) {
-        const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>', 194 }) orelse {
+        const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>' }) orelse {
             return writer.writeAll(v);
         };
         try writer.writeAll(v[0..index]);
@@ -247,22 +200,13 @@ fn writeEscapedTextNode(writer: *std.Io.Writer, value: []const u8) !void {
             '&' => try writer.writeAll("&amp;"),
             '<' => try writer.writeAll("&lt;"),
             '>' => try writer.writeAll("&gt;"),
-            194 => {
-                // non breaking space
-                if (v.len > index + 1 and v[index + 1] == 160) {
-                    try writer.writeAll("&nbsp;");
-                    v = v[index + 2 ..];
-                    continue;
-                }
-                try writer.writeByte(194);
-            },
             else => unreachable,
         }
         v = v[index + 1 ..];
     }
 }
 
-fn writeEscapedAttributeValue(writer: *std.Io.Writer, value: []const u8) !void {
+fn writeEscapedAttributeValue(writer: anytype, value: []const u8) !void {
     var v = value;
     while (v.len > 0) {
         const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>', '"' }) orelse {
@@ -282,7 +226,7 @@ fn writeEscapedAttributeValue(writer: *std.Io.Writer, value: []const u8) !void {
 
 const testing = std.testing;
 test "dump.writeHTML" {
-    parser.init();
+    try parser.init();
     defer parser.deinit();
 
     try testWriteHTML(

src/browser/encoding/TextDecoder.zig

@@ -19,6 +19,7 @@
 const std = @import("std");
 const log = @import("../../log.zig");
 
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 // https://encoding.spec.whatwg.org/#interface-textdecoder
@@ -69,8 +70,8 @@ pub fn get_fatal(self: *const TextDecoder) bool {
 const DecodeOptions = struct {
     stream: bool = false,
 };
-pub fn _decode(self: *TextDecoder, str_: ?[]const u8, opts_: ?DecodeOptions, page: *Page) ![]const u8 {
-    var str = str_ orelse return "";
+pub fn _decode(self: *TextDecoder, input_: ?[]const u8, opts_: ?DecodeOptions, page: *Page) ![]const u8 {
+    var str = input_ orelse return "";
     const opts: DecodeOptions = opts_ orelse .{};
 
     if (self.stream.items.len > 0) {

src/browser/encoding/TextEncoder.zig

@@ -18,7 +18,7 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 
 // https://encoding.spec.whatwg.org/#interface-textencoder
 const TextEncoder = @This();
@@ -31,7 +31,7 @@ pub fn get_encoding(_: *const TextEncoder) []const u8 {
     return "utf-8";
 }
 
-pub fn _encode(_: *const TextEncoder, v: []const u8) !js.TypedArray(u8) {
+pub fn _encode(_: *const TextEncoder, v: []const u8) !Env.TypedArray(u8) {
     // Ensure the input is a valid utf-8
     // It seems chrome accepts invalid utf-8 sequence.
     //

src/browser/env.zig

@@ -0,0 +1,51 @@
+const std = @import("std");
+
+const Page = @import("page.zig").Page;
+const js = @import("../runtime/js.zig");
+const generate = @import("../runtime/generate.zig");
+
+const WebApis = struct {
+    // Wrapped like this for debug ergonomics.
+    // When we create our Env, a few lines down, we define it as:
+    //   pub const Env = js.Env(*Page, WebApis);
+    //
+    // If there's a compile time error witht he Env, it's type will be readable,
+    // i.e.: runtime.js.Env(*browser.env.Page, browser.env.WebApis)
+    //
+    // But if we didn't wrap it in the struct, like we once didn't, and defined
+    // env as:
+    //   pub const Env = js.Env(*Page, Interfaces);
+    //
+    // Because Interfaces is an anynoumous type, it doesn't have a friendly name
+    // and errors would be something like:
+    //   runtime.js.Env(*browser.Page, .{...A HUNDRED TYPES...})
+    pub const Interfaces = generate.Tuple(.{
+        @import("crypto/crypto.zig").Crypto,
+        @import("console/console.zig").Console,
+        @import("css/css.zig").Interfaces,
+        @import("cssom/cssom.zig").Interfaces,
+        @import("dom/dom.zig").Interfaces,
+        @import("dom/shadow_root.zig").ShadowRoot,
+        @import("encoding/encoding.zig").Interfaces,
+        @import("events/event.zig").Interfaces,
+        @import("html/html.zig").Interfaces,
+        @import("iterator/iterator.zig").Interfaces,
+        @import("storage/storage.zig").Interfaces,
+        @import("url/url.zig").Interfaces,
+        @import("xhr/xhr.zig").Interfaces,
+        @import("xhr/form_data.zig").Interfaces,
+        @import("xhr/File.zig"),
+        @import("xmlserializer/xmlserializer.zig").Interfaces,
+        @import("fetch/fetch.zig").Interfaces,
+        @import("streams/streams.zig").Interfaces,
+    });
+};
+
+pub const JsThis = Env.JsThis;
+pub const JsObject = Env.JsObject;
+pub const Function = Env.Function;
+pub const Promise = Env.Promise;
+pub const PromiseResolver = Env.PromiseResolver;
+
+pub const Env = js.Env(*Page, WebApis);
+pub const Global = @import("html/window.zig").Window;

src/browser/events/composition_event.zig

@@ -1,57 +0,0 @@
-// Copyright (C) 2023-2025  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-
-const parser = @import("../netsurf.zig");
-
-// https://developer.mozilla.org/en-US/docs/Web/API/CompositionEvent
-pub const CompositionEvent = struct {
-    data: []const u8,
-    proto: parser.Event,
-
-    pub const union_make_copy = true;
-    pub const prototype = *parser.Event;
-
-    pub const ConstructorOptions = struct {
-        data: []const u8 = "",
-    };
-
-    pub fn constructor(event_type: []const u8, options_: ?ConstructorOptions) !CompositionEvent {
-        const options: ConstructorOptions = options_ orelse .{};
-
-        const event = try parser.eventCreate();
-        defer parser.eventDestroy(event);
-        try parser.eventInit(event, event_type, .{});
-        parser.eventSetInternalType(event, .composition_event);
-
-        return .{
-            .proto = event.*,
-            .data = options.data,
-        };
-    }
-
-    pub fn get_data(self: *const CompositionEvent) []const u8 {
-        return self.data;
-    }
-};
-
-const testing = @import("../../testing.zig");
-test "Browser: Events.Composition" {
-    try testing.htmlRunner("events/composition.html");
-}

src/browser/events/custom_event.zig

@@ -16,10 +16,9 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
 const Event = @import("event.zig").Event;
-
+const JsObject = @import("../env.zig").JsObject;
 const netsurf = @import("../netsurf.zig");
 
 // https://dom.spec.whatwg.org/#interface-customevent
@@ -28,13 +27,13 @@ pub const CustomEvent = struct {
     pub const union_make_copy = true;
 
     proto: parser.Event,
-    detail: ?js.Object,
+    detail: ?JsObject,
 
     const CustomEventInit = struct {
         bubbles: bool = false,
         cancelable: bool = false,
         composed: bool = false,
-        detail: ?js.Object = null,
+        detail: ?JsObject = null,
     };
 
     pub fn constructor(event_type: []const u8, opts_: ?CustomEventInit) !CustomEvent {
@@ -54,7 +53,7 @@ pub const CustomEvent = struct {
         };
     }
 
-    pub fn get_detail(self: *CustomEvent) ?js.Object {
+    pub fn get_detail(self: *CustomEvent) ?JsObject {
         return self.detail;
     }
 
@@ -65,7 +64,7 @@ pub const CustomEvent = struct {
         event_type: []const u8,
         can_bubble: bool,
         cancelable: bool,
-        maybe_detail: ?js.Object,
+        maybe_detail: ?JsObject,
     ) !void {
         // This function can only be called after the constructor has called.
         // So we assume proto is initialized already by constructor.

src/browser/events/event.zig

@@ -17,12 +17,11 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const Allocator = std.mem.Allocator;
 
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
-const generate = @import("../js/generate.zig");
+const generate = @import("../../runtime/generate.zig");
 
 const Page = @import("../page.zig").Page;
 const Node = @import("../dom/node.zig").Node;
@@ -37,9 +36,6 @@ const MouseEvent = @import("mouse_event.zig").MouseEvent;
 const KeyboardEvent = @import("keyboard_event.zig").KeyboardEvent;
 const ErrorEvent = @import("../html/error_event.zig").ErrorEvent;
 const MessageEvent = @import("../dom/MessageChannel.zig").MessageEvent;
-const PopStateEvent = @import("../html/History.zig").PopStateEvent;
-const CompositionEvent = @import("composition_event.zig").CompositionEvent;
-const NavigationCurrentEntryChangeEvent = @import("../navigation/navigation.zig").NavigationCurrentEntryChangeEvent;
 
 // Event interfaces
 pub const Interfaces = .{
@@ -50,9 +46,6 @@ pub const Interfaces = .{
     KeyboardEvent,
     ErrorEvent,
     MessageEvent,
-    PopStateEvent,
-    CompositionEvent,
-    NavigationCurrentEntryChangeEvent,
 };
 
 pub const Union = generate.Union(Interfaces);
@@ -77,14 +70,9 @@ pub const Event = struct {
             .custom_event => .{ .CustomEvent = @as(*CustomEvent, @ptrCast(evt)).* },
             .progress_event => .{ .ProgressEvent = @as(*ProgressEvent, @ptrCast(evt)).* },
             .mouse_event => .{ .MouseEvent = @as(*parser.MouseEvent, @ptrCast(evt)) },
-            .error_event => .{ .ErrorEvent = (@as(*ErrorEvent, @fieldParentPtr("proto", evt))).* },
+            .error_event => .{ .ErrorEvent = @as(*ErrorEvent, @ptrCast(evt)).* },
             .message_event => .{ .MessageEvent = @as(*MessageEvent, @ptrCast(evt)).* },
             .keyboard_event => .{ .KeyboardEvent = @as(*parser.KeyboardEvent, @ptrCast(evt)) },
-            .pop_state => .{ .PopStateEvent = @as(*PopStateEvent, @ptrCast(evt)).* },
-            .composition_event => .{ .CompositionEvent = (@as(*CompositionEvent, @fieldParentPtr("proto", evt))).* },
-            .navigation_current_entry_change_event => .{
-                .NavigationCurrentEntryChangeEvent = @as(*NavigationCurrentEntryChangeEvent, @ptrCast(evt)).*,
-            },
         };
     }
 
@@ -96,8 +84,8 @@ pub const Event = struct {
 
     // Getters
 
-    pub fn get_type(self: *parser.Event) []const u8 {
-        return parser.eventType(self);
+    pub fn get_type(self: *parser.Event) ![]const u8 {
+        return try parser.eventType(self);
     }
 
     pub fn get_target(self: *parser.Event, page: *Page) !?EventTargetUnion {
@@ -170,7 +158,7 @@ pub const Event = struct {
         const et_ = parser.eventTarget(self);
         const et = et_ orelse return &.{};
 
-        var node: ?*parser.Node = switch (parser.eventTargetInternalType(et)) {
+        var node: ?*parser.Node = switch (try parser.eventTargetInternalType(et)) {
             .libdom_node => @as(*parser.Node, @ptrCast(et)),
             .plain => parser.eventTargetToNode(et),
             else => {
@@ -186,8 +174,8 @@ pub const Event = struct {
                 .node = try Node.toInterface(n),
             });
 
-            node = parser.nodeParentNode(n);
-            if (node == null and parser.nodeType(n) == .document_fragment) {
+            node = try parser.nodeParentNode(n);
+            if (node == null and try parser.nodeType(n) == .document_fragment) {
                 // we have a non-continuous hook from a shadowroot to its host (
                 // it's parent element). libdom doesn't really support ShdowRoots
                 // and, for the most part, that works out well since it naturally
@@ -228,15 +216,18 @@ pub const Event = struct {
 pub const EventHandler = struct {
     once: bool,
     capture: bool,
-    callback: js.Function,
+    callback: Function,
     node: parser.EventNode,
     listener: *parser.EventListener,
 
-    pub const Listener = union(enum) {
-        function: js.Function,
-        object: js.Object,
+    const Env = @import("../env.zig").Env;
+    const Function = Env.Function;
 
-        pub fn callback(self: Listener, target: *parser.EventTarget) !?js.Function {
+    pub const Listener = union(enum) {
+        function: Function,
+        object: Env.JsObject,
+
+        pub fn callback(self: Listener, target: *parser.EventTarget) !?Function {
             return switch (self) {
                 .function => |func| try func.withThis(target),
                 .object => |obj| blk: {
@@ -337,7 +328,7 @@ pub const EventHandler = struct {
     fn handle(node: *parser.EventNode, event: *parser.Event) void {
         const ievent = Event.toInterface(event);
         const self: *EventHandler = @fieldParentPtr("node", node);
-        var result: js.Function.Result = undefined;
+        var result: Function.Result = undefined;
         self.callback.tryCall(void, .{ievent}, &result) catch {
             log.debug(.user_script, "callback error", .{
                 .err = result.exception,
@@ -348,7 +339,7 @@ pub const EventHandler = struct {
 
         if (self.once) {
             const target = parser.eventTarget(event).?;
-            const typ = parser.eventType(event);
+            const typ = parser.eventType(event) catch return;
             parser.eventTargetRemoveEventListener(
                 target,
                 typ,
@@ -403,40 +394,6 @@ const SignalCallback = struct {
     }
 };
 
-pub fn DirectEventHandler(
-    comptime TargetT: type,
-    target: *TargetT,
-    event_type: []const u8,
-    maybe_listener: ?EventHandler.Listener,
-    cb: *?js.Function,
-    page_arena: std.mem.Allocator,
-) !void {
-    const event_target = parser.toEventTarget(TargetT, target);
-
-    // Check if we have a listener set.
-    if (cb.*) |callback| {
-        const listener = try parser.eventTargetHasListener(event_target, event_type, false, callback.id);
-        std.debug.assert(listener != null);
-        try parser.eventTargetRemoveEventListener(event_target, event_type, listener.?, false);
-    }
-
-    if (maybe_listener) |listener| {
-        switch (listener) {
-            // If an object is given as listener, do nothing.
-            .object => {},
-            .function => |callback| {
-                _ = try EventHandler.register(page_arena, event_target, event_type, listener, null) orelse unreachable;
-                cb.* = callback;
-
-                return;
-            },
-        }
-    }
-
-    // Just unset the listener.
-    cb.* = null;
-}
-
 const testing = @import("../../testing.zig");
 test "Browser: Event" {
     try testing.htmlRunner("events/event.html");

src/browser/events/keyboard_event.zig

@@ -22,6 +22,7 @@ const builtin = @import("builtin");
 
 const parser = @import("../netsurf.zig");
 const Event = @import("event.zig").Event;
+const JsObject = @import("../env.zig").JsObject;
 
 // TODO: We currently don't have a UIEvent interface so we skip it in the prototype chain.
 // https://developer.mozilla.org/en-US/docs/Web/API/UIEvent
@@ -53,8 +54,8 @@ pub const KeyboardEvent = struct {
     pub fn constructor(event_type: []const u8, maybe_options: ?ConstructorOptions) !*parser.KeyboardEvent {
         const options: ConstructorOptions = maybe_options orelse .{};
 
-        const event = try parser.keyboardEventCreate();
-        parser.eventSetInternalType(@ptrCast(event), .keyboard_event);
+        var event = try parser.keyboardEventCreate();
+        parser.eventSetInternalType(@ptrCast(&event), .keyboard_event);
 
         try parser.keyboardEventInit(
             event,

src/browser/events/mouse_event.zig

@@ -21,6 +21,7 @@ const log = @import("../../log.zig");
 
 const parser = @import("../netsurf.zig");
 const Event = @import("event.zig").Event;
+const JsObject = @import("../env.zig").JsObject;
 
 // TODO: We currently don't have a UIEvent interface so we skip it in the prototype chain.
 // https://developer.mozilla.org/en-US/docs/Web/API/UIEvent
@@ -54,8 +55,8 @@ pub const MouseEvent = struct {
     pub fn constructor(event_type: []const u8, opts_: ?MouseEventInit) !*parser.MouseEvent {
         const opts = opts_ orelse MouseEventInit{};
 
-        const mouse_event = try parser.mouseEventCreate();
-        parser.eventSetInternalType(@ptrCast(mouse_event), .mouse_event);
+        var mouse_event = try parser.mouseEventCreate();
+        parser.eventSetInternalType(@ptrCast(&mouse_event), .mouse_event);
 
         try parser.mouseEventInit(mouse_event, event_type, .{
             .x = opts.clientX,
@@ -68,7 +69,7 @@ pub const MouseEvent = struct {
         });
 
         if (!std.mem.eql(u8, event_type, "click")) {
-            log.warn(.browser, "unsupported mouse event", .{ .event = event_type });
+            log.warn(.mouse_event, "unsupported mouse event", .{ .event = event_type });
         }
 
         return mouse_event;

src/browser/fetch/Headers.zig

@@ -17,13 +17,15 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const URL = @import("../../url.zig").URL;
 const Page = @import("../page.zig").Page;
 
 const iterator = @import("../iterator/iterator.zig");
 
+const v8 = @import("v8");
+const Env = @import("../env.zig").Env;
+
 // https://developer.mozilla.org/en-US/docs/Web/API/Headers
 const Headers = @This();
 
@@ -67,7 +69,7 @@ pub const HeadersInit = union(enum) {
     // Headers
     headers: *Headers,
     // Mappings
-    object: js.Object,
+    object: Env.JsObject,
 };
 
 pub fn constructor(_init: ?HeadersInit, page: *Page) !Headers {
@@ -157,7 +159,7 @@ pub fn _entries(self: *const Headers) HeadersEntryIterable {
     };
 }
 
-pub fn _forEach(self: *Headers, callback_fn: js.Function, this_arg: ?js.Object) !void {
+pub fn _forEach(self: *Headers, callback_fn: Env.Function, this_arg: ?Env.JsObject) !void {
     var iter = self.headers.iterator();
 
     const cb = if (this_arg) |this| try callback_fn.withThis(this) else callback_fn;

src/browser/fetch/Request.zig

@@ -17,7 +17,6 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 
 const URL = @import("../../url.zig").URL;
@@ -27,6 +26,9 @@ const Response = @import("./Response.zig");
 const Http = @import("../../http/Http.zig");
 const ReadableStream = @import("../streams/ReadableStream.zig");
 
+const v8 = @import("v8");
+const Env = @import("../env.zig").Env;
+
 const Headers = @import("Headers.zig");
 const HeadersInit = @import("Headers.zig").HeadersInit;
 
@@ -78,27 +80,6 @@ pub const RequestCredentials = enum {
     }
 };
 
-pub const RequestMode = enum {
-    cors,
-    @"no-cors",
-    @"same-origin",
-    navigate,
-
-    pub fn fromString(str: []const u8) ?RequestMode {
-        for (std.enums.values(RequestMode)) |cache| {
-            if (std.ascii.eqlIgnoreCase(str, @tagName(cache))) {
-                return cache;
-            }
-        } else {
-            return null;
-        }
-    }
-
-    pub fn toString(self: RequestMode) []const u8 {
-        return @tagName(self);
-    }
-};
-
 // https://developer.mozilla.org/en-US/docs/Web/API/RequestInit
 pub const RequestInit = struct {
     body: ?[]const u8 = null,
@@ -107,7 +88,6 @@ pub const RequestInit = struct {
     headers: ?HeadersInit = null,
     integrity: ?[]const u8 = null,
     method: ?[]const u8 = null,
-    mode: ?[]const u8 = null,
 };
 
 // https://developer.mozilla.org/en-US/docs/Web/API/Request/Request
@@ -117,8 +97,6 @@ method: Http.Method,
 url: [:0]const u8,
 cache: RequestCache,
 credentials: RequestCredentials,
-// no-cors is default is not built with constructor.
-mode: RequestMode = .@"no-cors",
 headers: Headers,
 body: ?[]const u8,
 body_used: bool = false,
@@ -137,11 +115,11 @@ pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Re
         },
     };
 
+    const body = if (options.body) |body| try arena.dupe(u8, body) else null;
     const cache = (if (options.cache) |cache| RequestCache.fromString(cache) else null) orelse RequestCache.default;
     const credentials = (if (options.credentials) |creds| RequestCredentials.fromString(creds) else null) orelse RequestCredentials.@"same-origin";
     const integrity = if (options.integrity) |integ| try arena.dupe(u8, integ) else "";
     const headers: Headers = if (options.headers) |hdrs| try Headers.constructor(hdrs, page) else .{};
-    const mode = (if (options.mode) |mode| RequestMode.fromString(mode) else null) orelse RequestMode.cors;
 
     const method: Http.Method = blk: {
         if (options.method) |given_method| {
@@ -157,19 +135,11 @@ pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Re
         }
     };
 
-    // Can't have a body on .GET or .HEAD.
-    const body: ?[]const u8 = blk: {
-        if (method == .GET or method == .HEAD) {
-            break :blk null;
-        } else break :blk if (options.body) |body| try arena.dupe(u8, body) else null;
-    };
-
     return .{
         .method = method,
         .url = url,
         .cache = cache,
         .credentials = credentials,
-        .mode = mode,
         .headers = headers,
         .body = body,
         .integrity = integrity,
@@ -179,7 +149,7 @@ pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Re
 pub fn get_body(self: *const Request, page: *Page) !?*ReadableStream {
     if (self.body) |body| {
         const stream = try ReadableStream.constructor(null, null, page);
-        try stream.queue.append(page.arena, .{ .string = body });
+        try stream.queue.append(page.arena, body);
         return stream;
     } else return null;
 }
@@ -211,10 +181,6 @@ pub fn get_method(self: *const Request) []const u8 {
     return @tagName(self.method);
 }
 
-pub fn get_mode(self: *const Request) RequestMode {
-    return self.mode;
-}
-
 pub fn get_url(self: *const Request) []const u8 {
     return self.url;
 }
@@ -239,42 +205,59 @@ pub fn _clone(self: *Request) !Request {
     };
 }
 
-pub fn _bytes(self: *Response, page: *Page) !js.Promise {
+pub fn _bytes(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
+
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    try resolver.resolve(self.body);
     self.body_used = true;
-    return page.js.resolvePromise(self.body);
+    return resolver.promise();
 }
 
-pub fn _json(self: *Response, page: *Page) !js.Promise {
+pub fn _json(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
+
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    const p = std.json.parseFromSliceLeaky(
+        std.json.Value,
+        page.call_arena,
+        self.body,
+        .{},
+    ) catch |e| {
+        log.info(.browser, "invalid json", .{ .err = e, .source = "Request" });
+        return error.SyntaxError;
+    };
+
+    try resolver.resolve(p);
     self.body_used = true;
-
-    if (self.body) |body| {
-        const p = std.json.parseFromSliceLeaky(
-            std.json.Value,
-            page.call_arena,
-            body,
-            .{},
-        ) catch |e| {
-            log.info(.browser, "invalid json", .{ .err = e, .source = "Request" });
-            return error.SyntaxError;
-        };
-
-        return page.js.resolvePromise(p);
-    }
-    return page.js.resolvePromise(null);
+    return resolver.promise();
 }
 
-pub fn _text(self: *Response, page: *Page) !js.Promise {
+pub fn _text(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
+
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    try resolver.resolve(self.body);
     self.body_used = true;
-    return page.js.resolvePromise(self.body);
+    return resolver.promise();
 }
 
 const testing = @import("../../testing.zig");

src/browser/fetch/Response.zig

@@ -17,9 +17,10 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 
+const v8 = @import("v8");
+
 const HttpClient = @import("../../http/Client.zig");
 const Http = @import("../../http/Http.zig");
 const URL = @import("../../url.zig").URL;
@@ -28,6 +29,7 @@ const ReadableStream = @import("../streams/ReadableStream.zig");
 const Headers = @import("Headers.zig");
 const HeadersInit = @import("Headers.zig").HeadersInit;
 
+const Env = @import("../env.zig").Env;
 const Mime = @import("../mime.zig").Mime;
 const Page = @import("../page.zig").Page;
 
@@ -39,10 +41,9 @@ status_text: []const u8 = "",
 headers: Headers,
 mime: ?Mime = null,
 url: []const u8 = "",
-body: ?[]const u8 = null,
+body: []const u8 = "",
 body_used: bool = false,
 redirected: bool = false,
-type: ResponseType = .basic,
 
 const ResponseBody = union(enum) {
     string: []const u8,
@@ -54,28 +55,6 @@ const ResponseOptions = struct {
     headers: ?HeadersInit = null,
 };
 
-pub const ResponseType = enum {
-    basic,
-    cors,
-    @"error",
-    @"opaque",
-    opaqueredirect,
-
-    pub fn fromString(str: []const u8) ?ResponseType {
-        for (std.enums.values(ResponseType)) |cache| {
-            if (std.ascii.eqlIgnoreCase(str, @tagName(cache))) {
-                return cache;
-            }
-        } else {
-            return null;
-        }
-    }
-
-    pub fn toString(self: ResponseType) []const u8 {
-        return @tagName(self);
-    }
-};
-
 pub fn constructor(_input: ?ResponseBody, _options: ?ResponseOptions, page: *Page) !Response {
     const arena = page.arena;
 
@@ -89,7 +68,7 @@ pub fn constructor(_input: ?ResponseBody, _options: ?ResponseOptions, page: *Pag
                 },
             }
         } else {
-            break :blk null;
+            break :blk "";
         }
     };
 
@@ -106,9 +85,7 @@ pub fn constructor(_input: ?ResponseBody, _options: ?ResponseOptions, page: *Pag
 
 pub fn get_body(self: *const Response, page: *Page) !*ReadableStream {
     const stream = try ReadableStream.constructor(null, null, page);
-    if (self.body) |body| {
-        try stream.queue.append(page.arena, .{ .string = body });
-    }
+    try stream.queue.append(page.arena, self.body);
     return stream;
 }
 
@@ -136,10 +113,6 @@ pub fn get_statusText(self: *const Response) []const u8 {
     return self.status_text;
 }
 
-pub fn get_type(self: *const Response) ResponseType {
-    return self.type;
-}
-
 pub fn get_url(self: *const Response) []const u8 {
     return self.url;
 }
@@ -159,48 +132,62 @@ pub fn _clone(self: *const Response) !Response {
         .redirected = self.redirected,
         .status = self.status,
         .url = self.url,
-        .type = self.type,
     };
 }
 
-pub fn _bytes(self: *Response, page: *Page) !js.Promise {
+pub fn _bytes(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
 
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    try resolver.resolve(self.body);
     self.body_used = true;
-    return page.js.resolvePromise(self.body);
+    return resolver.promise();
 }
 
-pub fn _json(self: *Response, page: *Page) !js.Promise {
+pub fn _json(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
 
-    if (self.body) |body| {
-        self.body_used = true;
-        const p = std.json.parseFromSliceLeaky(
-            std.json.Value,
-            page.call_arena,
-            body,
-            .{},
-        ) catch |e| {
-            log.info(.browser, "invalid json", .{ .err = e, .source = "Response" });
-            return error.SyntaxError;
-        };
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
 
-        return page.js.resolvePromise(p);
-    }
-    return page.js.resolvePromise(null);
+    const p = std.json.parseFromSliceLeaky(
+        std.json.Value,
+        page.call_arena,
+        self.body,
+        .{},
+    ) catch |e| {
+        log.info(.browser, "invalid json", .{ .err = e, .source = "Response" });
+        return error.SyntaxError;
+    };
+
+    try resolver.resolve(p);
+    self.body_used = true;
+    return resolver.promise();
 }
 
-pub fn _text(self: *Response, page: *Page) !js.Promise {
+pub fn _text(self: *Response, page: *Page) !Env.Promise {
     if (self.body_used) {
         return error.TypeError;
     }
-    self.body_used = true;
 
-    return page.js.resolvePromise(self.body);
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    try resolver.resolve(self.body);
+    self.body_used = true;
+    return resolver.promise();
 }
 
 const testing = @import("../../testing.zig");

src/browser/fetch/fetch.zig

@@ -19,7 +19,7 @@
 const std = @import("std");
 const log = @import("../../log.zig");
 
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 const Http = @import("../../http/Http.zig");
@@ -43,9 +43,9 @@ pub const Interfaces = .{
 };
 
 pub const FetchContext = struct {
-    page: *Page,
     arena: std.mem.Allocator,
-    promise_resolver: js.PersistentPromiseResolver,
+    js_ctx: *Env.JsContext,
+    promise_resolver: Env.PersistentPromiseResolver,
 
     method: Http.Method,
     url: []const u8,
@@ -53,7 +53,6 @@ pub const FetchContext = struct {
     headers: std.ArrayListUnmanaged([]const u8) = .empty,
     status: u16 = 0,
     mime: ?Mime = null,
-    mode: Request.RequestMode,
     transfer: ?*HttpClient.Transfer = null,
 
     /// This effectively takes ownership of the FetchContext.
@@ -63,22 +62,6 @@ pub const FetchContext = struct {
     pub fn toResponse(self: *const FetchContext) !Response {
         var headers: Headers = .{};
 
-        // seems to be the highest priority
-        const same_origin = try self.page.isSameOrigin(self.url);
-
-        // If the mode is "no-cors", we need to return this opaque/stripped Response.
-        // https://developer.mozilla.org/en-US/docs/Web/API/Response/type
-        if (!same_origin and self.mode == .@"no-cors") {
-            return Response{
-                .status = 0,
-                .headers = headers,
-                .mime = self.mime,
-                .body = null,
-                .url = self.url,
-                .type = .@"opaque",
-            };
-        }
-
         // convert into Headers
         for (self.headers.items) |hdr| {
             var iter = std.mem.splitScalar(u8, hdr, ':');
@@ -87,35 +70,22 @@ pub const FetchContext = struct {
             try headers.append(name, value, self.arena);
         }
 
-        const resp_type: Response.ResponseType = blk: {
-            if (same_origin or std.mem.startsWith(u8, self.url, "data:")) {
-                break :blk .basic;
-            }
-
-            break :blk switch (self.mode) {
-                .cors => .cors,
-                .@"same-origin", .navigate => .basic,
-                .@"no-cors" => unreachable,
-            };
-        };
-
         return Response{
             .status = self.status,
             .headers = headers,
             .mime = self.mime,
             .body = self.body.items,
             .url = self.url,
-            .type = resp_type,
         };
     }
 };
 
 // https://developer.mozilla.org/en-US/docs/Web/API/Window/fetch
-pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !js.Promise {
+pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !Env.Promise {
     const arena = page.arena;
 
     const req = try Request.constructor(input, options, page);
-    var headers = try page.http_client.newHeaders();
+    var headers = try Http.Headers.init();
 
     // Copy our headers into the HTTP headers.
     var header_iter = req.headers.headers.iterator();
@@ -131,16 +101,15 @@ pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !js.Promis
 
     try page.requestCookie(.{}).headersForRequest(arena, req.url, &headers);
 
-    const resolver = try page.js.createPromiseResolver(.page);
+    const resolver = page.main_context.createPersistentPromiseResolver();
 
     const fetch_ctx = try arena.create(FetchContext);
     fetch_ctx.* = .{
-        .page = page,
         .arena = arena,
+        .js_ctx = page.main_context,
         .promise_resolver = resolver,
         .method = req.method,
         .url = req.url,
-        .mode = req.mode,
     };
 
     try page.http_client.request(.{
@@ -201,6 +170,7 @@ pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !js.Promis
         .done_callback = struct {
             fn doneCallback(ctx: *anyopaque) !void {
                 const self: *FetchContext = @ptrCast(@alignCast(ctx));
+                defer self.promise_resolver.setWeak();
                 self.transfer = null;
 
                 log.info(.fetch, "request complete", .{
@@ -217,6 +187,7 @@ pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !js.Promis
         .error_callback = struct {
             fn errorCallback(ctx: *anyopaque, err: anyerror) void {
                 const self: *FetchContext = @ptrCast(@alignCast(ctx));
+                defer self.promise_resolver.setWeak();
                 self.transfer = null;
 
                 log.err(.fetch, "error", .{

src/browser/html/AbortController.zig

@@ -17,9 +17,9 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 const EventTarget = @import("../dom/event_target.zig").EventTarget;
 
@@ -113,12 +113,12 @@ pub const AbortSignal = struct {
     }
 
     const ThrowIfAborted = union(enum) {
-        exception: js.Exception,
+        exception: Env.Exception,
         undefined: void,
     };
     pub fn _throwIfAborted(self: *const AbortSignal, page: *Page) ThrowIfAborted {
         if (self.aborted) {
-            const ex = page.js.throw(self.reason orelse DEFAULT_REASON);
+            const ex = page.main_context.throw(self.reason orelse DEFAULT_REASON);
             return .{ .exception = ex };
         }
         return .{ .undefined = {} };

src/browser/html/DataSet.zig

@@ -17,8 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 const std = @import("std");
 const parser = @import("../netsurf.zig");
-const js = @import("../js/js.zig");
-
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 const Allocator = std.mem.Allocator;
@@ -27,7 +26,7 @@ const DataSet = @This();
 
 element: *parser.Element,
 
-pub fn named_get(self: *const DataSet, name: []const u8, _: *bool, page: *Page) !js.UndefinedOr([]const u8) {
+pub fn named_get(self: *const DataSet, name: []const u8, _: *bool, page: *Page) !Env.UndefinedOr([]const u8) {
     const normalized_name = try normalize(page.call_arena, name);
     if (try parser.elementGetAttribute(self.element, normalized_name)) |value| {
         return .{ .value = value };

src/browser/html/History.zig

@@ -1,183 +0,0 @@
-// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-const log = @import("../../log.zig");
-
-const js = @import("../js/js.zig");
-const Page = @import("../page.zig").Page;
-const Window = @import("window.zig").Window;
-
-// https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-history-interface
-const History = @This();
-
-const ScrollRestorationMode = enum {
-    pub const ENUM_JS_USE_TAG = true;
-
-    auto,
-    manual,
-};
-
-scroll_restoration: ScrollRestorationMode = .auto,
-
-pub fn get_length(_: *History, page: *Page) u32 {
-    return @intCast(page.session.navigation.entries.items.len);
-}
-
-pub fn get_scrollRestoration(self: *History) ScrollRestorationMode {
-    return self.scroll_restoration;
-}
-
-pub fn set_scrollRestoration(self: *History, mode: ScrollRestorationMode) void {
-    self.scroll_restoration = mode;
-}
-
-pub fn get_state(_: *History, page: *Page) !?js.Value {
-    if (page.session.navigation.currentEntry().state) |state| {
-        const value = try js.Value.fromJson(page.js, state);
-        return value;
-    } else {
-        return null;
-    }
-}
-
-pub fn _pushState(_: *const History, state: js.Object, _: ?[]const u8, _url: ?[]const u8, page: *Page) !void {
-    const arena = page.session.arena;
-    const url = if (_url) |u| try arena.dupe(u8, u) else try arena.dupe(u8, page.url.raw);
-
-    const json = state.toJson(arena) catch return error.DataClone;
-    _ = try page.session.navigation.pushEntry(url, json, page, true);
-}
-
-pub fn _replaceState(_: *const History, state: js.Object, _: ?[]const u8, _url: ?[]const u8, page: *Page) !void {
-    const arena = page.session.arena;
-
-    const entry = page.session.navigation.currentEntry();
-    const json = try state.toJson(arena);
-    const url = if (_url) |u| try arena.dupe(u8, u) else try arena.dupe(u8, page.url.raw);
-
-    entry.state = json;
-    entry.url = url;
-}
-
-pub fn go(_: *const History, delta: i32, page: *Page) !void {
-    // 0 behaves the same as no argument, both reloading the page.
-
-    const current = page.session.navigation.index;
-    const index_s: i64 = @intCast(@as(i64, @intCast(current)) + @as(i64, @intCast(delta)));
-    if (index_s < 0 or index_s > page.session.navigation.entries.items.len - 1) {
-        return;
-    }
-
-    const index = @as(usize, @intCast(index_s));
-    const entry = page.session.navigation.entries.items[index];
-
-    if (entry.url) |url| {
-        if (try page.isSameOrigin(url)) {
-            PopStateEvent.dispatch(entry.state, page);
-        }
-    }
-
-    _ = try page.session.navigation.navigate(entry.url, .{ .traverse = index }, page);
-}
-
-pub fn _go(self: *History, _delta: ?i32, page: *Page) !void {
-    try self.go(_delta orelse 0, page);
-}
-
-pub fn _back(self: *History, page: *Page) !void {
-    try self.go(-1, page);
-}
-
-pub fn _forward(self: *History, page: *Page) !void {
-    try self.go(1, page);
-}
-
-const parser = @import("../netsurf.zig");
-const Event = @import("../events/event.zig").Event;
-
-pub const PopStateEvent = struct {
-    pub const prototype = *Event;
-    pub const union_make_copy = true;
-
-    pub const EventInit = struct {
-        state: ?[]const u8 = null,
-    };
-
-    proto: parser.Event,
-    state: ?[]const u8,
-
-    pub fn constructor(event_type: []const u8, opts: ?EventInit) !PopStateEvent {
-        const event = try parser.eventCreate();
-        defer parser.eventDestroy(event);
-        try parser.eventInit(event, event_type, .{});
-        parser.eventSetInternalType(event, .pop_state);
-
-        const o = opts orelse EventInit{};
-
-        return .{
-            .proto = event.*,
-            .state = o.state,
-        };
-    }
-
-    // `hasUAVisualTransition` is not implemented. It isn't baseline so this is okay.
-
-    pub fn get_state(self: *const PopStateEvent, page: *Page) !?js.Value {
-        if (self.state) |state| {
-            const value = try js.Value.fromJson(page.js, state);
-            return value;
-        } else {
-            return null;
-        }
-    }
-
-    pub fn dispatch(state: ?[]const u8, page: *Page) void {
-        log.debug(.script_event, "dispatch popstate event", .{
-            .type = "popstate",
-            .source = "history",
-        });
-
-        var evt = PopStateEvent.constructor("popstate", .{ .state = state }) catch |err| {
-            log.err(.app, "event constructor error", .{
-                .err = err,
-                .type = "popstate",
-                .source = "history",
-            });
-
-            return;
-        };
-
-        _ = parser.eventTargetDispatchEvent(
-            parser.toEventTarget(Window, &page.window),
-            &evt.proto,
-        ) catch |err| {
-            log.err(.app, "dispatch popstate event error", .{
-                .err = err,
-                .type = "popstate",
-                .source = "history",
-            });
-        };
-    }
-};
-
-const testing = @import("../../testing.zig");
-test "Browser: HTML.History" {
-    try testing.htmlRunner("html/history/history.html");
-    try testing.htmlRunner("html/history/history2.html");
-}

src/browser/html/document.zig

@@ -115,69 +115,67 @@ pub const HTMLDocument = struct {
     }
 
     pub fn _getElementsByName(self: *parser.DocumentHTML, name: []const u8, page: *Page) !NodeList {
+        const arena = page.arena;
         var list: NodeList = .{};
 
-        if (name.len == 0) {
-            return list;
-        }
+        if (name.len == 0) return list;
 
         const root = parser.documentHTMLToNode(self);
-        var c = try collection.HTMLCollectionByName(root, name, .{
+        var c = try collection.HTMLCollectionByName(arena, root, name, .{
             .include_root = false,
         });
 
         const ln = try c.get_length();
-        try list.ensureTotalCapacity(page.arena, ln);
-
         var i: u32 = 0;
-        while (i < ln) : (i += 1) {
+        while (i < ln) {
             const n = try c.item(i) orelse break;
-            list.appendAssumeCapacity(n);
+            try list.append(arena, n);
+            i += 1;
         }
 
         return list;
     }
 
-    pub fn get_images(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(parser.documentHTMLToNode(self), "img", .{
+    pub fn get_images(self: *parser.DocumentHTML, page: *Page) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(page.arena, parser.documentHTMLToNode(self), "img", .{
             .include_root = false,
         });
     }
 
-    pub fn get_embeds(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(parser.documentHTMLToNode(self), "embed", .{
+    pub fn get_embeds(self: *parser.DocumentHTML, page: *Page) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(page.arena, parser.documentHTMLToNode(self), "embed", .{
             .include_root = false,
         });
     }
 
-    pub fn get_plugins(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return get_embeds(self);
+    pub fn get_plugins(self: *parser.DocumentHTML, page: *Page) !collection.HTMLCollection {
+        return get_embeds(self, page);
     }
 
-    pub fn get_forms(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(parser.documentHTMLToNode(self), "form", .{
+    pub fn get_forms(self: *parser.DocumentHTML, page: *Page) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(page.arena, parser.documentHTMLToNode(self), "form", .{
             .include_root = false,
         });
     }
 
-    pub fn get_scripts(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByTagName(parser.documentHTMLToNode(self), "script", .{
+    pub fn get_scripts(self: *parser.DocumentHTML, page: *Page) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByTagName(page.arena, parser.documentHTMLToNode(self), "script", .{
             .include_root = false,
         });
     }
 
-    pub fn get_applets(_: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionEmpty();
+    pub fn get_applets(_: *parser.DocumentHTML) !collection.HTMLCollection {
+        return try collection.HTMLCollectionEmpty();
     }
 
-    pub fn get_links(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByLinks(parser.documentHTMLToNode(self), .{
+    pub fn get_links(self: *parser.DocumentHTML) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByLinks(parser.documentHTMLToNode(self), .{
             .include_root = false,
         });
     }
 
-    pub fn get_anchors(self: *parser.DocumentHTML) collection.HTMLCollection {
-        return collection.HTMLCollectionByAnchors(parser.documentHTMLToNode(self), .{
+    pub fn get_anchors(self: *parser.DocumentHTML) !collection.HTMLCollection {
+        return try collection.HTMLCollectionByAnchors(parser.documentHTMLToNode(self), .{
             .include_root = false,
         });
     }
@@ -195,7 +193,7 @@ pub const HTMLDocument = struct {
     }
 
     pub fn set_location(_: *const parser.DocumentHTML, url: []const u8, page: *Page) !void {
-        return page.navigateFromWebAPI(url, .{ .reason = .script }, .{ .push = null });
+        return page.navigateFromWebAPI(url, .{ .reason = .script });
     }
 
     pub fn get_designMode(_: *parser.DocumentHTML) []const u8 {

src/browser/html/elements.zig

@@ -18,9 +18,9 @@
 const std = @import("std");
 const log = @import("../../log.zig");
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
-const generate = @import("../js/generate.zig");
+const generate = @import("../../runtime/generate.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 const urlStitch = @import("../../url.zig").URL.stitch;
@@ -133,14 +133,14 @@ pub const HTMLElement = struct {
 
     pub fn get_innerText(e: *parser.ElementHTML) ![]const u8 {
         const n = @as(*parser.Node, @ptrCast(e));
-        return parser.nodeTextContent(n) orelse "";
+        return try parser.nodeTextContent(n) orelse "";
     }
 
     pub fn set_innerText(e: *parser.ElementHTML, s: []const u8) !void {
         const n = @as(*parser.Node, @ptrCast(e));
 
         // create text node.
-        const doc = parser.nodeOwnerDocument(n) orelse return error.NoDocument;
+        const doc = try parser.nodeOwnerDocument(n) orelse return error.NoDocument;
         const t = try parser.documentCreateTextNode(doc, s);
 
         // remove existing children.
@@ -167,12 +167,12 @@ pub const HTMLElement = struct {
         focusVisible: bool,
     };
     pub fn _focus(e: *parser.ElementHTML, _: ?FocusOpts, page: *Page) !void {
-        if (!page.isNodeAttached(@ptrCast(e))) {
+        if (!try page.isNodeAttached(@ptrCast(e))) {
             return;
         }
 
         const Document = @import("../dom/document.zig").Document;
-        const root_node = parser.nodeGetRootNode(@ptrCast(e));
+        const root_node = try parser.nodeGetRootNode(@ptrCast(e));
         try Document.setFocus(@ptrCast(root_node), e, page);
     }
 };
@@ -251,7 +251,7 @@ pub const HTMLAnchorElement = struct {
     }
 
     pub fn get_text(self: *parser.Anchor) !?[]const u8 {
-        return parser.nodeTextContent(parser.anchorToNode(self));
+        return try parser.nodeTextContent(parser.anchorToNode(self));
     }
 
     pub fn set_text(self: *parser.Anchor, v: []const u8) !void {
@@ -281,7 +281,7 @@ pub const HTMLAnchorElement = struct {
     // TODO return a disposable string
     pub fn get_protocol(self: *parser.Anchor, page: *Page) ![]const u8 {
         var u = try url(self, page);
-        return u.get_protocol();
+        return u.get_protocol(page);
     }
 
     pub fn set_protocol(self: *parser.Anchor, v: []const u8, page: *Page) !void {
@@ -732,9 +732,6 @@ pub const HTMLInputElement = struct {
     pub fn set_value(self: *parser.Input, value: []const u8) !void {
         try parser.inputSetValue(self, value);
     }
-    pub fn _select(_: *parser.Input) void {
-        log.debug(.web_api, "not implemented", .{ .feature = "HTMLInputElement select" });
-    }
 };
 
 pub const HTMLLIElement = struct {
@@ -760,21 +757,13 @@ pub const HTMLLinkElement = struct {
     pub const prototype = *HTMLElement;
     pub const subtype = .node;
 
-    pub fn get_rel(self: *parser.Link) ![]const u8 {
-        return parser.linkGetRel(self);
-    }
-
-    pub fn set_rel(self: *parser.Link, rel: []const u8) !void {
-        return parser.linkSetRel(self, rel);
-    }
-
     pub fn get_href(self: *parser.Link) ![]const u8 {
-        return parser.linkGetHref(self);
+        return try parser.linkGetHref(self);
     }
 
     pub fn set_href(self: *parser.Link, href: []const u8, page: *const Page) !void {
         const full = try urlStitch(page.call_arena, href, page.url.raw, .{});
-        return parser.linkSetHref(self, full);
+        return try parser.linkSetHref(self, full);
     }
 };
 
@@ -890,7 +879,7 @@ pub const HTMLScriptElement = struct {
             //    s.src = '...';
             // This should load the script.
             // addFromElement protects against double execution.
-            try page.script_manager.addFromElement(@ptrCast(@alignCast(self)), "dynamic");
+            try page.script_manager.addFromElement(@ptrCast(@alignCast(self)));
         }
     }
 
@@ -1003,22 +992,22 @@ pub const HTMLScriptElement = struct {
         );
     }
 
-    pub fn get_onload(self: *parser.Script, page: *Page) !?js.Function {
+    pub fn get_onload(self: *parser.Script, page: *Page) !?Env.Function {
         const state = page.getNodeState(@ptrCast(@alignCast(self))) orelse return null;
         return state.onload;
     }
 
-    pub fn set_onload(self: *parser.Script, function: ?js.Function, page: *Page) !void {
+    pub fn set_onload(self: *parser.Script, function: ?Env.Function, page: *Page) !void {
         const state = try page.getOrCreateNodeState(@ptrCast(@alignCast(self)));
         state.onload = function;
     }
 
-    pub fn get_onerror(self: *parser.Script, page: *Page) !?js.Function {
+    pub fn get_onerror(self: *parser.Script, page: *Page) !?Env.Function {
         const state = page.getNodeState(@ptrCast(@alignCast(self))) orelse return null;
         return state.onerror;
     }
 
-    pub fn set_onerror(self: *parser.Script, function: ?js.Function, page: *Page) !void {
+    pub fn set_onerror(self: *parser.Script, function: ?Env.Function, page: *Page) !void {
         const state = try page.getOrCreateNodeState(@ptrCast(@alignCast(self)));
         state.onerror = function;
     }
@@ -1053,84 +1042,68 @@ pub const HTMLSlotElement = struct {
         flatten: bool = false,
     };
     pub fn _assignedNodes(self: *parser.Slot, opts_: ?AssignedNodesOpts, page: *Page) ![]NodeUnion {
-        return findAssignedSlotNodes(self, opts_, false, page);
-    }
-
-    // This should return Union, instead of NodeUnion, but we want to re-use
-    // findAssignedSlotNodes. Returning NodeUnion is fine, as long as every element
-    // within is an Element. This could be more efficient
-    pub fn _assignedElements(self: *parser.Slot, opts_: ?AssignedNodesOpts, page: *Page) ![]NodeUnion {
-        return findAssignedSlotNodes(self, opts_, true, page);
-    }
-
-    fn findAssignedSlotNodes(self: *parser.Slot, opts_: ?AssignedNodesOpts, element_only: bool, page: *Page) ![]NodeUnion {
         const opts = opts_ orelse AssignedNodesOpts{ .flatten = false };
 
-        if (opts.flatten) {
-            log.debug(.web_api, "not implemented", .{ .feature = "HTMLSlotElement flatten assignedNodes" });
+        if (try findAssignedSlotNodes(self, opts, page)) |nodes| {
+            return nodes;
+        }
+
+        if (!opts.flatten) {
+            return &.{};
         }
 
         const node: *parser.Node = @ptrCast(@alignCast(self));
+        const nl = try parser.nodeGetChildNodes(node);
+        const len = try parser.nodeListLength(nl);
+        if (len == 0) {
+            return &.{};
+        }
 
-        // First we look for any explicitly assigned nodes (via the slot attribute)
-        {
-            const slot_name = try parser.elementGetAttribute(@ptrCast(@alignCast(self)), "name");
-            var root = parser.nodeGetRootNode(node);
-            if (page.getNodeState(root)) |state| {
-                if (state.shadow_root) |sr| {
-                    root = @ptrCast(@alignCast(sr.host));
-                }
+        var assigned = try page.call_arena.alloc(NodeUnion, len);
+        var i: usize = 0;
+        while (true) : (i += 1) {
+            const child = try parser.nodeListItem(nl, @intCast(i)) orelse break;
+            assigned[i] = try Node.toInterface(child);
+        }
+        return assigned[0..i];
+    }
+
+    fn findAssignedSlotNodes(self: *parser.Slot, opts: AssignedNodesOpts, page: *Page) !?[]NodeUnion {
+        if (opts.flatten) {
+            log.warn(.web_api, "not implemented", .{ .feature = "HTMLSlotElement flatten assignedNodes" });
+        }
+
+        const slot_name = try parser.elementGetAttribute(@ptrCast(@alignCast(self)), "name");
+        const node: *parser.Node = @ptrCast(@alignCast(self));
+        var root = try parser.nodeGetRootNode(node);
+        if (page.getNodeState(root)) |state| {
+            if (state.shadow_root) |sr| {
+                root = @ptrCast(@alignCast(sr.host));
             }
+        }
 
-            var arr: std.ArrayList(NodeUnion) = .empty;
-            const w = @import("../dom/walker.zig").WalkerChildren{};
-            var next: ?*parser.Node = null;
-            while (true) {
-                next = try w.get_next(root, next) orelse break;
-                if (parser.nodeType(next.?) != .element) {
-                    if (slot_name == null and !element_only) {
-                        // default slot (with no name), takes everything
-                        try arr.append(page.call_arena, try Node.toInterface(next.?));
-                    }
-                    continue;
-                }
-                const el: *parser.Element = @ptrCast(@alignCast(next.?));
-                const element_slot = try parser.elementGetAttribute(el, "slot");
-
-                if (nullableStringsAreEqual(slot_name, element_slot)) {
-                    // either they're the same string or they are both null
+        var arr: std.ArrayList(NodeUnion) = .empty;
+        const w = @import("../dom/walker.zig").WalkerChildren{};
+        var next: ?*parser.Node = null;
+        while (true) {
+            next = try w.get_next(root, next) orelse break;
+            if (try parser.nodeType(next.?) != .element) {
+                if (slot_name == null) {
+                    // default slot (with no name), takes everything
                     try arr.append(page.call_arena, try Node.toInterface(next.?));
-                    continue;
                 }
+                continue;
             }
-            if (arr.items.len > 0) {
-                return arr.items;
-            }
+            const el: *parser.Element = @ptrCast(@alignCast(next.?));
+            const element_slot = try parser.elementGetAttribute(el, "slot");
 
-            if (!opts.flatten) {
-                return &.{};
+            if (nullableStringsAreEqual(slot_name, element_slot)) {
+                // either they're the same string or they are both null
+                try arr.append(page.call_arena, try Node.toInterface(next.?));
+                continue;
             }
         }
-
-        // Since, we have no explicitly assigned nodes and flatten == false,
-        // we'll collect the children of the slot - the defaults.
-        {
-            const nl = try parser.nodeGetChildNodes(node);
-            const len = parser.nodeListLength(nl);
-            if (len == 0) {
-                return &.{};
-            }
-
-            var assigned = try page.call_arena.alloc(NodeUnion, len);
-            var i: usize = 0;
-            while (true) : (i += 1) {
-                const child = parser.nodeListItem(nl, @intCast(i)) orelse break;
-                if (!element_only or parser.nodeType(child) == .element) {
-                    assigned[i] = try Node.toInterface(child);
-                }
-            }
-            return assigned[0..i];
-        }
+        return if (arr.items.len == 0) null else arr.items;
     }
 
     fn nullableStringsAreEqual(a: ?[]const u8, b: ?[]const u8) bool {
@@ -1354,11 +1327,41 @@ test "Browser: HTML.HtmlStyleElement" {
 test "Browser: HTML.HtmlScriptElement" {
     try testing.htmlRunner("html/script/script.html");
     try testing.htmlRunner("html/script/inline_defer.html");
-    try testing.htmlRunner("html/script/import.html");
-    try testing.htmlRunner("html/script/dynamic_import.html");
-    try testing.htmlRunner("html/script/importmap.html");
 }
 
-test "Browser: HTML.HtmlSlotElement" {
-    try testing.htmlRunner("html/slot.html");
+test "Browser: HTML.HTMLSlotElement" {
+    try testing.htmlRunner("html/html_slot_element.html");
+}
+
+const Check = struct {
+    input: []const u8,
+    expected: ?[]const u8 = null, // Needed when input != expected
+};
+const bool_valids = [_]Check{
+    .{ .input = "true" },
+    .{ .input = "''", .expected = "false" },
+    .{ .input = "13.5", .expected = "true" },
+};
+const str_valids = [_]Check{
+    .{ .input = "'foo'", .expected = "foo" },
+    .{ .input = "5", .expected = "5" },
+    .{ .input = "''", .expected = "" },
+    .{ .input = "document", .expected = "[object HTMLDocument]" },
+};
+
+// .{ "elem.type = '5'", "5" },
+// .{ "elem.type", "text" },
+fn testProperty(
+    arena: std.mem.Allocator,
+    runner: *testing.JsRunner,
+    elem_dot_prop: []const u8,
+    always: ?[]const u8, // Ignores checks' expected if set
+    checks: []const Check,
+) !void {
+    for (checks) |check| {
+        try runner.testCases(&.{
+            .{ try std.mem.concat(arena, u8, &.{ elem_dot_prop, " = ", check.input }), null },
+            .{ elem_dot_prop, always orelse check.expected orelse check.input },
+        }, .{});
+    }
 }

src/browser/html/error_event.zig

@@ -15,7 +15,7 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-const js = @import("../js/js.zig");
+const Env = @import("../env.zig").Env;
 const parser = @import("../netsurf.zig");
 
 // https://developer.mozilla.org/en-US/docs/Web/API/ErrorEvent
@@ -28,21 +28,21 @@ pub const ErrorEvent = struct {
     filename: []const u8,
     lineno: i32,
     colno: i32,
-    @"error": ?js.Object,
+    @"error": ?Env.JsObject,
 
     const ErrorEventInit = struct {
         message: []const u8 = "",
         filename: []const u8 = "",
         lineno: i32 = 0,
         colno: i32 = 0,
-        @"error": ?js.Object = null,
+        @"error": ?Env.JsObject = null,
     };
 
     pub fn constructor(event_type: []const u8, opts: ?ErrorEventInit) !ErrorEvent {
         const event = try parser.eventCreate();
         defer parser.eventDestroy(event);
         try parser.eventInit(event, event_type, .{});
-        parser.eventSetInternalType(event, .error_event);
+        parser.eventSetInternalType(event, .event);
 
         const o = opts orelse ErrorEventInit{};
 
@@ -72,7 +72,7 @@ pub const ErrorEvent = struct {
         return self.colno;
     }
 
-    pub fn get_error(self: *const ErrorEvent) js.UndefinedOr(js.Object) {
+    pub fn get_error(self: *const ErrorEvent) Env.UndefinedOr(Env.JsObject) {
         if (self.@"error") |e| {
             return .{ .value = e };
         }

src/browser/html/form.zig

@@ -21,6 +21,7 @@ const Allocator = std.mem.Allocator;
 const parser = @import("../netsurf.zig");
 const Page = @import("../page.zig").Page;
 const HTMLElement = @import("elements.zig").HTMLElement;
+const FormData = @import("../xhr/form_data.zig").FormData;
 
 pub const HTMLFormElement = struct {
     pub const Self = parser.Form;

src/browser/html/history.zig

@@ -0,0 +1,93 @@
+// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+
+// https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-history-interface
+pub const History = struct {
+    const ScrollRestorationMode = enum {
+        auto,
+        manual,
+    };
+
+    scrollRestoration: ScrollRestorationMode = .auto,
+    state: std.json.Value = .null,
+
+    // count tracks the history length until we implement correctly pushstate.
+    count: u32 = 0,
+
+    pub fn get_length(self: *History) u32 {
+        // TODO return the real history length value.
+        return self.count;
+    }
+
+    pub fn get_scrollRestoration(self: *History) []const u8 {
+        return switch (self.scrollRestoration) {
+            .auto => "auto",
+            .manual => "manual",
+        };
+    }
+
+    pub fn set_scrollRestoration(self: *History, mode: []const u8) void {
+        if (std.mem.eql(u8, "manual", mode)) self.scrollRestoration = .manual;
+        if (std.mem.eql(u8, "auto", mode)) self.scrollRestoration = .auto;
+    }
+
+    pub fn get_state(self: *History) std.json.Value {
+        return self.state;
+    }
+
+    // TODO implement the function
+    // data must handle any argument. We could expect a std.json.Value but
+    // https://github.com/lightpanda-io/zig-js-runtime/issues/267 is missing.
+    pub fn _pushState(self: *History, data: []const u8, _: ?[]const u8, url: ?[]const u8) void {
+        self.count += 1;
+        _ = url;
+        _ = data;
+    }
+
+    // TODO implement the function
+    // data must handle any argument. We could expect a std.json.Value but
+    // https://github.com/lightpanda-io/zig-js-runtime/issues/267 is missing.
+    pub fn _replaceState(self: *History, data: []const u8, _: ?[]const u8, url: ?[]const u8) void {
+        _ = self;
+        _ = url;
+        _ = data;
+    }
+
+    // TODO implement the function
+    pub fn _go(self: *History, delta: ?i32) void {
+        _ = self;
+        _ = delta;
+    }
+
+    // TODO implement the function
+    pub fn _back(self: *History) void {
+        _ = self;
+    }
+
+    // TODO implement the function
+    pub fn _forward(self: *History) void {
+        _ = self;
+    }
+};
+
+const testing = @import("../../testing.zig");
+test "Browser: HTML.History" {
+    try testing.htmlRunner("html/history.html");
+}

src/browser/html/html.zig

@@ -21,7 +21,7 @@ const HTMLElem = @import("elements.zig");
 const SVGElem = @import("svg_elements.zig");
 const Window = @import("window.zig").Window;
 const Navigator = @import("navigator.zig").Navigator;
-const History = @import("History.zig");
+const History = @import("history.zig").History;
 const Location = @import("location.zig").Location;
 const MediaQueryList = @import("media_query_list.zig").MediaQueryList;
 

src/browser/html/iframe.zig

@@ -16,8 +16,10 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 const std = @import("std");
+const Allocator = std.mem.Allocator;
 
 const parser = @import("../netsurf.zig");
+const Page = @import("../page.zig").Page;
 const HTMLElement = @import("elements.zig").HTMLElement;
 
 // https://html.spec.whatwg.org/multipage/iframe-embed-object.html#htmliframeelement

src/browser/html/location.zig

@@ -16,73 +16,69 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const Uri = @import("std").Uri;
-
 const Page = @import("../page.zig").Page;
+
 const URL = @import("../url/url.zig").URL;
 
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-location-interface
 pub const Location = struct {
-    url: URL,
-
-    /// Browsers give such initial values when user not navigated yet:
-    /// Chrome  -> chrome://new-tab-page/
-    /// Firefox -> about:newtab
-    /// Safari  -> favorites://
-    pub const default = Location{
-        .url = .initWithoutSearchParams(Uri.parse("about:blank") catch unreachable),
-    };
+    url: ?URL = null,
 
     pub fn get_href(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_href(page);
+        if (self.url) |*u| return u.get_href(page);
+        return "";
     }
 
-    pub fn set_href(_: *const Location, href: []const u8, page: *Page) !void {
-        return page.navigateFromWebAPI(href, .{ .reason = .script }, .{ .push = null });
-    }
-
-    pub fn get_protocol(self: *Location) []const u8 {
-        return self.url.get_protocol();
+    pub fn get_protocol(self: *Location, page: *Page) ![]const u8 {
+        if (self.url) |*u| return u.get_protocol(page);
+        return "";
     }
 
     pub fn get_host(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_host(page);
+        if (self.url) |*u| return u.get_host(page);
+        return "";
     }
 
     pub fn get_hostname(self: *Location) []const u8 {
-        return self.url.get_hostname();
+        if (self.url) |*u| return u.get_hostname();
+        return "";
     }
 
     pub fn get_port(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_port(page);
+        if (self.url) |*u| return u.get_port(page);
+        return "";
     }
 
     pub fn get_pathname(self: *Location) []const u8 {
-        return self.url.get_pathname();
+        if (self.url) |*u| return u.get_pathname();
+        return "";
     }
 
     pub fn get_search(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_search(page);
+        if (self.url) |*u| return u.get_search(page);
+        return "";
     }
 
     pub fn get_hash(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_hash(page);
+        if (self.url) |*u| return u.get_hash(page);
+        return "";
     }
 
     pub fn get_origin(self: *Location, page: *Page) ![]const u8 {
-        return self.url.get_origin(page);
+        if (self.url) |*u| return u.get_origin(page);
+        return "";
     }
 
     pub fn _assign(_: *const Location, url: []const u8, page: *Page) !void {
-        return page.navigateFromWebAPI(url, .{ .reason = .script }, .{ .push = null });
+        return page.navigateFromWebAPI(url, .{ .reason = .script });
     }
 
     pub fn _replace(_: *const Location, url: []const u8, page: *Page) !void {
-        return page.navigateFromWebAPI(url, .{ .reason = .script }, .replace);
+        return page.navigateFromWebAPI(url, .{ .reason = .script });
     }
 
     pub fn _reload(_: *const Location, page: *Page) !void {
-        return page.navigateFromWebAPI(page.url.raw, .{ .reason = .script }, .reload);
+        return page.navigateFromWebAPI(page.url.raw, .{ .reason = .script });
     }
 
     pub fn _toString(self: *Location, page: *Page) ![]const u8 {

src/browser/html/media_query_list.zig

@@ -16,8 +16,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const js = @import("../js/js.zig");
 const parser = @import("../netsurf.zig");
+const Function = @import("../env.zig").Function;
 const EventTarget = @import("../dom/event_target.zig").EventTarget;
 
 // https://drafts.csswg.org/cssom-view/#the-mediaquerylist-interface
@@ -39,7 +39,7 @@ pub const MediaQueryList = struct {
         return self.media;
     }
 
-    pub fn _addListener(_: *const MediaQueryList, _: js.Function) void {}
+    pub fn _addListener(_: *const MediaQueryList, _: Function) void {}
 
-    pub fn _removeListener(_: *const MediaQueryList, _: js.Function) void {}
+    pub fn _removeListener(_: *const MediaQueryList, _: Function) void {}
 };

src/browser/html/svg_elements.zig

@@ -25,7 +25,7 @@ pub const SVGElement = struct {
     // Currently the prototype chain is not implemented (will not be returned by toInterface())
     // For that we need parser.SvgElement and the derived types with tags in the v-table.
     pub const prototype = *Element;
-    // While this is a Node, could consider not exposing the subtype until we have
+    // While this is a Node, could consider not exposing the subtype untill we have
     // a Self type to cast to.
     pub const subtype = .node;
 };

src/browser/html/window.zig

@@ -18,14 +18,13 @@
 
 const std = @import("std");
 
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const parser = @import("../netsurf.zig");
+const Env = @import("../env.zig").Env;
 const Page = @import("../page.zig").Page;
 
 const Navigator = @import("navigator.zig").Navigator;
-const History = @import("History.zig");
-const Navigation = @import("../navigation/Navigation.zig");
+const History = @import("history.zig").History;
 const Location = @import("location.zig").Location;
 const Crypto = @import("../crypto/crypto.zig").Crypto;
 const Console = @import("../console/console.zig").Console;
@@ -36,15 +35,15 @@ const CSSStyleDeclaration = @import("../cssom/CSSStyleDeclaration.zig");
 const Screen = @import("screen.zig").Screen;
 const domcss = @import("../dom/css.zig");
 const Css = @import("../css/css.zig").Css;
-const EventHandler = @import("../events/event.zig").EventHandler;
 
+const Function = Env.Function;
+const JsObject = Env.JsObject;
+
+const v8 = @import("v8");
 const Request = @import("../fetch/Request.zig");
 const fetchFn = @import("../fetch/fetch.zig").fetch;
 
 const storage = @import("../storage/storage.zig");
-const ErrorEvent = @import("error_event.zig").ErrorEvent;
-
-const DirectEventHandler = @import("../events/event.zig").DirectEventHandler;
 
 // https://dom.spec.whatwg.org/#interface-window-extensions
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#window
@@ -56,7 +55,8 @@ pub const Window = struct {
 
     document: *parser.DocumentHTML,
     target: []const u8 = "",
-    location: Location = .default,
+    history: History = .{},
+    location: Location = .{},
     storage_shelf: ?*storage.Shelf = null,
 
     // counter for having unique timer ids
@@ -69,10 +69,6 @@ pub const Window = struct {
     performance: Performance,
     screen: Screen = .{},
     css: Css = .{},
-    scroll_x: u32 = 0,
-    scroll_y: u32 = 0,
-    onload_callback: ?js.Function = null,
-    onpopstate_callback: ?js.Function = null,
 
     pub fn create(target: ?[]const u8, navigator: ?Navigator) !Window {
         var fbs = std.io.fixedBufferStream("");
@@ -103,28 +99,16 @@ pub const Window = struct {
         self.storage_shelf = shelf;
     }
 
-    pub fn _fetch(_: *Window, input: Request.RequestInput, options: ?Request.RequestInit, page: *Page) !js.Promise {
+    pub fn _fetch(_: *Window, input: Request.RequestInput, options: ?Request.RequestInit, page: *Page) !Env.Promise {
         return fetchFn(input, options, page);
     }
 
-    /// Returns `onload_callback`.
-    pub fn get_onload(self: *const Window) ?js.Function {
-        return self.onload_callback;
+    pub fn get_window(self: *Window) *Window {
+        return self;
     }
 
-    /// Sets `onload_callback`.
-    pub fn set_onload(self: *Window, maybe_listener: ?EventHandler.Listener, page: *Page) !void {
-        try DirectEventHandler(Window, self, "load", maybe_listener, &self.onload_callback, page.arena);
-    }
-
-    /// Returns `onpopstate_callback`.
-    pub fn get_onpopstate(self: *const Window) ?js.Function {
-        return self.onpopstate_callback;
-    }
-
-    /// Sets `onpopstate_callback`.
-    pub fn set_onpopstate(self: *Window, maybe_listener: ?EventHandler.Listener, page: *Page) !void {
-        try DirectEventHandler(Window, self, "popstate", maybe_listener, &self.onpopstate_callback, page.arena);
+    pub fn get_navigator(self: *Window) *Navigator {
+        return &self.navigator;
     }
 
     pub fn get_location(self: *Window) *Location {
@@ -132,7 +116,23 @@ pub const Window = struct {
     }
 
     pub fn set_location(_: *const Window, url: []const u8, page: *Page) !void {
-        return page.navigateFromWebAPI(url, .{ .reason = .script }, .{ .push = null });
+        return page.navigateFromWebAPI(url, .{ .reason = .script });
+    }
+
+    pub fn get_console(self: *Window) *Console {
+        return &self.console;
+    }
+
+    pub fn get_crypto(self: *Window) *Crypto {
+        return &self.crypto;
+    }
+
+    pub fn get_self(self: *Window) *Window {
+        return self;
+    }
+
+    pub fn get_parent(self: *Window) *Window {
+        return self;
     }
 
     // frames return the window itself, but accessing it via a pseudo
@@ -172,16 +172,16 @@ pub const Window = struct {
         return frames.get_length();
     }
 
+    pub fn get_top(self: *Window) *Window {
+        return self;
+    }
+
     pub fn get_document(self: *Window) ?*parser.DocumentHTML {
         return self.document;
     }
 
-    pub fn get_history(_: *Window, page: *Page) *History {
-        return &page.session.history;
-    }
-
-    pub fn get_navigation(_: *Window, page: *Page) *Navigation {
-        return &page.session.navigation;
+    pub fn get_history(self: *Window) *History {
+        return &self.history;
     }
 
     //  The interior height of the window in pixels, including the height of the horizontal scroll bar, if present.
@@ -210,11 +210,19 @@ pub const Window = struct {
         return &self.storage_shelf.?.bucket.session;
     }
 
+    pub fn get_performance(self: *Window) *Performance {
+        return &self.performance;
+    }
+
+    pub fn get_screen(self: *Window) *Screen {
+        return &self.screen;
+    }
+
     pub fn get_CSS(self: *Window) *Css {
         return &self.css;
     }
 
-    pub fn _requestAnimationFrame(self: *Window, cbk: js.Function, page: *Page) !u32 {
+    pub fn _requestAnimationFrame(self: *Window, cbk: Function, page: *Page) !u32 {
         return self.createTimeout(cbk, 5, page, .{
             .animation_frame = true,
             .name = "animationFrame",
@@ -226,11 +234,11 @@ pub const Window = struct {
         _ = self.timers.remove(id);
     }
 
-    pub fn _setTimeout(self: *Window, cbk: js.Function, delay: ?u32, params: []js.Object, page: *Page) !u32 {
+    pub fn _setTimeout(self: *Window, cbk: Function, delay: ?u32, params: []Env.JsObject, page: *Page) !u32 {
         return self.createTimeout(cbk, delay, page, .{ .args = params, .name = "setTimeout" });
     }
 
-    pub fn _setInterval(self: *Window, cbk: js.Function, delay: ?u32, params: []js.Object, page: *Page) !u32 {
+    pub fn _setInterval(self: *Window, cbk: Function, delay: ?u32, params: []Env.JsObject, page: *Page) !u32 {
         return self.createTimeout(cbk, delay, page, .{ .repeat = true, .args = params, .name = "setInterval" });
     }
 
@@ -242,22 +250,14 @@ pub const Window = struct {
         _ = self.timers.remove(id);
     }
 
-    pub fn _queueMicrotask(self: *Window, cbk: js.Function, page: *Page) !u32 {
+    pub fn _queueMicrotask(self: *Window, cbk: Function, page: *Page) !u32 {
         return self.createTimeout(cbk, 0, page, .{ .name = "queueMicrotask" });
     }
 
-    pub fn _setImmediate(self: *Window, cbk: js.Function, page: *Page) !u32 {
-        return self.createTimeout(cbk, 0, page, .{ .name = "setImmediate" });
-    }
-
-    pub fn _clearImmediate(self: *Window, id: u32) void {
-        _ = self.timers.remove(id);
-    }
-
-    pub fn _matchMedia(_: *const Window, media: js.String) !MediaQueryList {
+    pub fn _matchMedia(_: *const Window, media: []const u8, page: *Page) !MediaQueryList {
         return .{
             .matches = false, // TODO?
-            .media = media.string,
+            .media = try page.arena.dupe(u8, media),
         };
     }
 
@@ -276,33 +276,14 @@ pub const Window = struct {
         return out;
     }
 
-    pub fn _reportError(self: *Window, err: js.Object, page: *Page) !void {
-        var error_event = try ErrorEvent.constructor("error", .{
-            .@"error" = err,
-        });
-        _ = try parser.eventTargetDispatchEvent(
-            parser.toEventTarget(Window, self),
-            @as(*parser.Event, &error_event.proto),
-        );
-
-        if (parser.eventDefaultPrevented(&error_event.proto) == false) {
-            const err_string = err.toString() catch "Unknown error";
-            log.info(.user_script, "error", .{
-                .err = err_string,
-                .stack = page.stackTrace() catch "???",
-                .source = "window.reportError",
-            });
-        }
-    }
-
     const CreateTimeoutOpts = struct {
         name: []const u8,
-        args: []js.Object = &.{},
+        args: []Env.JsObject = &.{},
         repeat: bool = false,
         animation_frame: bool = false,
         low_priority: bool = false,
     };
-    fn createTimeout(self: *Window, cbk: js.Function, delay_: ?u32, page: *Page, opts: CreateTimeoutOpts) !u32 {
+    fn createTimeout(self: *Window, cbk: Function, delay_: ?u32, page: *Page, opts: CreateTimeoutOpts) !u32 {
         const delay = delay_ orelse 0;
         if (self.timers.count() > 512) {
             return error.TooManyTimeout;
@@ -322,9 +303,9 @@ pub const Window = struct {
         errdefer _ = self.timers.remove(timer_id);
 
         const args = opts.args;
-        var persisted_args: []js.Object = &.{};
+        var persisted_args: []Env.JsObject = &.{};
         if (args.len > 0) {
-            persisted_args = try page.arena.alloc(js.Object, args.len);
+            persisted_args = try page.arena.alloc(Env.JsObject, args.len);
             for (args, persisted_args) |a, *ca| {
                 ca.* = try a.persist();
             }
@@ -365,20 +346,12 @@ pub const Window = struct {
         const Opts = struct {
             top: i32,
             left: i32,
-            behavior: []const u8 = "",
+            behavior: []const u8,
         };
     };
-    pub fn _scrollTo(self: *Window, opts: ScrollToOpts, y: ?i32) !void {
-        switch (opts) {
-            .x => |x| {
-                self.scroll_x = @intCast(@max(x, 0));
-                self.scroll_y = @intCast(@max(0, y orelse 0));
-            },
-            .opts => |o| {
-                self.scroll_y = @intCast(@max(0, o.top));
-                self.scroll_x = @intCast(@max(0, o.left));
-            },
-        }
+    pub fn _scrollTo(self: *Window, opts: ScrollToOpts, y: ?u32) !void {
+        _ = opts;
+        _ = y;
 
         {
             const scroll_event = try parser.eventCreate();
@@ -402,28 +375,6 @@ pub const Window = struct {
             );
         }
     }
-    pub fn _scroll(self: *Window, opts: ScrollToOpts, y: ?i32) !void {
-        // just an alias for scrollTo
-        return self._scrollTo(opts, y);
-    }
-
-    pub fn get_scrollX(self: *const Window) u32 {
-        return self.scroll_x;
-    }
-
-    pub fn get_scrollY(self: *const Window) u32 {
-        return self.scroll_y;
-    }
-
-    pub fn get_pageXOffset(self: *const Window) u32 {
-        // just an alias for scrollX
-        return self.get_scrollX();
-    }
-
-    pub fn get_pageYOffset(self: *const Window) u32 {
-        // just an alias for scrollY
-        return self.get_scrollY();
-    }
 
     // libdom's document doesn't have a parent, which is correct, but
     // breaks the event bubbling that happens for many events from
@@ -441,18 +392,6 @@ pub const Window = struct {
         // and thus the target has already been set to the document.
         return self.base.redispatchEvent(evt);
     }
-
-    pub fn postAttach(self: *Window, js_this: js.This) !void {
-        try js_this.set("top", self, .{});
-        try js_this.set("self", self, .{});
-        try js_this.set("parent", self, .{});
-        try js_this.set("window", self, .{});
-        try js_this.set("crypto", &self.crypto, .{});
-        try js_this.set("screen", &self.screen, .{});
-        try js_this.set("console", &self.console, .{});
-        try js_this.set("navigator", &self.navigator, .{});
-        try js_this.set("performance", &self.performance, .{});
-    }
 };
 
 const TimerCallback = struct {
@@ -463,13 +402,13 @@ const TimerCallback = struct {
     repeat: ?u32,
 
     // The JavaScript callback to execute
-    cbk: js.Function,
+    cbk: Function,
 
     animation_frame: bool = false,
 
     window: *Window,
 
-    args: []js.Object = &.{},
+    args: []Env.JsObject = &.{},
 
     fn run(ctx: *anyopaque) ?u32 {
         const self: *TimerCallback = @ptrCast(@alignCast(ctx));
@@ -483,7 +422,7 @@ const TimerCallback = struct {
             return null;
         }
 
-        var result: js.Function.Result = undefined;
+        var result: Function.Result = undefined;
 
         var call: anyerror!void = undefined;
         if (self.animation_frame) {

src/browser/js/Caller.zig

@@ -1,561 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const log = @import("../../log.zig");
-const Page = @import("../page.zig").Page;
-
-const types = @import("types.zig");
-const Context = @import("Context.zig");
-
-const Allocator = std.mem.Allocator;
-const ArenaAllocator = std.heap.ArenaAllocator;
-
-const CALL_ARENA_RETAIN = 1024 * 16;
-
-// Responsible for calling Zig functions from JS invocations. This could
-// probably just contained in ExecutionWorld, but having this specific logic, which
-// is somewhat repetitive between constructors, functions, getters, etc contained
-// here does feel like it makes it cleaner.
-const Caller = @This();
-context: *Context,
-v8_context: v8.Context,
-isolate: v8.Isolate,
-call_arena: Allocator,
-
-// info is a v8.PropertyCallbackInfo or a v8.FunctionCallback
-// All we really want from it is the isolate.
-// executor = Isolate -> getCurrentContext -> getEmbedderData()
-pub fn init(info: anytype) Caller {
-    const isolate = info.getIsolate();
-    const v8_context = isolate.getCurrentContext();
-    const context: *Context = @ptrFromInt(v8_context.getEmbedderData(1).castTo(v8.BigInt).getUint64());
-
-    context.call_depth += 1;
-    return .{
-        .context = context,
-        .isolate = isolate,
-        .v8_context = v8_context,
-        .call_arena = context.call_arena,
-    };
-}
-
-pub fn deinit(self: *Caller) void {
-    const context = self.context;
-    const call_depth = context.call_depth - 1;
-
-    // Because of callbacks, calls can be nested. Because of this, we
-    // can't clear the call_arena after _every_ call. Imagine we have
-    //    arr.forEach((i) => { console.log(i); }
-    //
-    // First we call forEach. Inside of our forEach call,
-    // we call console.log. If we reset the call_arena after this call,
-    // it'll reset it for the `forEach` call after, which might still
-    // need the data.
-    //
-    // Therefore, we keep a call_depth, and only reset the call_arena
-    // when a top-level (call_depth == 0) function ends.
-    if (call_depth == 0) {
-        const arena: *ArenaAllocator = @ptrCast(@alignCast(context.call_arena.ptr));
-        _ = arena.reset(.{ .retain_with_limit = CALL_ARENA_RETAIN });
-    }
-
-    // Set this _after_ we've executed the above code, so that if the
-    // above code executes any callbacks, they aren't being executed
-    // at scope 0, which would be wrong.
-    context.call_depth = call_depth;
-}
-
-pub fn constructor(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, info: v8.FunctionCallbackInfo) !void {
-    const args = try self.getArgs(Struct, named_function, 0, info);
-    const res = @call(.auto, Struct.constructor, args);
-
-    const ReturnType = @typeInfo(@TypeOf(Struct.constructor)).@"fn".return_type orelse {
-        @compileError(@typeName(Struct) ++ " has a constructor without a return type");
-    };
-
-    const this = info.getThis();
-    if (@typeInfo(ReturnType) == .error_union) {
-        const non_error_res = res catch |err| return err;
-        _ = try self.context.mapZigInstanceToJs(this, non_error_res);
-    } else {
-        _ = try self.context.mapZigInstanceToJs(this, res);
-    }
-    info.getReturnValue().set(this);
-}
-
-pub fn method(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, info: v8.FunctionCallbackInfo) !void {
-    if (comptime isSelfReceiver(Struct, named_function) == false) {
-        return self.function(Struct, named_function, info);
-    }
-
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    var args = try self.getArgs(Struct, named_function, 1, info);
-    const zig_instance = try context.typeTaggedAnyOpaque(named_function, *types.Receiver(Struct), info.getThis());
-
-    // inject 'self' as the first parameter
-    @field(args, "0") = zig_instance;
-
-    const res = @call(.auto, func, args);
-    info.getReturnValue().set(try context.zigValueToJs(res));
-}
-
-pub fn function(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, info: v8.FunctionCallbackInfo) !void {
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    const args = try self.getArgs(Struct, named_function, 0, info);
-    const res = @call(.auto, func, args);
-    info.getReturnValue().set(try context.zigValueToJs(res));
-}
-
-pub fn getIndex(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, idx: u32, info: v8.PropertyCallbackInfo) !u8 {
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    const IndexedGet = @TypeOf(func);
-    if (@typeInfo(IndexedGet).@"fn".return_type == null) {
-        @compileError(named_function.full_name ++ " must have a return type");
-    }
-
-    var has_value = true;
-
-    var args: ParamterTypes(IndexedGet) = undefined;
-    const arg_fields = @typeInfo(@TypeOf(args)).@"struct".fields;
-    switch (arg_fields.len) {
-        0, 1, 2 => @compileError(named_function.full_name ++ " must take at least a u32 and *bool parameter"),
-        3, 4 => {
-            const zig_instance = try context.typeTaggedAnyOpaque(named_function, *types.Receiver(Struct), info.getThis());
-            comptime assertSelfReceiver(Struct, named_function);
-            @field(args, "0") = zig_instance;
-            @field(args, "1") = idx;
-            @field(args, "2") = &has_value;
-            if (comptime arg_fields.len == 4) {
-                comptime assertIsPageArg(Struct, named_function, 3);
-                @field(args, "3") = context.page;
-            }
-        },
-        else => @compileError(named_function.full_name ++ " has too many parmaters"),
-    }
-
-    const res = @call(.auto, func, args);
-    if (has_value == false) {
-        return v8.Intercepted.No;
-    }
-    info.getReturnValue().set(try context.zigValueToJs(res));
-    return v8.Intercepted.Yes;
-}
-
-pub fn getNamedIndex(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, name: v8.Name, info: v8.PropertyCallbackInfo) !u8 {
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    comptime assertSelfReceiver(Struct, named_function);
-
-    var has_value = true;
-    var args = try self.getArgs(Struct, named_function, 3, info);
-    const zig_instance = try context.typeTaggedAnyOpaque(named_function, *types.Receiver(Struct), info.getThis());
-    @field(args, "0") = zig_instance;
-    @field(args, "1") = try self.nameToString(name);
-    @field(args, "2") = &has_value;
-
-    const res = @call(.auto, func, args);
-    if (has_value == false) {
-        return v8.Intercepted.No;
-    }
-    info.getReturnValue().set(try self.context.zigValueToJs(res));
-    return v8.Intercepted.Yes;
-}
-
-pub fn setNamedIndex(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, name: v8.Name, js_value: v8.Value, info: v8.PropertyCallbackInfo) !u8 {
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    comptime assertSelfReceiver(Struct, named_function);
-
-    var has_value = true;
-    var args = try self.getArgs(Struct, named_function, 4, info);
-    const zig_instance = try context.typeTaggedAnyOpaque(named_function, *types.Receiver(Struct), info.getThis());
-    @field(args, "0") = zig_instance;
-    @field(args, "1") = try self.nameToString(name);
-    @field(args, "2") = try context.jsValueToZig(named_function, @TypeOf(@field(args, "2")), js_value);
-    @field(args, "3") = &has_value;
-
-    const res = @call(.auto, func, args);
-    return namedSetOrDeleteCall(res, has_value);
-}
-
-pub fn deleteNamedIndex(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, name: v8.Name, info: v8.PropertyCallbackInfo) !u8 {
-    const context = self.context;
-    const func = @field(Struct, named_function.name);
-    comptime assertSelfReceiver(Struct, named_function);
-
-    var has_value = true;
-    var args = try self.getArgs(Struct, named_function, 3, info);
-    const zig_instance = try context.typeTaggedAnyOpaque(named_function, *types.Receiver(Struct), info.getThis());
-    @field(args, "0") = zig_instance;
-    @field(args, "1") = try self.nameToString(name);
-    @field(args, "2") = &has_value;
-
-    const res = @call(.auto, func, args);
-    return namedSetOrDeleteCall(res, has_value);
-}
-
-fn namedSetOrDeleteCall(res: anytype, has_value: bool) !u8 {
-    if (@typeInfo(@TypeOf(res)) == .error_union) {
-        _ = try res;
-    }
-    if (has_value == false) {
-        return v8.Intercepted.No;
-    }
-    return v8.Intercepted.Yes;
-}
-
-fn nameToString(self: *Caller, name: v8.Name) ![]const u8 {
-    return self.context.valueToString(.{ .handle = name.handle }, .{});
-}
-
-fn isSelfReceiver(comptime Struct: type, comptime named_function: NamedFunction) bool {
-    return checkSelfReceiver(Struct, named_function, false);
-}
-fn assertSelfReceiver(comptime Struct: type, comptime named_function: NamedFunction) void {
-    _ = checkSelfReceiver(Struct, named_function, true);
-}
-fn checkSelfReceiver(comptime Struct: type, comptime named_function: NamedFunction, comptime fail: bool) bool {
-    const func = @field(Struct, named_function.name);
-    const params = @typeInfo(@TypeOf(func)).@"fn".params;
-    if (params.len == 0) {
-        if (fail) {
-            @compileError(named_function.full_name ++ " must have a self parameter");
-        }
-        return false;
-    }
-
-    const R = types.Receiver(Struct);
-    const first_param = params[0].type.?;
-    if (first_param != *R and first_param != *const R) {
-        if (fail) {
-            @compileError(std.fmt.comptimePrint("The first parameter to {s} must be a *{s} or *const {s}. Got: {s}", .{
-                named_function.full_name,
-                @typeName(R),
-                @typeName(R),
-                @typeName(first_param),
-            }));
-        }
-        return false;
-    }
-    return true;
-}
-
-fn assertIsPageArg(comptime Struct: type, comptime named_function: NamedFunction, index: comptime_int) void {
-    const F = @TypeOf(@field(Struct, named_function.name));
-    const param = @typeInfo(F).@"fn".params[index].type.?;
-    if (isPage(param)) {
-        return;
-    }
-    @compileError(std.fmt.comptimePrint("The {d} parameter to {s} must be a *Page or *const Page. Got: {s}", .{ index, named_function.full_name, @typeName(param) }));
-}
-
-pub fn handleError(self: *Caller, comptime Struct: type, comptime named_function: NamedFunction, err: anyerror, info: anytype) void {
-    const isolate = self.isolate;
-
-    if (comptime @import("builtin").mode == .Debug and @hasDecl(@TypeOf(info), "length")) {
-        if (log.enabled(.js, .warn)) {
-            self.logFunctionCallError(err, named_function.full_name, info);
-        }
-    }
-
-    var js_err: ?v8.Value = switch (err) {
-        error.InvalidArgument => createTypeException(isolate, "invalid argument"),
-        error.OutOfMemory => js._createException(isolate, "out of memory"),
-        error.IllegalConstructor => js._createException(isolate, "Illegal Contructor"),
-        else => blk: {
-            const func = @field(Struct, named_function.name);
-            const return_type = @typeInfo(@TypeOf(func)).@"fn".return_type orelse {
-                // void return type;
-                break :blk null;
-            };
-
-            if (@typeInfo(return_type) != .error_union) {
-                // type defines a custom exception, but this function should
-                // not fail. We failed somewhere inside of js.zig and
-                // should return the error as-is, since it isn't related
-                // to our Struct
-                break :blk null;
-            }
-
-            const function_error_set = @typeInfo(return_type).error_union.error_set;
-
-            const E = comptime getCustomException(Struct) orelse break :blk null;
-            if (function_error_set == E or isErrorSetException(E, err)) {
-                const custom_exception = E.init(self.call_arena, err, named_function.js_name) catch |init_err| {
-                    switch (init_err) {
-                        // if a custom exceptions' init wants to return a
-                        // different error, we need to think about how to
-                        // handle that failure.
-                        error.OutOfMemory => break :blk js._createException(isolate, "out of memory"),
-                    }
-                };
-                // ughh..how to handle an error here?
-                break :blk self.context.zigValueToJs(custom_exception) catch js._createException(isolate, "internal error");
-            }
-            // this error isn't part of a custom exception
-            break :blk null;
-        },
-    };
-
-    if (js_err == null) {
-        js_err = js._createException(isolate, @errorName(err));
-    }
-    const js_exception = isolate.throwException(js_err.?);
-    info.getReturnValue().setValueHandle(js_exception.handle);
-}
-
-// walk the prototype chain to see if a type declares a custom Exception
-fn getCustomException(comptime Struct: type) ?type {
-    var S = Struct;
-    while (true) {
-        if (@hasDecl(S, "Exception")) {
-            return S.Exception;
-        }
-        if (@hasDecl(S, "prototype") == false) {
-            return null;
-        }
-        // long ago, we validated that every prototype declaration
-        // is a pointer.
-        S = @typeInfo(S.prototype).pointer.child;
-    }
-}
-
-// Does the error we want to return belong to the custom exeception's ErrorSet
-fn isErrorSetException(comptime E: type, err: anytype) bool {
-    const Entry = std.meta.Tuple(&.{ []const u8, void });
-
-    const error_set = @typeInfo(E.ErrorSet).error_set.?;
-    const entries = comptime blk: {
-        var kv: [error_set.len]Entry = undefined;
-        for (error_set, 0..) |e, i| {
-            kv[i] = .{ e.name, {} };
-        }
-        break :blk kv;
-    };
-    const lookup = std.StaticStringMap(void).initComptime(entries);
-    return lookup.has(@errorName(err));
-}
-
-// If we call a method in javascript: cat.lives('nine');
-//
-// Then we'd expect a Zig function with 2 parameters: a self and the string.
-// In this case, offset == 1. Offset is always 1 for setters or methods.
-//
-// Offset is always 0 for constructors.
-//
-// For constructors, setters and methods, we can further increase offset + 1
-// if the first parameter is an instance of Page.
-//
-// Finally, if the JS function is called with _more_ parameters and
-// the last parameter in Zig is an array, we'll try to slurp the additional
-// parameters into the array.
-fn getArgs(self: *const Caller, comptime Struct: type, comptime named_function: NamedFunction, comptime offset: usize, info: anytype) !ParamterTypes(@TypeOf(@field(Struct, named_function.name))) {
-    const context = self.context;
-    const F = @TypeOf(@field(Struct, named_function.name));
-    var args: ParamterTypes(F) = undefined;
-
-    const params = @typeInfo(F).@"fn".params[offset..];
-    // Except for the constructor, the first parameter is always `self`
-    // This isn't something we'll bind from JS, so skip it.
-    const params_to_map = blk: {
-        if (params.len == 0) {
-            return args;
-        }
-
-        // If the last parameter is the Page, set it, and exclude it
-        // from our params slice, because we don't want to bind it to
-        // a JS argument
-        if (comptime isPage(params[params.len - 1].type.?)) {
-            @field(args, tupleFieldName(params.len - 1 + offset)) = self.context.page;
-            break :blk params[0 .. params.len - 1];
-        }
-
-        // If the last parameter is a special JsThis, set it, and exclude it
-        // from our params slice, because we don't want to bind it to
-        // a JS argument
-        if (comptime params[params.len - 1].type.? == js.This) {
-            @field(args, tupleFieldName(params.len - 1 + offset)) = .{ .obj = .{
-                .context = context,
-                .js_obj = info.getThis(),
-            } };
-
-            // AND the 2nd last parameter is state
-            if (params.len > 1 and comptime isPage(params[params.len - 2].type.?)) {
-                @field(args, tupleFieldName(params.len - 2 + offset)) = self.context.page;
-                break :blk params[0 .. params.len - 2];
-            }
-
-            break :blk params[0 .. params.len - 1];
-        }
-
-        // we have neither a Page nor a JsObject. All params must be
-        // bound to a JavaScript value.
-        break :blk params;
-    };
-
-    if (params_to_map.len == 0) {
-        return args;
-    }
-
-    const js_parameter_count = info.length();
-    const last_js_parameter = params_to_map.len - 1;
-    var is_variadic = false;
-
-    {
-        // This is going to get complicated. If the last Zig parameter
-        // is a slice AND the corresponding javascript parameter is
-        // NOT an an array, then we'll treat it as a variadic.
-
-        const last_parameter_type = params_to_map[params_to_map.len - 1].type.?;
-        const last_parameter_type_info = @typeInfo(last_parameter_type);
-        if (last_parameter_type_info == .pointer and last_parameter_type_info.pointer.size == .slice) {
-            const slice_type = last_parameter_type_info.pointer.child;
-            const corresponding_js_value = info.getArg(@as(u32, @intCast(last_js_parameter)));
-            if (corresponding_js_value.isArray() == false and corresponding_js_value.isTypedArray() == false and slice_type != u8) {
-                is_variadic = true;
-                if (js_parameter_count == 0) {
-                    @field(args, tupleFieldName(params_to_map.len + offset - 1)) = &.{};
-                } else if (js_parameter_count >= params_to_map.len) {
-                    const arr = try self.call_arena.alloc(last_parameter_type_info.pointer.child, js_parameter_count - params_to_map.len + 1);
-                    for (arr, last_js_parameter..) |*a, i| {
-                        const js_value = info.getArg(@as(u32, @intCast(i)));
-                        a.* = try context.jsValueToZig(named_function, slice_type, js_value);
-                    }
-                    @field(args, tupleFieldName(params_to_map.len + offset - 1)) = arr;
-                } else {
-                    @field(args, tupleFieldName(params_to_map.len + offset - 1)) = &.{};
-                }
-            }
-        }
-    }
-
-    inline for (params_to_map, 0..) |param, i| {
-        const field_index = comptime i + offset;
-        if (comptime i == params_to_map.len - 1) {
-            if (is_variadic) {
-                break;
-            }
-        }
-
-        if (comptime isPage(param.type.?)) {
-            @compileError("Page must be the last parameter (or 2nd last if there's a JsThis): " ++ named_function.full_name);
-        } else if (comptime param.type.? == js.This) {
-            @compileError("JsThis must be the last parameter: " ++ named_function.full_name);
-        } else if (i >= js_parameter_count) {
-            if (@typeInfo(param.type.?) != .optional) {
-                return error.InvalidArgument;
-            }
-            @field(args, tupleFieldName(field_index)) = null;
-        } else {
-            const js_value = info.getArg(@as(u32, @intCast(i)));
-            @field(args, tupleFieldName(field_index)) = context.jsValueToZig(named_function, param.type.?, js_value) catch {
-                return error.InvalidArgument;
-            };
-        }
-    }
-
-    return args;
-}
-
-// This is extracted to speed up compilation. When left inlined in handleError,
-// this can add as much as 10 seconds of compilation time.
-fn logFunctionCallError(self: *Caller, err: anyerror, function_name: []const u8, info: v8.FunctionCallbackInfo) void {
-    const args_dump = self.serializeFunctionArgs(info) catch "failed to serialize args";
-    log.info(.js, "function call error", .{
-        .name = function_name,
-        .err = err,
-        .args = args_dump,
-        .stack = self.context.stackTrace() catch |err1| @errorName(err1),
-    });
-}
-
-fn serializeFunctionArgs(self: *Caller, info: v8.FunctionCallbackInfo) ![]const u8 {
-    const separator = log.separator();
-    const js_parameter_count = info.length();
-
-    const context = self.context;
-    var arr: std.ArrayListUnmanaged(u8) = .{};
-    for (0..js_parameter_count) |i| {
-        const js_value = info.getArg(@intCast(i));
-        const value_string = try context.valueToDetailString(js_value);
-        const value_type = try context.jsStringToZig(try js_value.typeOf(self.isolate), .{});
-        try std.fmt.format(arr.writer(context.call_arena), "{s}{d}: {s} ({s})", .{
-            separator,
-            i + 1,
-            value_string,
-            value_type,
-        });
-    }
-    return arr.items;
-}
-
-// We want the function name, or more precisely, the "Struct.function" for
-// displaying helpful @compileError.
-// However, there's no way to get the name from a std.Builtin.Fn, so we create
-// a NamedFunction as part of our binding, and pass it around incase we need
-// to display an error
-pub const NamedFunction = struct {
-    name: []const u8,
-    js_name: []const u8,
-    full_name: []const u8,
-
-    pub fn init(comptime Struct: type, comptime name: []const u8) NamedFunction {
-        return .{
-            .name = name,
-            .js_name = if (name[0] == '_') name[1..] else name,
-            .full_name = @typeName(Struct) ++ "." ++ name,
-        };
-    }
-};
-
-// Takes a function, and returns a tuple for its argument. Used when we
-// @call a function
-fn ParamterTypes(comptime F: type) type {
-    const params = @typeInfo(F).@"fn".params;
-    var fields: [params.len]std.builtin.Type.StructField = undefined;
-
-    inline for (params, 0..) |param, i| {
-        fields[i] = .{
-            .name = tupleFieldName(i),
-            .type = param.type.?,
-            .default_value_ptr = null,
-            .is_comptime = false,
-            .alignment = @alignOf(param.type.?),
-        };
-    }
-
-    return @Type(.{ .@"struct" = .{
-        .layout = .auto,
-        .decls = &.{},
-        .fields = &fields,
-        .is_tuple = true,
-    } });
-}
-
-fn tupleFieldName(comptime i: usize) [:0]const u8 {
-    return switch (i) {
-        0 => "0",
-        1 => "1",
-        2 => "2",
-        3 => "3",
-        4 => "4",
-        5 => "5",
-        6 => "6",
-        7 => "7",
-        8 => "8",
-        9 => "9",
-        else => std.fmt.comptimePrint("{d}", .{i}),
-    };
-}
-
-fn isPage(comptime T: type) bool {
-    return T == *Page or T == *const Page;
-}
-
-fn createTypeException(isolate: v8.Isolate, msg: []const u8) v8.Value {
-    return v8.Exception.initTypeError(v8.String.initUtf8(isolate, msg));
-}

src/browser/js/Env.zig

@@ -1,539 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const log = @import("../../log.zig");
-
-const types = @import("types.zig");
-const Types = types.Types;
-const Caller = @import("Caller.zig");
-const Context = @import("Context.zig");
-const Platform = @import("Platform.zig");
-const Inspector = @import("Inspector.zig");
-const ExecutionWorld = @import("ExecutionWorld.zig");
-const NamedFunction = Caller.NamedFunction;
-
-const Allocator = std.mem.Allocator;
-const ArenaAllocator = std.heap.ArenaAllocator;
-
-// The Env maps to a V8 isolate, which represents a isolated sandbox for
-// executing JavaScript. The Env is where we'll define our V8 <-> Zig bindings,
-// and it's where we'll start ExecutionWorlds, which actually execute JavaScript.
-// The `S` parameter is arbitrary state. When we start an ExecutionWorld, an instance
-// of S must be given. This instance is available to any Zig binding.
-// The `types` parameter is a tuple of Zig structures we want to bind to V8.
-const Env = @This();
-
-allocator: Allocator,
-
-platform: *const Platform,
-
-// the global isolate
-isolate: v8.Isolate,
-
-// just kept around because we need to free it on deinit
-isolate_params: *v8.CreateParams,
-
-// Given a type, we can lookup its index in TYPE_LOOKUP and then have
-// access to its TunctionTemplate (the thing we need to create an instance
-// of it)
-// I.e.:
-// const index = @field(TYPE_LOOKUP, @typeName(type_name))
-// const template = templates[index];
-templates: [Types.len]v8.FunctionTemplate,
-
-// Given a type index (retrieved via the TYPE_LOOKUP), we can retrieve
-// the index of its prototype. Types without a prototype have their own
-// index.
-prototype_lookup: [Types.len]u16,
-
-meta_lookup: [Types.len]types.Meta,
-
-context_id: usize,
-
-const Opts = struct {};
-
-pub fn init(allocator: Allocator, platform: *const Platform, _: Opts) !*Env {
-    // var params = v8.initCreateParams();
-    var params = try allocator.create(v8.CreateParams);
-    errdefer allocator.destroy(params);
-
-    v8.c.v8__Isolate__CreateParams__CONSTRUCT(params);
-
-    params.array_buffer_allocator = v8.createDefaultArrayBufferAllocator();
-    errdefer v8.destroyArrayBufferAllocator(params.array_buffer_allocator.?);
-
-    var isolate = v8.Isolate.init(params);
-    errdefer isolate.deinit();
-
-    // This is the callback that runs whenever a module is dynamically imported.
-    isolate.setHostImportModuleDynamicallyCallback(Context.dynamicModuleCallback);
-    isolate.setPromiseRejectCallback(promiseRejectCallback);
-    isolate.setMicrotasksPolicy(v8.c.kExplicit);
-
-    isolate.enter();
-    errdefer isolate.exit();
-
-    isolate.setHostInitializeImportMetaObjectCallback(Context.metaObjectCallback);
-
-    var temp_scope: v8.HandleScope = undefined;
-    v8.HandleScope.init(&temp_scope, isolate);
-    defer temp_scope.deinit();
-
-    const env = try allocator.create(Env);
-    errdefer allocator.destroy(env);
-
-    env.* = .{
-        .context_id = 0,
-        .platform = platform,
-        .isolate = isolate,
-        .templates = undefined,
-        .allocator = allocator,
-        .isolate_params = params,
-        .meta_lookup = undefined,
-        .prototype_lookup = undefined,
-    };
-
-    // Populate our templates lookup. generateClass creates the
-    // v8.FunctionTemplate, which we store in our env.templates.
-    // The ordering doesn't matter. What matters is that, given a type
-    // we can get its index via: @field(types.LOOKUP, type_name)
-    const templates = &env.templates;
-    inline for (Types, 0..) |s, i| {
-        @setEvalBranchQuota(10_000);
-        templates[i] = v8.Persistent(v8.FunctionTemplate).init(isolate, generateClass(s.defaultValue().?, isolate)).castToFunctionTemplate();
-    }
-
-    // Above, we've created all our our FunctionTemplates. Now that we
-    // have them all, we can hook up the prototypes.
-    const meta_lookup = &env.meta_lookup;
-    inline for (Types, 0..) |s, i| {
-        const Struct = s.defaultValue().?;
-        if (@hasDecl(Struct, "prototype")) {
-            const TI = @typeInfo(Struct.prototype);
-            const proto_name = @typeName(types.Receiver(TI.pointer.child));
-            if (@hasField(types.Lookup, proto_name) == false) {
-                @compileError(std.fmt.comptimePrint("Prototype '{s}' for '{s}' is undefined", .{ proto_name, @typeName(Struct) }));
-            }
-            // Hey, look! This is our first real usage of the types.LOOKUP.
-            // Just like we said above, given a type, we can get its
-            // template index.
-
-            const proto_index = @field(types.LOOKUP, proto_name);
-            templates[i].inherit(templates[proto_index]);
-        }
-
-        // while we're here, let's populate our meta lookup
-        const subtype: ?types.Sub = if (@hasDecl(Struct, "subtype")) Struct.subtype else null;
-
-        const proto_offset = comptime blk: {
-            if (!@hasField(Struct, "proto")) {
-                break :blk 0;
-            }
-            const proto_info = std.meta.fieldInfo(Struct, .proto);
-            if (@typeInfo(proto_info.type) == .pointer) {
-                // we store the offset as a negative, to so that,
-                // when we reverse this, we know that it's
-                // behind a pointer that we need to resolve.
-                break :blk -@offsetOf(Struct, "proto");
-            }
-            break :blk @offsetOf(Struct, "proto");
-        };
-
-        meta_lookup[i] = .{
-            .index = i,
-            .subtype = subtype,
-            .proto_offset = proto_offset,
-        };
-    }
-
-    return env;
-}
-
-pub fn deinit(self: *Env) void {
-    self.isolate.exit();
-    self.isolate.deinit();
-    v8.destroyArrayBufferAllocator(self.isolate_params.array_buffer_allocator.?);
-    self.allocator.destroy(self.isolate_params);
-    self.allocator.destroy(self);
-}
-
-pub fn newInspector(self: *Env, arena: Allocator, ctx: anytype) !Inspector {
-    return Inspector.init(arena, self.isolate, ctx);
-}
-
-pub fn runMicrotasks(self: *const Env) void {
-    self.isolate.performMicrotasksCheckpoint();
-}
-
-pub fn pumpMessageLoop(self: *const Env) bool {
-    return self.platform.inner.pumpMessageLoop(self.isolate, false);
-}
-
-pub fn runIdleTasks(self: *const Env) void {
-    return self.platform.inner.runIdleTasks(self.isolate, 1);
-}
-
-pub fn newExecutionWorld(self: *Env) !ExecutionWorld {
-    return .{
-        .env = self,
-        .context = null,
-        .context_arena = ArenaAllocator.init(self.allocator),
-    };
-}
-
-// V8 doesn't immediately free memory associated with
-// a Context, it's managed by the garbage collector. We use the
-// `lowMemoryNotification` call on the isolate to encourage v8 to free
-// any contexts which have been freed.
-pub fn lowMemoryNotification(self: *Env) void {
-    var handle_scope: v8.HandleScope = undefined;
-    v8.HandleScope.init(&handle_scope, self.isolate);
-    defer handle_scope.deinit();
-    self.isolate.lowMemoryNotification();
-}
-
-pub fn dumpMemoryStats(self: *Env) void {
-    const stats = self.isolate.getHeapStatistics();
-    std.debug.print(
-        \\ Total Heap Size: {d}
-        \\ Total Heap Size Executable: {d}
-        \\ Total Physical Size: {d}
-        \\ Total Available Size: {d}
-        \\ Used Heap Size: {d}
-        \\ Heap Size Limit: {d}
-        \\ Malloced Memory: {d}
-        \\ External Memory: {d}
-        \\ Peak Malloced Memory: {d}
-        \\ Number Of Native Contexts: {d}
-        \\ Number Of Detached Contexts: {d}
-        \\ Total Global Handles Size: {d}
-        \\ Used Global Handles Size: {d}
-        \\ Zap Garbage: {any}
-        \\
-    , .{ stats.total_heap_size, stats.total_heap_size_executable, stats.total_physical_size, stats.total_available_size, stats.used_heap_size, stats.heap_size_limit, stats.malloced_memory, stats.external_memory, stats.peak_malloced_memory, stats.number_of_native_contexts, stats.number_of_detached_contexts, stats.total_global_handles_size, stats.used_global_handles_size, stats.does_zap_garbage });
-}
-
-fn promiseRejectCallback(v8_msg: v8.C_PromiseRejectMessage) callconv(.c) void {
-    const msg = v8.PromiseRejectMessage.initFromC(v8_msg);
-    const isolate = msg.getPromise().toObject().getIsolate();
-    const context = Context.fromIsolate(isolate);
-
-    const value =
-        if (msg.getValue()) |v8_value| context.valueToString(v8_value, .{}) catch |err| @errorName(err) else "no value";
-
-    log.debug(.js, "unhandled rejection", .{ .value = value });
-}
-
-// Give it a Zig struct, get back a v8.FunctionTemplate.
-// The FunctionTemplate is a bit like a struct container - it's where
-// we'll attach functions/getters/setters and where we'll "inherit" a
-// prototype type (if there is any)
-fn generateClass(comptime Struct: type, isolate: v8.Isolate) v8.FunctionTemplate {
-    const template = generateConstructor(Struct, isolate);
-    attachClass(Struct, isolate, template);
-    return template;
-}
-
-// Normally this is called from generateClass. Where generateClass creates
-// the constructor (hence, the FunctionTemplate), attachClass adds all
-// of its functions, getters, setters, ...
-// But it's extracted from generateClass because we also have 1 global
-// object (i.e. the Window), which gets attached not only to the Window
-// constructor/FunctionTemplate as normal, but also through the default
-// FunctionTemplate of the isolate (in createContext)
-pub fn attachClass(comptime Struct: type, isolate: v8.Isolate, template: v8.FunctionTemplate) void {
-    const template_proto = template.getPrototypeTemplate();
-    inline for (@typeInfo(Struct).@"struct".decls) |declaration| {
-        const name = declaration.name;
-        if (comptime name[0] == '_') {
-            switch (@typeInfo(@TypeOf(@field(Struct, name)))) {
-                .@"fn" => generateMethod(Struct, name, isolate, template_proto),
-                else => |ti| if (!comptime js.isComplexAttributeType(ti)) {
-                    generateAttribute(Struct, name, isolate, template, template_proto);
-                },
-            }
-        } else if (comptime std.mem.startsWith(u8, name, "get_")) {
-            generateProperty(Struct, name[4..], isolate, template_proto);
-        } else if (comptime std.mem.startsWith(u8, name, "static_")) {
-            generateFunction(Struct, name[7..], isolate, template);
-        }
-    }
-
-    if (@hasDecl(Struct, "get_symbol_toStringTag") == false) {
-        // If this WAS defined, then we would have created it in generateProperty.
-        // But if it isn't, we create a default one
-        const string_tag_callback = v8.FunctionTemplate.initCallback(isolate, struct {
-            fn stringTag(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-                const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-                const class_name = v8.String.initUtf8(info.getIsolate(), comptime js.classNameForStruct(Struct));
-                info.getReturnValue().set(class_name);
-            }
-        }.stringTag);
-        const key = v8.Symbol.getToStringTag(isolate).toName();
-        template_proto.setAccessorGetter(key, string_tag_callback);
-    }
-
-    generateIndexer(Struct, template_proto);
-    generateNamedIndexer(Struct, template.getInstanceTemplate());
-    generateUndetectable(Struct, template.getInstanceTemplate());
-}
-
-// Even if a struct doesn't have a `constructor` function, we still
-// `generateConstructor`, because this is how we create our
-// FunctionTemplate. Such classes exist, but they can't be instantiated
-// via `new ClassName()` - but they could, for example, be created in
-// Zig and returned from a function call, which is why we need the
-// FunctionTemplate.
-fn generateConstructor(comptime Struct: type, isolate: v8.Isolate) v8.FunctionTemplate {
-    const template = v8.FunctionTemplate.initCallback(isolate, struct {
-        fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-            const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-            var caller = Caller.init(info);
-            defer caller.deinit();
-            // See comment above. We generateConstructor on all types
-            // in order to create the FunctionTemplate, but there might
-            // not be an actual "constructor" function. So if someone
-            // does `new ClassName()` where ClassName doesn't have
-            // a constructor function, we'll return an error.
-            if (@hasDecl(Struct, "constructor") == false) {
-                const iso = caller.isolate;
-                log.warn(.js, "Illegal constructor call", .{ .name = @typeName(Struct) });
-                const js_exception = iso.throwException(js._createException(iso, "Illegal Constructor"));
-                info.getReturnValue().set(js_exception);
-                return;
-            }
-
-            // Safe to call now, because if Struct.constructor didn't
-            // exist, the above if block would have returned.
-            const named_function = comptime NamedFunction.init(Struct, "constructor");
-            caller.constructor(Struct, named_function, info) catch |err| {
-                caller.handleError(Struct, named_function, err, info);
-            };
-        }
-    }.callback);
-
-    if (comptime types.isEmpty(types.Receiver(Struct)) == false) {
-        // If the struct is empty, we won't store a Zig reference inside
-        // the JS object, so we don't need to set the internal field count
-        template.getInstanceTemplate().setInternalFieldCount(1);
-    }
-
-    const class_name = v8.String.initUtf8(isolate, comptime js.classNameForStruct(Struct));
-    template.setClassName(class_name);
-    return template;
-}
-
-fn generateMethod(comptime Struct: type, comptime name: []const u8, isolate: v8.Isolate, template_proto: v8.ObjectTemplate) void {
-    var js_name: v8.Name = undefined;
-    if (comptime std.mem.eql(u8, name, "_symbol_iterator")) {
-        js_name = v8.Symbol.getIterator(isolate).toName();
-    } else {
-        js_name = v8.String.initUtf8(isolate, name[1..]).toName();
-    }
-    const function_template = v8.FunctionTemplate.initCallback(isolate, struct {
-        fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-            const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-            var caller = Caller.init(info);
-            defer caller.deinit();
-
-            const named_function = comptime NamedFunction.init(Struct, name);
-            caller.method(Struct, named_function, info) catch |err| {
-                caller.handleError(Struct, named_function, err, info);
-            };
-        }
-    }.callback);
-    template_proto.set(js_name, function_template, v8.PropertyAttribute.None);
-}
-
-fn generateFunction(comptime Struct: type, comptime name: []const u8, isolate: v8.Isolate, template: v8.FunctionTemplate) void {
-    const js_name = v8.String.initUtf8(isolate, name).toName();
-    const function_template = v8.FunctionTemplate.initCallback(isolate, struct {
-        fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-            const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-            var caller = Caller.init(info);
-            defer caller.deinit();
-
-            const named_function = comptime NamedFunction.init(Struct, "static_" ++ name);
-            caller.function(Struct, named_function, info) catch |err| {
-                caller.handleError(Struct, named_function, err, info);
-            };
-        }
-    }.callback);
-    template.set(js_name, function_template, v8.PropertyAttribute.None);
-}
-
-fn generateAttribute(comptime Struct: type, comptime name: []const u8, isolate: v8.Isolate, template: v8.FunctionTemplate, template_proto: v8.ObjectTemplate) void {
-    const zig_value = @field(Struct, name);
-    const js_value = js.simpleZigValueToJs(isolate, zig_value, true);
-
-    const js_name = v8.String.initUtf8(isolate, name[1..]).toName();
-
-    // apply it both to the type itself
-    template.set(js_name, js_value, v8.PropertyAttribute.ReadOnly + v8.PropertyAttribute.DontDelete);
-
-    // and to instances of the type
-    template_proto.set(js_name, js_value, v8.PropertyAttribute.ReadOnly + v8.PropertyAttribute.DontDelete);
-}
-
-fn generateProperty(comptime Struct: type, comptime name: []const u8, isolate: v8.Isolate, template_proto: v8.ObjectTemplate) void {
-    var js_name: v8.Name = undefined;
-    if (comptime std.mem.eql(u8, name, "symbol_toStringTag")) {
-        js_name = v8.Symbol.getToStringTag(isolate).toName();
-    } else {
-        js_name = v8.String.initUtf8(isolate, name).toName();
-    }
-
-    const getter_callback = v8.FunctionTemplate.initCallback(isolate, struct {
-        fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-            const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-            var caller = Caller.init(info);
-            defer caller.deinit();
-
-            const named_function = comptime NamedFunction.init(Struct, "get_" ++ name);
-            caller.method(Struct, named_function, info) catch |err| {
-                caller.handleError(Struct, named_function, err, info);
-            };
-        }
-    }.callback);
-
-    const setter_name = "set_" ++ name;
-    if (@hasDecl(Struct, setter_name) == false) {
-        template_proto.setAccessorGetter(js_name, getter_callback);
-        return;
-    }
-
-    const setter_callback = v8.FunctionTemplate.initCallback(isolate, struct {
-        fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-            const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-            std.debug.assert(info.length() == 1);
-
-            var caller = Caller.init(info);
-            defer caller.deinit();
-
-            const named_function = comptime NamedFunction.init(Struct, "set_" ++ name);
-            caller.method(Struct, named_function, info) catch |err| {
-                caller.handleError(Struct, named_function, err, info);
-            };
-        }
-    }.callback);
-
-    template_proto.setAccessorGetterAndSetter(js_name, getter_callback, setter_callback);
-}
-
-fn generateIndexer(comptime Struct: type, template_proto: v8.ObjectTemplate) void {
-    if (@hasDecl(Struct, "indexed_get") == false) {
-        return;
-    }
-    const configuration = v8.IndexedPropertyHandlerConfiguration{
-        .getter = struct {
-            fn callback(idx: u32, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
-                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
-                var caller = Caller.init(info);
-                defer caller.deinit();
-
-                const named_function = comptime NamedFunction.init(Struct, "indexed_get");
-                return caller.getIndex(Struct, named_function, idx, info) catch |err| blk: {
-                    caller.handleError(Struct, named_function, err, info);
-                    break :blk v8.Intercepted.No;
-                };
-            }
-        }.callback,
-    };
-
-    // If you're trying to implement setter, read:
-    // https://groups.google.com/g/v8-users/c/8tahYBsHpgY/m/IteS7Wn2AAAJ
-    // The issue I had was
-    // (a) where to attache it: does it go on the instance_template
-    //     instead of the prototype?
-    // (b) defining the getter or query to respond with the
-    //     PropertyAttribute to indicate if the property can be set
-    template_proto.setIndexedProperty(configuration, null);
-}
-
-fn generateNamedIndexer(comptime Struct: type, template_proto: v8.ObjectTemplate) void {
-    if (@hasDecl(Struct, "named_get") == false) {
-        return;
-    }
-
-    var configuration = v8.NamedPropertyHandlerConfiguration{
-        .getter = struct {
-            fn callback(c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
-                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
-                var caller = Caller.init(info);
-                defer caller.deinit();
-
-                const named_function = comptime NamedFunction.init(Struct, "named_get");
-                return caller.getNamedIndex(Struct, named_function, .{ .handle = c_name.? }, info) catch |err| blk: {
-                    caller.handleError(Struct, named_function, err, info);
-                    break :blk v8.Intercepted.No;
-                };
-            }
-        }.callback,
-
-        // This is really cool. Without this, we'd intercept _all_ properties
-        // even those explicitly set. So, node.length for example would get routed
-        // to our `named_get`, rather than a `get_length`. This might be
-        // useful if we run into a type that we can't model properly in Zig.
-        .flags = v8.PropertyHandlerFlags.OnlyInterceptStrings | v8.PropertyHandlerFlags.NonMasking,
-    };
-
-    if (@hasDecl(Struct, "named_set")) {
-        configuration.setter = struct {
-            fn callback(c_name: ?*const v8.C_Name, c_value: ?*const v8.C_Value, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
-                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
-                var caller = Caller.init(info);
-                defer caller.deinit();
-
-                const named_function = comptime NamedFunction.init(Struct, "named_set");
-                return caller.setNamedIndex(Struct, named_function, .{ .handle = c_name.? }, .{ .handle = c_value.? }, info) catch |err| blk: {
-                    caller.handleError(Struct, named_function, err, info);
-                    break :blk v8.Intercepted.No;
-                };
-            }
-        }.callback;
-    }
-
-    if (@hasDecl(Struct, "named_delete")) {
-        configuration.deleter = struct {
-            fn callback(c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
-                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
-                var caller = Caller.init(info);
-                defer caller.deinit();
-
-                const named_function = comptime NamedFunction.init(Struct, "named_delete");
-                return caller.deleteNamedIndex(Struct, named_function, .{ .handle = c_name.? }, info) catch |err| blk: {
-                    caller.handleError(Struct, named_function, err, info);
-                    break :blk v8.Intercepted.No;
-                };
-            }
-        }.callback;
-    }
-    template_proto.setNamedProperty(configuration, null);
-}
-
-fn generateUndetectable(comptime Struct: type, template: v8.ObjectTemplate) void {
-    const has_js_call_as_function = @hasDecl(Struct, "jsCallAsFunction");
-
-    if (has_js_call_as_function) {
-        template.setCallAsFunctionHandler(struct {
-            fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
-                const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
-                var caller = Caller.init(info);
-                defer caller.deinit();
-
-                const named_function = comptime NamedFunction.init(Struct, "jsCallAsFunction");
-                caller.method(Struct, named_function, info) catch |err| {
-                    caller.handleError(Struct, named_function, err, info);
-                };
-            }
-        }.callback);
-    }
-
-    if (@hasDecl(Struct, "mark_as_undetectable") and Struct.mark_as_undetectable) {
-        if (!has_js_call_as_function) {
-            @compileError(@typeName(Struct) ++ ": mark_as_undetectable required jsCallAsFunction to be defined. This is a hard-coded requirement in V8, because mark_as_undetectable only exists for HTMLAllCollection which is also callable.");
-        }
-        template.markAsUndetectable();
-    }
-}

src/browser/js/ExecutionWorld.zig

@@ -1,251 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const log = @import("../../log.zig");
-const Page = @import("../page.zig").Page;
-const ScriptManager = @import("../ScriptManager.zig");
-
-const types = @import("types.zig");
-const Types = types.Types;
-const Env = @import("Env.zig");
-const Context = @import("Context.zig");
-
-const ArenaAllocator = std.heap.ArenaAllocator;
-
-const CONTEXT_ARENA_RETAIN = 1024 * 64;
-
-// ExecutionWorld closely models a JS World.
-// https://chromium.googlesource.com/chromium/src/+/master/third_party/blink/renderer/bindings/core/v8/V8BindingDesign.md#World
-// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/scripting/ExecutionWorld
-const ExecutionWorld = @This();
-env: *Env,
-
-// Arena whose lifetime is for a single page load. Where
-// the call_arena lives for a single function call, the context_arena
-// lives for the lifetime of the entire page. The allocator will be
-// owned by the Context, but the arena itself is owned by the ExecutionWorld
-// so that we can re-use it from context to context.
-context_arena: ArenaAllocator,
-
-// Currently a context maps to a Browser's Page. Here though, it's only a
-// mechanism to organization page-specific memory. The ExecutionWorld
-// does all the work, but having all page-specific data structures
-// grouped together helps keep things clean.
-context: ?Context = null,
-
-// no init, must be initialized via env.newExecutionWorld()
-
-pub fn deinit(self: *ExecutionWorld) void {
-    if (self.context != null) {
-        self.removeContext();
-    }
-
-    self.context_arena.deinit();
-}
-
-// Only the top Context in the Main ExecutionWorld should hold a handle_scope.
-// A v8.HandleScope is like an arena. Once created, any "Local" that
-// v8 creates will be released (or at least, releasable by the v8 GC)
-// when the handle_scope is freed.
-// We also maintain our own "context_arena" which allows us to have
-// all page related memory easily managed.
-pub fn createContext(self: *ExecutionWorld, page: *Page, enter: bool, global_callback: ?js.GlobalMissingCallback) !*Context {
-    std.debug.assert(self.context == null);
-
-    const env = self.env;
-    const isolate = env.isolate;
-    const Global = @TypeOf(page.window);
-    const templates = &self.env.templates;
-
-    var v8_context: v8.Context = blk: {
-        var temp_scope: v8.HandleScope = undefined;
-        v8.HandleScope.init(&temp_scope, isolate);
-        defer temp_scope.deinit();
-
-        const js_global = v8.FunctionTemplate.initDefault(isolate);
-        Env.attachClass(Global, isolate, js_global);
-
-        const global_template = js_global.getInstanceTemplate();
-        global_template.setInternalFieldCount(1);
-
-        // Configure the missing property callback on the global
-        // object.
-        if (global_callback != null) {
-            const configuration = v8.NamedPropertyHandlerConfiguration{
-                .getter = struct {
-                    fn callback(c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
-                        const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
-                        const context = Context.fromIsolate(info.getIsolate());
-
-                        const property = context.valueToString(.{ .handle = c_name.? }, .{}) catch "???";
-                        if (context.global_callback.?.missing(property, context)) {
-                            return v8.Intercepted.Yes;
-                        }
-                        return v8.Intercepted.No;
-                    }
-                }.callback,
-                .flags = v8.PropertyHandlerFlags.NonMasking | v8.PropertyHandlerFlags.OnlyInterceptStrings,
-            };
-            global_template.setNamedProperty(configuration, null);
-        }
-
-        // All the FunctionTemplates that we created and setup in Env.init
-        // are now going to get associated with our global instance.
-        inline for (Types, 0..) |s, i| {
-            const Struct = s.defaultValue().?;
-            const class_name = v8.String.initUtf8(isolate, comptime js.classNameForStruct(Struct));
-            global_template.set(class_name.toName(), templates[i], v8.PropertyAttribute.None);
-        }
-
-        // The global object (Window) has already been hooked into the v8
-        // engine when the Env was initialized - like every other type.
-        // But the V8 global is its own FunctionTemplate instance so even
-        // though it's also a Window, we need to set the prototype for this
-        // specific instance of the the Window.
-        if (@hasDecl(Global, "prototype")) {
-            const proto_type = types.Receiver(@typeInfo(Global.prototype).pointer.child);
-            const proto_name = @typeName(proto_type);
-            const proto_index = @field(types.LOOKUP, proto_name);
-            js_global.inherit(templates[proto_index]);
-        }
-
-        const context_local = v8.Context.init(isolate, global_template, null);
-        const v8_context = v8.Persistent(v8.Context).init(isolate, context_local).castToContext();
-        v8_context.enter();
-        errdefer if (enter) v8_context.exit();
-        defer if (!enter) v8_context.exit();
-
-        // This shouldn't be necessary, but it is:
-        // https://groups.google.com/g/v8-users/c/qAQQBmbi--8
-        // TODO: see if newer V8 engines have a way around this.
-        inline for (Types, 0..) |s, i| {
-            const Struct = s.defaultValue().?;
-
-            if (@hasDecl(Struct, "prototype")) {
-                const proto_type = types.Receiver(@typeInfo(Struct.prototype).pointer.child);
-                const proto_name = @typeName(proto_type);
-                if (@hasField(types.Lookup, proto_name) == false) {
-                    @compileError("Type '" ++ @typeName(Struct) ++ "' defines an unknown prototype: " ++ proto_name);
-                }
-
-                const proto_index = @field(types.LOOKUP, proto_name);
-                const proto_obj = templates[proto_index].getFunction(v8_context).toObject();
-
-                const self_obj = templates[i].getFunction(v8_context).toObject();
-                _ = self_obj.setPrototype(v8_context, proto_obj);
-            }
-        }
-        break :blk v8_context;
-    };
-
-    // For a Page we only create one HandleScope, it is stored in the main World (enter==true). A page can have multple contexts, 1 for each World.
-    // The main Context that enters and holds the HandleScope should therefore always be created first. Following other worlds for this page
-    // like isolated Worlds, will thereby place their objects on the main page's HandleScope. Note: In the furure the number of context will multiply multiple frames support
-    var handle_scope: ?v8.HandleScope = null;
-    if (enter) {
-        handle_scope = @as(v8.HandleScope, undefined);
-        v8.HandleScope.init(&handle_scope.?, isolate);
-    }
-    errdefer if (enter) handle_scope.?.deinit();
-
-    {
-        // If we want to overwrite the built-in console, we have to
-        // delete the built-in one.
-        const js_obj = v8_context.getGlobal();
-        const console_key = v8.String.initUtf8(isolate, "console");
-        if (js_obj.deleteValue(v8_context, console_key) == false) {
-            return error.ConsoleDeleteError;
-        }
-    }
-    const context_id = env.context_id;
-    env.context_id = context_id + 1;
-
-    self.context = Context{
-        .page = page,
-        .id = context_id,
-        .isolate = isolate,
-        .v8_context = v8_context,
-        .templates = &env.templates,
-        .meta_lookup = &env.meta_lookup,
-        .handle_scope = handle_scope,
-        .script_manager = &page.script_manager,
-        .call_arena = page.call_arena,
-        .arena = self.context_arena.allocator(),
-        .global_callback = global_callback,
-    };
-
-    var context = &self.context.?;
-    {
-        // Store a pointer to our context inside the v8 context so that, given
-        // a v8 context, we can get our context out
-        const data = isolate.initBigIntU64(@intCast(@intFromPtr(context)));
-        v8_context.setEmbedderData(1, data);
-    }
-
-    // Custom exception
-    // NOTE: there is no way in v8 to subclass the Error built-in type
-    // TODO: this is an horrible hack
-    inline for (Types) |s| {
-        const Struct = s.defaultValue().?;
-        if (@hasDecl(Struct, "ErrorSet")) {
-            const script = comptime js.classNameForStruct(Struct) ++ ".prototype.__proto__ = Error.prototype";
-            _ = try context.exec(script, "errorSubclass");
-        }
-    }
-
-    // Primitive attributes are set directly on the FunctionTemplate
-    // when we setup the environment. But we cannot set more complex
-    // types (v8 will crash).
-    //
-    // Plus, just to create more complex types, we always need a
-    // context, i.e. an Array has to have a Context to exist.
-    //
-    // As far as I can tell, getting the FunctionTemplate's object
-    // and setting values directly on it, for each context, is the
-    // way to do this.
-    inline for (Types, 0..) |s, i| {
-        const Struct = s.defaultValue().?;
-        inline for (@typeInfo(Struct).@"struct".decls) |declaration| {
-            const name = declaration.name;
-            if (comptime name[0] == '_') {
-                const value = @field(Struct, name);
-
-                if (comptime js.isComplexAttributeType(@typeInfo(@TypeOf(value)))) {
-                    const js_obj = templates[i].getFunction(v8_context).toObject();
-                    const js_name = v8.String.initUtf8(isolate, name[1..]).toName();
-                    const js_val = try context.zigValueToJs(value);
-                    if (!js_obj.setValue(v8_context, js_name, js_val)) {
-                        log.fatal(.app, "set class attribute", .{
-                            .@"struct" = @typeName(Struct),
-                            .name = name,
-                        });
-                    }
-                }
-            }
-        }
-    }
-
-    try context.setupGlobal();
-    return context;
-}
-
-pub fn removeContext(self: *ExecutionWorld) void {
-    // Force running the micro task to drain the queue before reseting the
-    // context arena.
-    // Tasks in the queue are relying to the arena memory could be present in
-    // the queue. Running them later could lead to invalid memory accesses.
-    self.env.runMicrotasks();
-
-    self.context.?.deinit();
-    self.context = null;
-    _ = self.context_arena.reset(.{ .retain_with_limit = CONTEXT_ARENA_RETAIN });
-}
-
-pub fn terminateExecution(self: *const ExecutionWorld) void {
-    self.env.isolate.terminateExecution();
-}
-
-pub fn resumeExecution(self: *const ExecutionWorld) void {
-    self.env.isolate.cancelTerminateExecution();
-}

src/browser/js/Function.zig

@@ -1,144 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Caller = @import("Caller.zig");
-const Context = @import("Context.zig");
-const PersistentFunction = v8.Persistent(v8.Function);
-
-const Allocator = std.mem.Allocator;
-
-const Function = @This();
-
-id: usize,
-context: *js.Context,
-this: ?v8.Object = null,
-func: PersistentFunction,
-
-pub const Result = struct {
-    stack: ?[]const u8,
-    exception: []const u8,
-};
-
-pub fn getName(self: *const Function, allocator: Allocator) ![]const u8 {
-    const name = self.func.castToFunction().getName();
-    return self.context.valueToString(name, .{ .allocator = allocator });
-}
-
-pub fn setName(self: *const Function, name: []const u8) void {
-    const v8_name = v8.String.initUtf8(self.context.isolate, name);
-    self.func.castToFunction().setName(v8_name);
-}
-
-pub fn withThis(self: *const Function, value: anytype) !Function {
-    const this_obj = if (@TypeOf(value) == js.Object)
-        value.js_obj
-    else
-        (try self.context.zigValueToJs(value)).castTo(v8.Object);
-
-    return .{
-        .id = self.id,
-        .this = this_obj,
-        .func = self.func,
-        .context = self.context,
-    };
-}
-
-pub fn newInstance(self: *const Function, result: *Result) !js.Object {
-    const context = self.context;
-
-    var try_catch: js.TryCatch = undefined;
-    try_catch.init(context);
-    defer try_catch.deinit();
-
-    // This creates a new instance using this Function as a constructor.
-    // This returns a generic Object
-    const js_obj = self.func.castToFunction().initInstance(context.v8_context, &.{}) orelse {
-        if (try_catch.hasCaught()) {
-            const allocator = context.call_arena;
-            result.stack = try_catch.stack(allocator) catch null;
-            result.exception = (try_catch.exception(allocator) catch "???") orelse "???";
-        } else {
-            result.stack = null;
-            result.exception = "???";
-        }
-        return error.JsConstructorFailed;
-    };
-
-    return .{
-        .context = context,
-        .js_obj = js_obj,
-    };
-}
-
-pub fn call(self: *const Function, comptime T: type, args: anytype) !T {
-    return self.callWithThis(T, self.getThis(), args);
-}
-
-pub fn tryCall(self: *const Function, comptime T: type, args: anytype, result: *Result) !T {
-    return self.tryCallWithThis(T, self.getThis(), args, result);
-}
-
-pub fn tryCallWithThis(self: *const Function, comptime T: type, this: anytype, args: anytype, result: *Result) !T {
-    var try_catch: js.TryCatch = undefined;
-    try_catch.init(self.context);
-    defer try_catch.deinit();
-
-    return self.callWithThis(T, this, args) catch |err| {
-        if (try_catch.hasCaught()) {
-            const allocator = self.context.call_arena;
-            result.stack = try_catch.stack(allocator) catch null;
-            result.exception = (try_catch.exception(allocator) catch @errorName(err)) orelse @errorName(err);
-        } else {
-            result.stack = null;
-            result.exception = @errorName(err);
-        }
-        return err;
-    };
-}
-
-pub fn callWithThis(self: *const Function, comptime T: type, this: anytype, args: anytype) !T {
-    const context = self.context;
-
-    const js_this = try context.valueToExistingObject(this);
-
-    const aargs = if (comptime @typeInfo(@TypeOf(args)) == .null) struct {}{} else args;
-
-    const js_args: []const v8.Value = switch (@typeInfo(@TypeOf(aargs))) {
-        .@"struct" => |s| blk: {
-            const fields = s.fields;
-            var js_args: [fields.len]v8.Value = undefined;
-            inline for (fields, 0..) |f, i| {
-                js_args[i] = try context.zigValueToJs(@field(aargs, f.name));
-            }
-            const cargs: [fields.len]v8.Value = js_args;
-            break :blk &cargs;
-        },
-        .pointer => blk: {
-            var values = try context.call_arena.alloc(v8.Value, args.len);
-            for (args, 0..) |a, i| {
-                values[i] = try context.zigValueToJs(a);
-            }
-            break :blk values;
-        },
-        else => @compileError("JS Function called with invalid paremter type"),
-    };
-
-    const result = self.func.castToFunction().call(context.v8_context, js_this, js_args);
-    if (result == null) {
-        return error.JSExecCallback;
-    }
-
-    if (@typeInfo(T) == .void) return {};
-    const named_function = comptime Caller.NamedFunction.init(T, "callResult");
-    return context.jsValueToZig(named_function, T, result.?);
-}
-
-fn getThis(self: *const Function) v8.Object {
-    return self.this orelse self.context.v8_context.getGlobal();
-}
-
-pub fn src(self: *const Function) ![]const u8 {
-    const value = self.func.castToFunction().toValue();
-    return self.context.valueToString(value, .{});
-}

src/browser/js/Inspector.zig

@@ -1,125 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Context = @import("Context.zig");
-
-const Allocator = std.mem.Allocator;
-
-const Inspector = @This();
-
-pub const RemoteObject = v8.RemoteObject;
-
-isolate: v8.Isolate,
-inner: *v8.Inspector,
-session: v8.InspectorSession,
-
-// We expect allocator to be an arena
-pub fn init(allocator: Allocator, isolate: v8.Isolate, ctx: anytype) !Inspector {
-    const ContextT = @TypeOf(ctx);
-
-    const InspectorContainer = switch (@typeInfo(ContextT)) {
-        .@"struct" => ContextT,
-        .pointer => |ptr| ptr.child,
-        .void => NoopInspector,
-        else => @compileError("invalid context type"),
-    };
-
-    // If necessary, turn a void context into something we can safely ptrCast
-    const safe_context: *anyopaque = if (ContextT == void) @ptrCast(@constCast(&{})) else ctx;
-
-    const channel = v8.InspectorChannel.init(safe_context, InspectorContainer.onInspectorResponse, InspectorContainer.onInspectorEvent, isolate);
-
-    const client = v8.InspectorClient.init();
-
-    const inner = try allocator.create(v8.Inspector);
-    v8.Inspector.init(inner, client, channel, isolate);
-    return .{ .inner = inner, .isolate = isolate, .session = inner.connect() };
-}
-
-pub fn deinit(self: *const Inspector) void {
-    self.session.deinit();
-    self.inner.deinit();
-}
-
-pub fn send(self: *const Inspector, msg: []const u8) void {
-    // Can't assume the main Context exists (with its HandleScope)
-    // available when doing this. Pages (and thus the HandleScope)
-    // comes and goes, but CDP can keep sending messages.
-    const isolate = self.isolate;
-    var temp_scope: v8.HandleScope = undefined;
-    v8.HandleScope.init(&temp_scope, isolate);
-    defer temp_scope.deinit();
-
-    self.session.dispatchProtocolMessage(isolate, msg);
-}
-
-// From CDP docs
-// https://chromedevtools.github.io/devtools-protocol/tot/Runtime/#type-ExecutionContextDescription
-// ----
-// - name: Human readable name describing given context.
-// - origin: Execution context origin (ie. URL who initialised the request)
-// - auxData: Embedder-specific auxiliary data likely matching
-// {isDefault: boolean, type: 'default'|'isolated'|'worker', frameId: string}
-// - is_default_context: Whether the execution context is default, should match the auxData
-pub fn contextCreated(
-    self: *const Inspector,
-    context: *const Context,
-    name: []const u8,
-    origin: []const u8,
-    aux_data: ?[]const u8,
-    is_default_context: bool,
-) void {
-    self.inner.contextCreated(context.v8_context, name, origin, aux_data, is_default_context);
-}
-
-// Retrieves the RemoteObject for a given value.
-// The value is loaded through the ExecutionWorld's mapZigInstanceToJs function,
-// just like a method return value. Therefore, if we've mapped this
-// value before, we'll get the existing JS PersistedObject and if not
-// we'll create it and track it for cleanup when the context ends.
-pub fn getRemoteObject(
-    self: *const Inspector,
-    context: *Context,
-    group: []const u8,
-    value: anytype,
-) !RemoteObject {
-    const js_value = try context.zigValueToJs(value);
-
-    // We do not want to expose this as a parameter for now
-    const generate_preview = false;
-    return self.session.wrapObject(
-        context.isolate,
-        context.v8_context,
-        js_value,
-        group,
-        generate_preview,
-    );
-}
-
-// Gets a value by object ID regardless of which context it is in.
-pub fn getNodePtr(self: *const Inspector, allocator: Allocator, object_id: []const u8) !?*anyopaque {
-    const unwrapped = try self.session.unwrapObject(allocator, object_id);
-    // The values context and groupId are not used here
-    const toa = getTaggedAnyOpaque(unwrapped.value) orelse return null;
-    if (toa.subtype == null or toa.subtype != .node) return error.ObjectIdIsNotANode;
-    return toa.ptr;
-}
-
-const NoopInspector = struct {
-    pub fn onInspectorResponse(_: *anyopaque, _: u32, _: []const u8) void {}
-    pub fn onInspectorEvent(_: *anyopaque, _: []const u8) void {}
-};
-
-pub fn getTaggedAnyOpaque(value: v8.Value) ?*js.TaggedAnyOpaque {
-    if (value.isObject() == false) {
-        return null;
-    }
-    const obj = value.castTo(v8.Object);
-    if (obj.internalFieldCount() == 0) {
-        return null;
-    }
-
-    const external_data = obj.getInternalField(0).castTo(v8.External).get().?;
-    return @ptrCast(@alignCast(external_data));
-}

src/browser/js/Object.zig

@@ -1,149 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Caller = @import("Caller.zig");
-const Context = @import("Context.zig");
-const PersistentObject = v8.Persistent(v8.Object);
-
-const Allocator = std.mem.Allocator;
-
-const Object = @This();
-js_obj: v8.Object,
-context: *js.Context,
-
-pub const SetOpts = packed struct(u32) {
-    READ_ONLY: bool = false,
-    DONT_ENUM: bool = false,
-    DONT_DELETE: bool = false,
-    _: u29 = 0,
-};
-pub fn setIndex(self: Object, index: u32, value: anytype, opts: SetOpts) !void {
-    @setEvalBranchQuota(10000);
-    const key = switch (index) {
-        inline 0...20 => |i| std.fmt.comptimePrint("{d}", .{i}),
-        else => try std.fmt.allocPrint(self.context.arena, "{d}", .{index}),
-    };
-    return self.set(key, value, opts);
-}
-
-pub fn set(self: Object, key: []const u8, value: anytype, opts: SetOpts) error{ FailedToSet, OutOfMemory }!void {
-    const context = self.context;
-
-    const js_key = v8.String.initUtf8(context.isolate, key);
-    const js_value = try context.zigValueToJs(value);
-
-    const res = self.js_obj.defineOwnProperty(context.v8_context, js_key.toName(), js_value, @bitCast(opts)) orelse false;
-    if (!res) {
-        return error.FailedToSet;
-    }
-}
-
-pub fn get(self: Object, key: []const u8) !js.Value {
-    const context = self.context;
-    const js_key = v8.String.initUtf8(context.isolate, key);
-    const js_val = try self.js_obj.getValue(context.v8_context, js_key);
-    return context.createValue(js_val);
-}
-
-pub fn isTruthy(self: Object) bool {
-    const js_value = self.js_obj.toValue();
-    return js_value.toBool(self.context.isolate);
-}
-
-pub fn toString(self: Object) ![]const u8 {
-    const js_value = self.js_obj.toValue();
-    return self.context.valueToString(js_value, .{});
-}
-
-pub fn toDetailString(self: Object) ![]const u8 {
-    const js_value = self.js_obj.toValue();
-    return self.context.valueToDetailString(js_value);
-}
-
-pub fn format(self: Object, comptime _: []const u8, _: std.fmt.FormatOptions, writer: anytype) !void {
-    return writer.writeAll(try self.toString());
-}
-
-pub fn toJson(self: Object, allocator: Allocator) ![]u8 {
-    const json_string = try v8.Json.stringify(self.context.v8_context, self.js_obj.toValue(), null);
-    const str = try self.context.jsStringToZig(json_string, .{ .allocator = allocator });
-    return str;
-}
-
-pub fn persist(self: Object) !Object {
-    var context = self.context;
-    const js_obj = self.js_obj;
-
-    const persisted = PersistentObject.init(context.isolate, js_obj);
-    try context.js_object_list.append(context.arena, persisted);
-
-    return .{
-        .context = context,
-        .js_obj = persisted.castToObject(),
-    };
-}
-
-pub fn getFunction(self: Object, name: []const u8) !?js.Function {
-    if (self.isNullOrUndefined()) {
-        return null;
-    }
-    const context = self.context;
-
-    const js_name = v8.String.initUtf8(context.isolate, name);
-
-    const js_value = try self.js_obj.getValue(context.v8_context, js_name.toName());
-    if (!js_value.isFunction()) {
-        return null;
-    }
-    return try context.createFunction(js_value);
-}
-
-pub fn isNull(self: Object) bool {
-    return self.js_obj.toValue().isNull();
-}
-
-pub fn isUndefined(self: Object) bool {
-    return self.js_obj.toValue().isUndefined();
-}
-
-pub fn triState(self: Object, comptime Struct: type, comptime name: []const u8, comptime T: type) !TriState(T) {
-    if (self.isNull()) {
-        return .{ .null = {} };
-    }
-    if (self.isUndefined()) {
-        return .{ .undefined = {} };
-    }
-    return .{ .value = try self.toZig(Struct, name, T) };
-}
-
-pub fn isNullOrUndefined(self: Object) bool {
-    return self.js_obj.toValue().isNullOrUndefined();
-}
-
-pub fn nameIterator(self: Object) js.ValueIterator {
-    const context = self.context;
-    const js_obj = self.js_obj;
-
-    const array = js_obj.getPropertyNames(context.v8_context);
-    const count = array.length();
-
-    return .{
-        .count = count,
-        .context = context,
-        .js_obj = array.castTo(v8.Object),
-    };
-}
-
-pub fn toZig(self: Object, comptime Struct: type, comptime name: []const u8, comptime T: type) !T {
-    const named_function = comptime Caller.NamedFunction.init(Struct, name);
-    return self.context.jsValueToZig(named_function, T, self.js_obj.toValue());
-}
-
-pub fn TriState(comptime T: type) type {
-    return union(enum) {
-        null: void,
-        undefined: void,
-        value: T,
-    };
-}

src/browser/js/Platform.zig

@@ -1,21 +0,0 @@
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Platform = @This();
-inner: v8.Platform,
-
-pub fn init() !Platform {
-    if (v8.initV8ICU() == false) {
-        return error.FailedToInitializeICU;
-    }
-    const platform = v8.Platform.initDefault(0, true);
-    v8.initV8Platform(platform);
-    v8.initV8();
-    return .{ .inner = platform };
-}
-
-pub fn deinit(self: Platform) void {
-    _ = v8.deinitV8();
-    v8.deinitV8Platform();
-    self.inner.deinit();
-}

src/browser/js/This.zig

@@ -1,25 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Allocator = std.mem.Allocator;
-
-// This only exists so that we know whether a function wants the opaque
-// JS argument (js.Object), or if it wants the receiver as an opaque
-// value.
-// js.Object is normally used when a method wants an opaque JS object
-// that it'll pass into a callback.
-// This is used when the function wants to do advanced manipulation
-// of the v8.Object bound to the instance. For example, postAttach is an
-// example of using This.
-
-const This = @This();
-obj: js.Object,
-
-pub fn setIndex(self: This, index: u32, value: anytype, opts: js.Object.SetOpts) !void {
-    return self.obj.setIndex(index, value, opts);
-}
-
-pub fn set(self: This, key: []const u8, value: anytype, opts: js.Object.SetOpts) !void {
-    return self.obj.set(key, value, opts);
-}

src/browser/js/TryCatch.zig

@@ -1,64 +0,0 @@
-const std = @import("std");
-const js = @import("js.zig");
-const v8 = js.v8;
-
-const Allocator = std.mem.Allocator;
-
-const TryCatch = @This();
-
-inner: v8.TryCatch,
-context: *const js.Context,
-
-pub fn init(self: *TryCatch, context: *const js.Context) void {
-    self.context = context;
-    self.inner.init(context.isolate);
-}
-
-pub fn hasCaught(self: TryCatch) bool {
-    return self.inner.hasCaught();
-}
-
-// the caller needs to deinit the string returned
-pub fn exception(self: TryCatch, allocator: Allocator) !?[]const u8 {
-    const msg = self.inner.getException() orelse return null;
-    return try self.context.valueToString(msg, .{ .allocator = allocator });
-}
-
-// the caller needs to deinit the string returned
-pub fn stack(self: TryCatch, allocator: Allocator) !?[]const u8 {
-    const context = self.context;
-    const s = self.inner.getStackTrace(context.v8_context) orelse return null;
-    return try context.valueToString(s, .{ .allocator = allocator });
-}
-
-// the caller needs to deinit the string returned
-pub fn sourceLine(self: TryCatch, allocator: Allocator) !?[]const u8 {
-    const context = self.context;
-    const msg = self.inner.getMessage() orelse return null;
-    const sl = msg.getSourceLine(context.v8_context) orelse return null;
-    return try context.jsStringToZig(sl, .{ .allocator = allocator });
-}
-
-pub fn sourceLineNumber(self: TryCatch) ?u32 {
-    const context = self.context;
-    const msg = self.inner.getMessage() orelse return null;
-    return msg.getLineNumber(context.v8_context);
-}
-
-// a shorthand method to return either the entire stack message
-// or just the exception message
-// - in Debug mode return the stack if available
-// - otherwise return the exception if available
-// the caller needs to deinit the string returned
-pub fn err(self: TryCatch, allocator: Allocator) !?[]const u8 {
-    if (comptime @import("builtin").mode == .Debug) {
-        if (try self.stack(allocator)) |msg| {
-            return msg;
-        }
-    }
-    return try self.exception(allocator);
-}
-
-pub fn deinit(self: *TryCatch) void {
-    self.inner.deinit();
-}

src/browser/js/js.zig

@@ -1,504 +0,0 @@
-// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-pub const v8 = @import("v8");
-
-const types = @import("types.zig");
-const log = @import("../../log.zig");
-const Page = @import("../page.zig").Page;
-
-const Allocator = std.mem.Allocator;
-
-pub const Env = @import("Env.zig");
-pub const ExecutionWorld = @import("ExecutionWorld.zig");
-pub const Context = @import("Context.zig");
-pub const Inspector = @import("Inspector.zig");
-
-// TODO: Is "This" really necessary?
-pub const This = @import("This.zig");
-pub const Object = @import("Object.zig");
-pub const TryCatch = @import("TryCatch.zig");
-pub const Function = @import("Function.zig");
-
-const Caller = @import("Caller.zig");
-const NamedFunction = Context.NamedFunction;
-
-// If a function returns a []i32, should that map to a plain-old
-// JavaScript array, or a Int32Array? It's ambiguous. By default, we'll
-// map arrays/slices to the JavaScript arrays. If you want a TypedArray
-// wrap it in this.
-// Also, this type has nothing to do with the Env. But we place it here
-// for consistency. Want a callback? Env.Callback. Want a JsObject?
-// Env.JsObject. Want a TypedArray? Env.TypedArray.
-pub fn TypedArray(comptime T: type) type {
-    return struct {
-        pub const _TYPED_ARRAY_ID_KLUDGE = true;
-
-        values: []const T,
-
-        pub fn dupe(self: TypedArray(T), allocator: Allocator) !TypedArray(T) {
-            return .{ .values = try allocator.dupe(T, self.values) };
-        }
-    };
-}
-
-pub const PromiseResolver = struct {
-    context: *Context,
-    resolver: v8.PromiseResolver,
-
-    pub fn promise(self: PromiseResolver) Promise {
-        return self.resolver.getPromise();
-    }
-
-    pub fn resolve(self: PromiseResolver, value: anytype) !void {
-        const context = self.context;
-        const js_value = try context.zigValueToJs(value);
-
-        // resolver.resolve will return null if the promise isn't pending
-        const ok = self.resolver.resolve(context.v8_context, js_value) orelse return;
-        if (!ok) {
-            return error.FailedToResolvePromise;
-        }
-    }
-
-    pub fn reject(self: PromiseResolver, value: anytype) !void {
-        const context = self.context;
-        const js_value = try context.zigValueToJs(value);
-
-        // resolver.reject will return null if the promise isn't pending
-        const ok = self.resolver.reject(context.v8_context, js_value) orelse return;
-        if (!ok) {
-            return error.FailedToRejectPromise;
-        }
-    }
-};
-
-pub const PersistentPromiseResolver = struct {
-    context: *Context,
-    resolver: v8.Persistent(v8.PromiseResolver),
-
-    pub fn deinit(self: *PersistentPromiseResolver) void {
-        self.resolver.deinit();
-    }
-
-    pub fn promise(self: PersistentPromiseResolver) Promise {
-        return self.resolver.castToPromiseResolver().getPromise();
-    }
-
-    pub fn resolve(self: PersistentPromiseResolver, value: anytype) !void {
-        const context = self.context;
-        const js_value = try context.zigValueToJs(value);
-
-        // resolver.resolve will return null if the promise isn't pending
-        const ok = self.resolver.castToPromiseResolver().resolve(context.v8_context, js_value) orelse return;
-        if (!ok) {
-            return error.FailedToResolvePromise;
-        }
-    }
-
-    pub fn reject(self: PersistentPromiseResolver, value: anytype) !void {
-        const context = self.context;
-        const js_value = try context.zigValueToJs(value);
-
-        // resolver.reject will return null if the promise isn't pending
-        const ok = self.resolver.castToPromiseResolver().reject(context.v8_context, js_value) orelse return;
-        if (!ok) {
-            return error.FailedToRejectPromise;
-        }
-    }
-};
-
-pub const Promise = v8.Promise;
-
-// When doing jsValueToZig, string ([]const u8) are managed by the
-// call_arena. That means that if the API wants to persist the string
-// (which is relatively common), it needs to dupe it again.
-// If the parameter is an Env.String rather than a []const u8, then
-// the page's arena will be used (rather than the call arena).
-pub const String = struct {
-    string: []const u8,
-};
-
-pub const Exception = struct {
-    inner: v8.Value,
-    context: *const Context,
-
-    // the caller needs to deinit the string returned
-    pub fn exception(self: Exception, allocator: Allocator) ![]const u8 {
-        return self.context.valueToString(self.inner, .{ .allocator = allocator });
-    }
-};
-
-pub const Value = struct {
-    value: v8.Value,
-    context: *const Context,
-
-    // the caller needs to deinit the string returned
-    pub fn toString(self: Value, allocator: Allocator) ![]const u8 {
-        return self.context.valueToString(self.value, .{ .allocator = allocator });
-    }
-
-    pub fn fromJson(ctx: *Context, json: []const u8) !Value {
-        const json_string = v8.String.initUtf8(ctx.isolate, json);
-        const value = try v8.Json.parse(ctx.v8_context, json_string);
-        return Value{ .context = ctx, .value = value };
-    }
-};
-
-pub const ValueIterator = struct {
-    count: u32,
-    idx: u32 = 0,
-    js_obj: v8.Object,
-    context: *const Context,
-
-    pub fn next(self: *ValueIterator) !?Value {
-        const idx = self.idx;
-        if (idx == self.count) {
-            return null;
-        }
-        self.idx += 1;
-
-        const context = self.context;
-        const js_val = try self.js_obj.getAtIndex(context.v8_context, idx);
-        return context.createValue(js_val);
-    }
-};
-
-pub fn UndefinedOr(comptime T: type) type {
-    return union(enum) {
-        undefined: void,
-        value: T,
-    };
-}
-
-// An interface for types that want to have their jsScopeEnd function be
-// called when the call context ends
-const CallScopeEndCallback = struct {
-    ptr: *anyopaque,
-    callScopeEndFn: *const fn (ptr: *anyopaque) void,
-
-    fn init(ptr: anytype) CallScopeEndCallback {
-        const T = @TypeOf(ptr);
-        const ptr_info = @typeInfo(T);
-
-        const gen = struct {
-            pub fn callScopeEnd(pointer: *anyopaque) void {
-                const self: T = @ptrCast(@alignCast(pointer));
-                return ptr_info.pointer.child.jsCallScopeEnd(self);
-            }
-        };
-
-        return .{
-            .ptr = ptr,
-            .callScopeEndFn = gen.callScopeEnd,
-        };
-    }
-
-    pub fn callScopeEnd(self: CallScopeEndCallback) void {
-        self.callScopeEndFn(self.ptr);
-    }
-};
-
-// Callback called on global's property missing.
-// Return true to intercept the execution or false to let the call
-// continue the chain.
-pub const GlobalMissingCallback = struct {
-    ptr: *anyopaque,
-    missingFn: *const fn (ptr: *anyopaque, name: []const u8, ctx: *Context) bool,
-
-    pub fn init(ptr: anytype) GlobalMissingCallback {
-        const T = @TypeOf(ptr);
-        const ptr_info = @typeInfo(T);
-
-        const gen = struct {
-            pub fn missing(pointer: *anyopaque, name: []const u8, ctx: *Context) bool {
-                const self: T = @ptrCast(@alignCast(pointer));
-                return ptr_info.pointer.child.missing(self, name, ctx);
-            }
-        };
-
-        return .{
-            .ptr = ptr,
-            .missingFn = gen.missing,
-        };
-    }
-
-    pub fn missing(self: GlobalMissingCallback, name: []const u8, ctx: *Context) bool {
-        return self.missingFn(self.ptr, name, ctx);
-    }
-};
-
-// Attributes that return a primitive type are setup directly on the
-// FunctionTemplate when the Env is setup. More complex types need a v8.Context
-// and cannot be set directly on the FunctionTemplate.
-// We default to saying types are primitives because that's mostly what
-// we have. If we add a new complex type that isn't explictly handled here,
-// we'll get a compiler error in simpleZigValueToJs, and can then explicitly
-// add the type here.
-pub fn isComplexAttributeType(ti: std.builtin.Type) bool {
-    return switch (ti) {
-        .array => true,
-        else => false,
-    };
-}
-
-// These are simple types that we can convert to JS with only an isolate. This
-// is separated from the Caller's zigValueToJs to make it available when we
-// don't have a caller (i.e., when setting static attributes on types)
-pub fn simpleZigValueToJs(isolate: v8.Isolate, value: anytype, comptime fail: bool) if (fail) v8.Value else ?v8.Value {
-    switch (@typeInfo(@TypeOf(value))) {
-        .void => return v8.initUndefined(isolate).toValue(),
-        .null => return v8.initNull(isolate).toValue(),
-        .bool => return v8.getValue(if (value) v8.initTrue(isolate) else v8.initFalse(isolate)),
-        .int => |n| switch (n.signedness) {
-            .signed => {
-                if (value >= -2_147_483_648 and value <= 2_147_483_647) {
-                    return v8.Integer.initI32(isolate, @intCast(value)).toValue();
-                }
-                if (comptime n.bits <= 64) {
-                    return v8.getValue(v8.BigInt.initI64(isolate, @intCast(value)));
-                }
-                @compileError(@typeName(value) ++ " is not supported");
-            },
-            .unsigned => {
-                if (value <= 4_294_967_295) {
-                    return v8.Integer.initU32(isolate, @intCast(value)).toValue();
-                }
-                if (comptime n.bits <= 64) {
-                    return v8.getValue(v8.BigInt.initU64(isolate, @intCast(value)));
-                }
-                @compileError(@typeName(value) ++ " is not supported");
-            },
-        },
-        .comptime_int => {
-            if (value >= 0) {
-                if (value <= 4_294_967_295) {
-                    return v8.Integer.initU32(isolate, @intCast(value)).toValue();
-                }
-                return v8.BigInt.initU64(isolate, @intCast(value)).toValue();
-            }
-            if (value >= -2_147_483_648) {
-                return v8.Integer.initI32(isolate, @intCast(value)).toValue();
-            }
-            return v8.BigInt.initI64(isolate, @intCast(value)).toValue();
-        },
-        .comptime_float => return v8.Number.init(isolate, value).toValue(),
-        .float => |f| switch (f.bits) {
-            64 => return v8.Number.init(isolate, value).toValue(),
-            32 => return v8.Number.init(isolate, @floatCast(value)).toValue(),
-            else => @compileError(@typeName(value) ++ " is not supported"),
-        },
-        .pointer => |ptr| {
-            if (ptr.size == .slice and ptr.child == u8) {
-                return v8.String.initUtf8(isolate, value).toValue();
-            }
-            if (ptr.size == .one) {
-                const one_info = @typeInfo(ptr.child);
-                if (one_info == .array and one_info.array.child == u8) {
-                    return v8.String.initUtf8(isolate, value).toValue();
-                }
-            }
-        },
-        .array => return simpleZigValueToJs(isolate, &value, fail),
-        .optional => {
-            if (value) |v| {
-                return simpleZigValueToJs(isolate, v, fail);
-            }
-            return v8.initNull(isolate).toValue();
-        },
-        .@"struct" => {
-            const T = @TypeOf(value);
-            if (@hasDecl(T, "_TYPED_ARRAY_ID_KLUDGE")) {
-                const values = value.values;
-                const value_type = @typeInfo(@TypeOf(values)).pointer.child;
-                const len = values.len;
-                const bits = switch (@typeInfo(value_type)) {
-                    .int => |n| n.bits,
-                    .float => |f| f.bits,
-                    else => @compileError("Invalid TypeArray type: " ++ @typeName(value_type)),
-                };
-
-                var array_buffer: v8.ArrayBuffer = undefined;
-                if (len == 0) {
-                    array_buffer = v8.ArrayBuffer.init(isolate, 0);
-                } else {
-                    const buffer_len = len * bits / 8;
-                    const backing_store = v8.BackingStore.init(isolate, buffer_len);
-                    const data: [*]u8 = @ptrCast(@alignCast(backing_store.getData()));
-                    @memcpy(data[0..buffer_len], @as([]const u8, @ptrCast(values))[0..buffer_len]);
-                    array_buffer = v8.ArrayBuffer.initWithBackingStore(isolate, &backing_store.toSharedPtr());
-                }
-
-                switch (@typeInfo(value_type)) {
-                    .int => |n| switch (n.signedness) {
-                        .unsigned => switch (n.bits) {
-                            8 => return v8.Uint8Array.init(array_buffer, 0, len).toValue(),
-                            16 => return v8.Uint16Array.init(array_buffer, 0, len).toValue(),
-                            32 => return v8.Uint32Array.init(array_buffer, 0, len).toValue(),
-                            64 => return v8.BigUint64Array.init(array_buffer, 0, len).toValue(),
-                            else => {},
-                        },
-                        .signed => switch (n.bits) {
-                            8 => return v8.Int8Array.init(array_buffer, 0, len).toValue(),
-                            16 => return v8.Int16Array.init(array_buffer, 0, len).toValue(),
-                            32 => return v8.Int32Array.init(array_buffer, 0, len).toValue(),
-                            64 => return v8.BigInt64Array.init(array_buffer, 0, len).toValue(),
-                            else => {},
-                        },
-                    },
-                    .float => |f| switch (f.bits) {
-                        32 => return v8.Float32Array.init(array_buffer, 0, len).toValue(),
-                        64 => return v8.Float64Array.init(array_buffer, 0, len).toValue(),
-                        else => {},
-                    },
-                    else => {},
-                }
-                // We normally don't fail in this function unless fail == true
-                // but this can never be valid.
-                @compileError("Invalid TypeArray type: " ++ @typeName(value_type));
-            }
-        },
-        .@"union" => return simpleZigValueToJs(isolate, std.meta.activeTag(value), fail),
-        .@"enum" => {
-            const T = @TypeOf(value);
-            if (@hasDecl(T, "toString")) {
-                // This should be deprecated in favor of the ENUM_JS_USE_TAG.
-                return simpleZigValueToJs(isolate, value.toString(), fail);
-            }
-
-            if (@hasDecl(T, "ENUM_JS_USE_TAG")) {
-                return simpleZigValueToJs(isolate, @tagName(value), fail);
-            }
-        },
-        else => {},
-    }
-    if (fail) {
-        @compileError("Unsupported Zig type " ++ @typeName(@TypeOf(value)));
-    }
-    return null;
-}
-
-pub fn _createException(isolate: v8.Isolate, msg: []const u8) v8.Value {
-    return v8.Exception.initError(v8.String.initUtf8(isolate, msg));
-}
-
-pub fn classNameForStruct(comptime Struct: type) []const u8 {
-    if (@hasDecl(Struct, "js_name")) {
-        return Struct.js_name;
-    }
-    @setEvalBranchQuota(10_000);
-    const full_name = @typeName(Struct);
-    const last = std.mem.lastIndexOfScalar(u8, full_name, '.') orelse return full_name;
-    return full_name[last + 1 ..];
-}
-
-// When we return a Zig object to V8, we put it on the heap and pass it into
-// v8 as an *anyopaque (i.e. void *). When V8 gives us back the value, say, as a
-// function parameter, we know what type it _should_ be. Above, in Caller.method
-// (for example), we know all the parameter types. So if a Zig function takes
-// a single parameter (its receiver), we know what that type is.
-//
-// In a simple/perfect world, we could use this knowledge to cast the *anyopaque
-// to the parameter type:
-//   const arg: @typeInfo(@TypeOf(function)).@"fn".params[0] = @ptrCast(v8_data);
-//
-// But there are 2 reasons we can't do that.
-//
-// == Reason 1 ==
-// The JS code might pass the wrong type:
-//
-//   var cat = new Cat();
-//   cat.setOwner(new Cat());
-//
-// The zig _setOwner method expects the 2nd parameter to be an *Owner, but
-// the JS code passed a *Cat.
-//
-// To solve this issue, we tag every returned value so that we can check what
-// type it is. In the above case, we'd expect an *Owner, but the tag would tell
-// us that we got a *Cat. We use the type index in our Types lookup as the tag.
-//
-// == Reason 2 ==
-// Because of prototype inheritance, even "correct" code can be a challenge. For
-// example, say the above JavaScript is fixed:
-//
-//   var cat = new Cat();
-//   cat.setOwner(new Owner("Leto"));
-//
-// The issue is that setOwner might not expect an *Owner, but rather a
-// *Person, which is the prototype for Owner. Now our Zig code is expecting
-// a *Person, but it was (correctly) given an *Owner.
-// For this reason, we also store the prototype's type index.
-//
-// One of the prototype mechanisms that we support is via composition. Owner
-// can have a "proto: *Person" field. For this reason, we also store the offset
-// of the proto field, so that, given an intFromPtr(*Owner) we can access its
-// proto field.
-//
-// The other prototype mechanism that we support is for netsurf, where we just
-// cast one type to another. In this case, we'll store an offset of -1 (as a
-// sentinel to indicate that we should just cast directly).
-pub const TaggedAnyOpaque = struct {
-    // The type of object this is. The type is captured as an index, which
-    // corresponds to both a field in TYPE_LOOKUP and the index of
-    // PROTOTYPE_TABLE
-    index: u16,
-
-    // Ptr to the Zig instance. Between the context where it's called (i.e.
-    // we have the comptime parameter info for all functions), and the index field
-    // we can figure out what type this is.
-    ptr: *anyopaque,
-
-    // When we're asked to describe an object via the Inspector, we _must_ include
-    // the proper subtype (and description) fields in the returned JSON.
-    // V8 will give us a Value and ask us for the subtype. From the v8.Value we
-    // can get a v8.Object, and from the v8.Object, we can get out TaggedAnyOpaque
-    // which is where we store the subtype.
-    subtype: ?types.Sub,
-};
-
-// These are here, and not in Inspector.zig, because Inspector.zig isn't always
-// included (e.g. in the wpt build).
-
-// This is called from V8. Whenever the v8 inspector has to describe a value
-// it'll call this function to gets its [optional] subtype - which, from V8's
-// point of view, is an arbitrary string.
-pub export fn v8_inspector__Client__IMPL__valueSubtype(
-    _: *v8.c.InspectorClientImpl,
-    c_value: *const v8.C_Value,
-) callconv(.c) [*c]const u8 {
-    const external_entry = Inspector.getTaggedAnyOpaque(.{ .handle = c_value }) orelse return null;
-    return if (external_entry.subtype) |st| @tagName(st) else null;
-}
-
-// Same as valueSubType above, but for the optional description field.
-// From what I can tell, some drivers _need_ the description field to be
-// present, even if it's empty. So if we have a subType for the value, we'll
-// put an empty description.
-pub export fn v8_inspector__Client__IMPL__descriptionForValueSubtype(
-    _: *v8.c.InspectorClientImpl,
-    v8_context: *const v8.C_Context,
-    c_value: *const v8.C_Value,
-) callconv(.c) [*c]const u8 {
-    _ = v8_context;
-
-    // We _must_ include a non-null description in order for the subtype value
-    // to be included. Besides that, I don't know if the value has any meaning
-    const external_entry = Inspector.getTaggedAnyOpaque(.{ .handle = c_value }) orelse return null;
-    return if (external_entry.subtype == null) null else "";
-}

src/browser/js/types.zig

@@ -1,184 +0,0 @@
-const std = @import("std");
-
-const generate = @import("generate.zig");
-
-const Interfaces = generate.Tuple(.{
-    @import("../crypto/crypto.zig").Crypto,
-    @import("../console/console.zig").Console,
-    @import("../css/css.zig").Interfaces,
-    @import("../cssom/cssom.zig").Interfaces,
-    @import("../dom/dom.zig").Interfaces,
-    @import("../dom/shadow_root.zig").ShadowRoot,
-    @import("../encoding/encoding.zig").Interfaces,
-    @import("../events/event.zig").Interfaces,
-    @import("../html/html.zig").Interfaces,
-    @import("../iterator/iterator.zig").Interfaces,
-    @import("../storage/storage.zig").Interfaces,
-    @import("../url/url.zig").Interfaces,
-    @import("../xhr/xhr.zig").Interfaces,
-    @import("../navigation/navigation.zig").Interfaces,
-    @import("../xhr/form_data.zig").Interfaces,
-    @import("../xhr/File.zig"),
-    @import("../xmlserializer/xmlserializer.zig").Interfaces,
-    @import("../fetch/fetch.zig").Interfaces,
-    @import("../streams/streams.zig").Interfaces,
-});
-
-pub const Types = @typeInfo(Interfaces).@"struct".fields;
-
-// Imagine we have a type Cat which has a getter:
-//
-//    fn get_owner(self: *Cat) *Owner {
-//        return self.owner;
-//    }
-//
-// When we execute caller.getter, we'll end up doing something like:
-//   const res = @call(.auto, Cat.get_owner, .{cat_instance});
-//
-// How do we turn `res`, which is an *Owner, into something we can return
-// to v8? We need the ObjectTemplate associated with Owner. How do we
-// get that? Well, we store all the ObjectTemplates in an array that's
-// tied to env. So we do something like:
-//
-//    env.templates[index_of_owner].initInstance(...);
-//
-// But how do we get that `index_of_owner`? `Lookup` is a struct
-// that looks like:
-//
-// const Lookup = struct {
-//     comptime cat: usize = 0,
-//     comptime owner: usize = 1,
-//     ...
-// }
-//
-// So to get the template index of `owner`, we can do:
-//
-//  const index_id = @field(type_lookup, @typeName(@TypeOf(res));
-//
-pub const Lookup = blk: {
-    var fields: [Types.len]std.builtin.Type.StructField = undefined;
-    for (Types, 0..) |s, i| {
-
-        // This prototype type check has nothing to do with building our
-        // Lookup. But we put it here, early, so that the rest of the
-        // code doesn't have to worry about checking if Struct.prototype is
-        // a pointer.
-        const Struct = s.defaultValue().?;
-        if (@hasDecl(Struct, "prototype") and @typeInfo(Struct.prototype) != .pointer) {
-            @compileError(std.fmt.comptimePrint("Prototype '{s}' for type '{s} must be a pointer", .{ @typeName(Struct.prototype), @typeName(Struct) }));
-        }
-
-        fields[i] = .{
-            .name = @typeName(Receiver(Struct)),
-            .type = usize,
-            .is_comptime = true,
-            .alignment = @alignOf(usize),
-            .default_value_ptr = &i,
-        };
-    }
-    break :blk @Type(.{ .@"struct" = .{
-        .layout = .auto,
-        .decls = &.{},
-        .is_tuple = false,
-        .fields = &fields,
-    } });
-};
-
-pub const LOOKUP = Lookup{};
-
-// Creates a list where the index of a type contains its prototype index
-//   const Animal = struct{};
-//   const Cat = struct{
-//       pub const prototype = *Animal;
-// };
-//
-// Would create an array: [0, 0]
-// Animal, at index, 0, has no prototype, so we set it to itself
-// Cat, at index 1, has an Animal prototype, so we set it to 0.
-//
-// When we're trying to pass an argument to a Zig function, we'll know the
-// target type (the function parameter type), and we'll have a
-// TaggedAnyOpaque which will have the index of the type of that parameter.
-// We'll use the PROTOTYPE_TABLE to see if the TaggedAnyType should be
-// cast to a prototype.
-pub const PROTOTYPE_TABLE = blk: {
-    var table: [Types.len]u16 = undefined;
-    for (Types, 0..) |s, i| {
-        var prototype_index = i;
-        const Struct = s.defaultValue().?;
-        if (@hasDecl(Struct, "prototype")) {
-            const TI = @typeInfo(Struct.prototype);
-            const proto_name = @typeName(Receiver(TI.pointer.child));
-            prototype_index = @field(LOOKUP, proto_name);
-        }
-        table[i] = prototype_index;
-    }
-    break :blk table;
-};
-
-// This is essentially meta data for each type. Each is stored in env.meta_lookup
-// The index for a type can be retrieved via:
-//   const index = @field(TYPE_LOOKUP, @typeName(Receiver(Struct)));
-//   const meta = env.meta_lookup[index];
-pub const Meta = struct {
-    // Every type is given a unique index. That index is used to lookup various
-    // things, i.e. the prototype chain.
-    index: u16,
-
-    // We store the type's subtype here, so that when we create an instance of
-    // the type, and bind it to JavaScript, we can store the subtype along with
-    // the created TaggedAnyOpaque.s
-    subtype: ?Sub,
-
-    // If this type has composition-based prototype, represents the byte-offset
-    // from ptr where the `proto` field is located. A negative offsets is used
-    // to indicate that the prototype field is behind a pointer.
-    proto_offset: i32,
-};
-
-pub const Sub = enum {
-    @"error",
-    array,
-    arraybuffer,
-    dataview,
-    date,
-    generator,
-    iterator,
-    map,
-    node,
-    promise,
-    proxy,
-    regexp,
-    set,
-    typedarray,
-    wasmvalue,
-    weakmap,
-    weakset,
-    webassemblymemory,
-};
-
-// When we map a Zig instance into a JsObject, we'll normally store the a
-// TaggedAnyOpaque (TAO) inside of the JsObject's internal field. This requires
-// ensuring that the instance template has an InternalFieldCount of 1. However,
-// for empty objects, we don't need to store the TAO, because we can't just cast
-// one empty object to another, so for those, as an optimization, we do not set
-// the InternalFieldCount.
-pub fn isEmpty(comptime T: type) bool {
-    return @typeInfo(T) != .@"opaque" and @sizeOf(T) == 0 and @hasDecl(T, "js_legacy_factory") == false;
-}
-
-// If we have a struct:
-// const Cat = struct {
-//    pub fn meow(self: *Cat) void { ... }
-// }
-// Then obviously, the receiver of its methods are going to be a *Cat (or *const Cat)
-//
-// However, we can also do:
-// const Cat = struct {
-//    pub const Self = OtherImpl;
-//    pub fn meow(self: *OtherImpl) void { ... }
-// }
-// In which case, as we see above, the receiver is derived from the Self declaration
-pub fn Receiver(comptime Struct: type) type {
-    return if (@hasDecl(Struct, "Self")) Struct.Self else Struct;
-}

src/browser/mimalloc.zig

@@ -26,9 +26,14 @@ const c = @cImport({
     @cInclude("mimalloc.h");
 });
 
+const Error = error{
+    HeapNotNull,
+    HeapNull,
+};
+
 var heap: ?*c.mi_heap_t = null;
 
-pub fn create() void {
+pub fn create() Error!void {
     std.debug.assert(heap == null);
     heap = c.mi_heap_new();
     std.debug.assert(heap != null);
@@ -40,45 +45,6 @@ pub fn destroy() void {
     heap = null;
 }
 
-pub fn getRSS() i64 {
-    if (@import("builtin").mode != .Debug) {
-        // just don't trust my implementation, plus a caller might not know
-        // that this requires parsing some unstructured data
-        @compileError("Only available in debug builds");
-    }
-    var buf: [1024 * 8]u8 = undefined;
-    var fba = std.heap.FixedBufferAllocator.init(&buf);
-    var writer = std.Io.Writer.Allocating.init(fba.allocator());
-
-    c.mi_stats_print_out(struct {
-        fn print(msg: [*c]const u8, data: ?*anyopaque) callconv(.c) void {
-            const w: *std.Io.Writer = @ptrCast(@alignCast(data.?));
-            w.writeAll(std.mem.span(msg)) catch |err| {
-                std.debug.print("Failed to write mimalloc data: {}\n", .{err});
-            };
-        }
-    }.print, &writer.writer);
-
-    const data = writer.written();
-    const index = std.mem.indexOf(u8, data, "rss: ") orelse return -1;
-    const sep = std.mem.indexOfScalarPos(u8, data, index + 5, ' ') orelse return -2;
-    const value = std.fmt.parseFloat(f64, data[index + 5 .. sep]) catch return -3;
-    const unit = data[sep + 1 ..];
-    if (std.mem.startsWith(u8, unit, "KiB,")) {
-        return @as(i64, @intFromFloat(value)) * 1024;
-    }
-
-    if (std.mem.startsWith(u8, unit, "MiB,")) {
-        return @as(i64, @intFromFloat(value)) * 1024 * 1024;
-    }
-
-    if (std.mem.startsWith(u8, unit, "GiB,")) {
-        return @as(i64, @intFromFloat(value)) * 1024 * 1024 * 1024;
-    }
-
-    return -4;
-}
-
 pub export fn m_alloc(size: usize) callconv(.c) ?*anyopaque {
     std.debug.assert(heap != null);
     return c.mi_heap_malloc(heap.?, size);

src/browser/mime.zig

@@ -17,6 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const Allocator = std.mem.Allocator;
 
 pub const Mime = struct {
     content_type: ContentType,
@@ -54,7 +55,7 @@ pub const Mime = struct {
     };
 
     /// Returns the null-terminated charset value.
-    pub fn charsetString(mime: *const Mime) [:0]const u8 {
+    pub inline fn charsetString(mime: *const Mime) [:0]const u8 {
         return @ptrCast(&mime.charset);
     }
 

src/browser/navigation/Navigation.zig

@@ -1,292 +0,0 @@
-// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-const log = @import("../../log.zig");
-const URL = @import("../../url.zig").URL;
-
-const js = @import("../js/js.zig");
-const Page = @import("../page.zig").Page;
-
-const DirectEventHandler = @import("../events/event.zig").DirectEventHandler;
-const EventTarget = @import("../dom/event_target.zig").EventTarget;
-const EventHandler = @import("../events/event.zig").EventHandler;
-
-const parser = @import("../netsurf.zig");
-
-// https://developer.mozilla.org/en-US/docs/Web/API/Navigation
-const Navigation = @This();
-
-const NavigationKind = @import("navigation.zig").NavigationKind;
-const NavigationHistoryEntry = @import("navigation.zig").NavigationHistoryEntry;
-const NavigationTransition = @import("navigation.zig").NavigationTransition;
-const NavigationEventTarget = @import("NavigationEventTarget.zig");
-
-const NavigationCurrentEntryChangeEvent = @import("navigation.zig").NavigationCurrentEntryChangeEvent;
-
-pub const prototype = *NavigationEventTarget;
-proto: NavigationEventTarget = NavigationEventTarget{},
-
-index: usize = 0,
-// Need to be stable pointers, because Events can reference entries.
-entries: std.ArrayListUnmanaged(*NavigationHistoryEntry) = .empty,
-next_entry_id: usize = 0,
-
-pub fn get_canGoBack(self: *const Navigation) bool {
-    return self.index > 0;
-}
-
-pub fn get_canGoForward(self: *const Navigation) bool {
-    return self.entries.items.len > self.index + 1;
-}
-
-pub fn currentEntry(self: *Navigation) *NavigationHistoryEntry {
-    return self.entries.items[self.index];
-}
-
-pub fn get_currentEntry(self: *Navigation) *NavigationHistoryEntry {
-    return self.currentEntry();
-}
-
-pub fn get_transition(_: *const Navigation) ?NavigationTransition {
-    // For now, all transitions are just considered complete.
-    return null;
-}
-
-const NavigationReturn = struct {
-    committed: js.Promise,
-    finished: js.Promise,
-};
-
-pub fn _back(self: *Navigation, page: *Page) !NavigationReturn {
-    if (!self.get_canGoBack()) {
-        return error.InvalidStateError;
-    }
-
-    const new_index = self.index - 1;
-    const next_entry = self.entries.items[new_index];
-    self.index = new_index;
-
-    return self.navigate(next_entry.url, .{ .traverse = new_index }, page);
-}
-
-pub fn _entries(self: *const Navigation) []*NavigationHistoryEntry {
-    return self.entries.items;
-}
-
-pub fn _forward(self: *Navigation, page: *Page) !NavigationReturn {
-    if (!self.get_canGoForward()) {
-        return error.InvalidStateError;
-    }
-
-    const new_index = self.index + 1;
-    const next_entry = self.entries.items[new_index];
-    self.index = new_index;
-
-    return self.navigate(next_entry.url, .{ .traverse = new_index }, page);
-}
-
-// This is for after true navigation processing, where we need to ensure that our entries are up to date.
-// This is only really safe to run in the `pageDoneCallback` where we can guarantee that the URL and NavigationKind are correct.
-pub fn processNavigation(self: *Navigation, page: *Page) !void {
-    const url = page.url.raw;
-    const kind = page.session.navigation_kind;
-
-    if (kind) |k| {
-        switch (k) {
-            .replace => {
-                // When replacing, we just update the URL but the state is nullified.
-                const entry = self.currentEntry();
-                entry.url = url;
-                entry.state = null;
-            },
-            .push => |state| {
-                _ = try self.pushEntry(url, state, page, false);
-            },
-            .traverse, .reload => {},
-        }
-    } else {
-        _ = try self.pushEntry(url, null, page, false);
-    }
-}
-
-/// Pushes an entry into the Navigation stack WITHOUT actually navigating to it.
-/// For that, use `navigate`.
-pub fn pushEntry(self: *Navigation, _url: []const u8, state: ?[]const u8, page: *Page, dispatch: bool) !*NavigationHistoryEntry {
-    const arena = page.session.arena;
-
-    const url = try arena.dupe(u8, _url);
-
-    // truncates our history here.
-    if (self.entries.items.len > self.index + 1) {
-        self.entries.shrinkRetainingCapacity(self.index + 1);
-    }
-
-    const index = self.entries.items.len;
-
-    const id = self.next_entry_id;
-    self.next_entry_id += 1;
-
-    const id_str = try std.fmt.allocPrint(arena, "{d}", .{id});
-
-    const entry = try arena.create(NavigationHistoryEntry);
-    entry.* = NavigationHistoryEntry{
-        .id = id_str,
-        .key = id_str,
-        .url = url,
-        .state = state,
-    };
-
-    // we don't always have a current entry...
-    const previous = if (self.entries.items.len > 0) self.currentEntry() else null;
-    try self.entries.append(arena, entry);
-    if (previous) |prev| {
-        if (dispatch) {
-            NavigationCurrentEntryChangeEvent.dispatch(self, prev, .push);
-        }
-    }
-
-    self.index = index;
-
-    return entry;
-}
-
-const NavigateOptions = struct {
-    const NavigateOptionsHistory = enum {
-        pub const ENUM_JS_USE_TAG = true;
-
-        auto,
-        push,
-        replace,
-    };
-
-    state: ?js.Object = null,
-    info: ?js.Object = null,
-    history: NavigateOptionsHistory = .auto,
-};
-
-pub fn navigate(
-    self: *Navigation,
-    _url: ?[]const u8,
-    kind: NavigationKind,
-    page: *Page,
-) !NavigationReturn {
-    const arena = page.session.arena;
-    const url = _url orelse return error.MissingURL;
-
-    // https://github.com/WICG/navigation-api/issues/95
-    //
-    // These will only settle on same-origin navigation (mostly intended for SPAs).
-    // It is fine (and expected) for these to not settle on cross-origin requests :)
-    const committed = try page.js.createPromiseResolver(.page);
-    const finished = try page.js.createPromiseResolver(.page);
-
-    const new_url = try URL.parse(url, null);
-    const is_same_document = try page.url.eqlDocument(&new_url, arena);
-
-    switch (kind) {
-        .push => |state| {
-            if (is_same_document) {
-                page.url = new_url;
-
-                try committed.resolve({});
-                // todo: Fire navigate event
-                try finished.resolve({});
-
-                _ = try self.pushEntry(url, state, page, true);
-            } else {
-                try page.navigateFromWebAPI(url, .{ .reason = .navigation }, kind);
-            }
-        },
-        .traverse => |index| {
-            self.index = index;
-
-            if (is_same_document) {
-                page.url = new_url;
-
-                try committed.resolve({});
-                // todo: Fire navigate event
-                try finished.resolve({});
-            } else {
-                try page.navigateFromWebAPI(url, .{ .reason = .navigation }, kind);
-            }
-        },
-        .reload => {
-            try page.navigateFromWebAPI(url, .{ .reason = .navigation }, kind);
-        },
-        else => unreachable,
-    }
-
-    return .{
-        .committed = committed.promise(),
-        .finished = finished.promise(),
-    };
-}
-
-pub fn _navigate(self: *Navigation, _url: []const u8, _opts: ?NavigateOptions, page: *Page) !NavigationReturn {
-    const opts = _opts orelse NavigateOptions{};
-    const json = if (opts.state) |state| state.toJson(page.session.arena) catch return error.DataClone else null;
-    return try self.navigate(_url, .{ .push = json }, page);
-}
-
-pub const ReloadOptions = struct {
-    state: ?js.Object = null,
-    info: ?js.Object = null,
-};
-
-pub fn _reload(self: *Navigation, _opts: ?ReloadOptions, page: *Page) !NavigationReturn {
-    const arena = page.session.arena;
-
-    const opts = _opts orelse ReloadOptions{};
-    const entry = self.currentEntry();
-    if (opts.state) |state| {
-        const previous = entry;
-        entry.state = state.toJson(arena) catch return error.DataClone;
-        NavigationCurrentEntryChangeEvent.dispatch(self, previous, .reload);
-    }
-
-    return self.navigate(entry.url, .reload, page);
-}
-
-pub const TraverseToOptions = struct {
-    info: ?js.Object = null,
-};
-
-pub fn _traverseTo(self: *Navigation, key: []const u8, _opts: ?TraverseToOptions, page: *Page) !NavigationReturn {
-    log.debug(.browser, "not implemented", .{ .options = _opts });
-
-    for (self.entries.items, 0..) |entry, i| {
-        if (std.mem.eql(u8, key, entry.key)) {
-            return try self.navigate(entry.url, .{ .traverse = i }, page);
-        }
-    }
-
-    return error.InvalidStateError;
-}
-
-pub const UpdateCurrentEntryOptions = struct {
-    state: js.Object,
-};
-
-pub fn _updateCurrentEntry(self: *Navigation, options: UpdateCurrentEntryOptions, page: *Page) !void {
-    const arena = page.session.arena;
-
-    const previous = self.currentEntry();
-    self.currentEntry().state = options.state.toJson(arena) catch return error.DataClone;
-    NavigationCurrentEntryChangeEvent.dispatch(self, previous, null);
-}

src/browser/navigation/NavigationEventTarget.zig

@@ -1,56 +0,0 @@
-const std = @import("std");
-
-const js = @import("../js/js.zig");
-const Page = @import("../page.zig").Page;
-
-const EventTarget = @import("../dom/event_target.zig").EventTarget;
-const EventHandler = @import("../events/event.zig").EventHandler;
-
-const parser = @import("../netsurf.zig");
-
-pub const NavigationEventTarget = @This();
-
-pub const prototype = *EventTarget;
-// Extend libdom event target for pure zig struct.
-base: parser.EventTargetTBase = parser.EventTargetTBase{ .internal_target_type = .navigation },
-
-oncurrententrychange_cbk: ?js.Function = null,
-
-fn register(
-    self: *NavigationEventTarget,
-    alloc: std.mem.Allocator,
-    typ: []const u8,
-    listener: EventHandler.Listener,
-) !?js.Function {
-    const target = parser.toEventTarget(NavigationEventTarget, self);
-
-    // The only time this can return null if the listener is already
-    // registered. But before calling `register`, all of our functions
-    // remove any existing listener, so it should be impossible to get null
-    // from this function call.
-    const eh = (try EventHandler.register(alloc, target, typ, listener, null)) orelse unreachable;
-    return eh.callback;
-}
-
-fn unregister(self: *NavigationEventTarget, typ: []const u8, cbk_id: usize) !void {
-    const et = parser.toEventTarget(NavigationEventTarget, self);
-    // check if event target has already this listener
-    const lst = try parser.eventTargetHasListener(et, typ, false, cbk_id);
-    if (lst == null) {
-        return;
-    }
-
-    // remove listener
-    try parser.eventTargetRemoveEventListener(et, typ, lst.?, false);
-}
-
-pub fn get_oncurrententrychange(self: *NavigationEventTarget) ?js.Function {
-    return self.oncurrententrychange_cbk;
-}
-
-pub fn set_oncurrententrychange(self: *NavigationEventTarget, listener: ?EventHandler.Listener, page: *Page) !void {
-    if (self.oncurrententrychange_cbk) |cbk| try self.unregister("currententrychange", cbk.id);
-    if (listener) |listen| {
-        self.oncurrententrychange_cbk = try self.register(page.arena, "currententrychange", listen);
-    }
-}

src/browser/navigation/navigation.zig

@@ -1,215 +0,0 @@
-// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
-//
-// Francis Bouvier <francis@lightpanda.io>
-// Pierre Tachoire <pierre@lightpanda.io>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-const std = @import("std");
-const log = @import("../../log.zig");
-const URL = @import("../../url.zig").URL;
-
-const js = @import("../js/js.zig");
-const Page = @import("../page.zig").Page;
-
-const DirectEventHandler = @import("../events/event.zig").DirectEventHandler;
-const EventTarget = @import("../dom/event_target.zig").EventTarget;
-const EventHandler = @import("../events/event.zig").EventHandler;
-
-const parser = @import("../netsurf.zig");
-
-const Navigation = @import("Navigation.zig");
-const NavigationEventTarget = @import("NavigationEventTarget.zig");
-
-pub const Interfaces = .{
-    Navigation,
-    NavigationEventTarget,
-    NavigationActivation,
-    NavigationTransition,
-    NavigationHistoryEntry,
-};
-
-pub const NavigationType = enum {
-    pub const ENUM_JS_USE_TAG = true;
-
-    push,
-    replace,
-    traverse,
-    reload,
-};
-
-pub const NavigationKind = union(NavigationType) {
-    push: ?[]const u8,
-    replace,
-    traverse: usize,
-    reload,
-};
-
-// https://developer.mozilla.org/en-US/docs/Web/API/NavigationHistoryEntry
-pub const NavigationHistoryEntry = struct {
-    pub const prototype = *EventTarget;
-    base: parser.EventTargetTBase = parser.EventTargetTBase{ .internal_target_type = .plain },
-
-    id: []const u8,
-    key: []const u8,
-    url: ?[]const u8,
-    state: ?[]const u8,
-
-    pub fn get_id(self: *const NavigationHistoryEntry) []const u8 {
-        return self.id;
-    }
-
-    pub fn get_index(self: *const NavigationHistoryEntry, page: *Page) i32 {
-        const navigation = page.session.navigation;
-        for (navigation.entries.items, 0..) |entry, i| {
-            if (std.mem.eql(u8, entry.id, self.id)) {
-                return @intCast(i);
-            }
-        }
-
-        return -1;
-    }
-
-    pub fn get_key(self: *const NavigationHistoryEntry) []const u8 {
-        return self.key;
-    }
-
-    pub fn get_sameDocument(self: *const NavigationHistoryEntry, page: *Page) !bool {
-        const _url = self.url orelse return false;
-        const url = try URL.parse(_url, null);
-        return page.url.eqlDocument(&url, page.arena);
-    }
-
-    pub fn get_url(self: *const NavigationHistoryEntry) ?[]const u8 {
-        return self.url;
-    }
-
-    pub fn _getState(self: *const NavigationHistoryEntry, page: *Page) !?js.Value {
-        if (self.state) |state| {
-            return try js.Value.fromJson(page.js, state);
-        } else {
-            return null;
-        }
-    }
-};
-
-// https://developer.mozilla.org/en-US/docs/Web/API/NavigationActivation
-pub const NavigationActivation = struct {
-    const NavigationActivationType = enum {
-        pub const ENUM_JS_USE_TAG = true;
-
-        push,
-        reload,
-        replace,
-        traverse,
-    };
-
-    entry: NavigationHistoryEntry,
-    from: ?NavigationHistoryEntry = null,
-    type: NavigationActivationType,
-
-    pub fn get_entry(self: *const NavigationActivation) NavigationHistoryEntry {
-        return self.entry;
-    }
-
-    pub fn get_from(self: *const NavigationActivation) ?NavigationHistoryEntry {
-        return self.from;
-    }
-
-    pub fn get_navigationType(self: *const NavigationActivation) NavigationActivationType {
-        return self.type;
-    }
-};
-
-// https://developer.mozilla.org/en-US/docs/Web/API/NavigationTransition
-pub const NavigationTransition = struct {
-    finished: js.Promise,
-    from: NavigationHistoryEntry,
-    navigation_type: NavigationActivation.NavigationActivationType,
-};
-
-const Event = @import("../events/event.zig").Event;
-
-pub const NavigationCurrentEntryChangeEvent = struct {
-    pub const prototype = *Event;
-    pub const union_make_copy = true;
-
-    pub const EventInit = struct {
-        from: *NavigationHistoryEntry,
-        navigationType: ?NavigationType = null,
-    };
-
-    proto: parser.Event,
-    from: *NavigationHistoryEntry,
-    navigation_type: ?NavigationType,
-
-    pub fn constructor(event_type: []const u8, opts: EventInit) !NavigationCurrentEntryChangeEvent {
-        const event = try parser.eventCreate();
-        defer parser.eventDestroy(event);
-
-        try parser.eventInit(event, event_type, .{});
-        parser.eventSetInternalType(event, .navigation_current_entry_change_event);
-
-        return .{
-            .proto = event.*,
-            .from = opts.from,
-            .navigation_type = opts.navigationType,
-        };
-    }
-
-    pub fn get_from(self: *NavigationCurrentEntryChangeEvent) *NavigationHistoryEntry {
-        return self.from;
-    }
-
-    pub fn get_navigationType(self: *const NavigationCurrentEntryChangeEvent) ?NavigationType {
-        return self.navigation_type;
-    }
-
-    pub fn dispatch(navigation: *Navigation, from: *NavigationHistoryEntry, typ: ?NavigationType) void {
-        log.debug(.script_event, "dispatch event", .{
-            .type = "currententrychange",
-            .source = "navigation",
-        });
-
-        var evt = NavigationCurrentEntryChangeEvent.constructor(
-            "currententrychange",
-            .{ .from = from, .navigationType = typ },
-        ) catch |err| {
-            log.err(.app, "event constructor error", .{
-                .err = err,
-                .type = "currententrychange",
-                .source = "navigation",
-            });
-
-            return;
-        };
-
-        _ = parser.eventTargetDispatchEvent(
-            @as(*parser.EventTarget, @ptrCast(navigation)),
-            &evt.proto,
-        ) catch |err| {
-            log.err(.app, "dispatch event error", .{
-                .err = err,
-                .type = "currententrychange",
-                .source = "navigation",
-            });
-        };
-    }
-};
-
-const testing = @import("../../testing.zig");
-test "Browser: Navigation" {
-    try testing.htmlRunner("html/navigation/navigation.html");
-    try testing.htmlRunner("html/navigation/navigation_currententrychange.html");
-}

src/browser/netsurf.zig

@@ -36,8 +36,8 @@ const mimalloc = @import("mimalloc.zig");
 // init initializes netsurf lib.
 // init starts a mimalloc heap arena for the netsurf session. The caller must
 // call deinit() to free the arena memory.
-pub fn init() void {
-    mimalloc.create();
+pub fn init() !void {
+    try mimalloc.create();
 }
 
 // deinit frees the mimalloc heap arena memory.
@@ -84,7 +84,7 @@ pub fn deinit() void {
 // - VtableT: the type of the vtable (dom_node_vtable, dom_element_vtable, etc)
 // - NodeT: the type of the node interface (dom_element, dom_document, etc)
 // - node: the node interface instance
-fn getVtable(comptime VtableT: type, comptime NodeT: type, node: anytype) VtableT {
+inline fn getVtable(comptime VtableT: type, comptime NodeT: type, node: anytype) VtableT {
     // first align correctly the node interface
     const node_aligned: *align(@alignOf(NodeExternal)) NodeT = @alignCast(node);
     // then convert the node interface to a base node
@@ -101,12 +101,12 @@ fn getVtable(comptime VtableT: type, comptime NodeT: type, node: anytype) Vtable
 // Utils
 const String = c.dom_string;
 
-fn strToData(s: *String) []const u8 {
+inline fn strToData(s: *String) []const u8 {
     const data = c.dom_string_data(s);
     return data[0..c.dom_string_byte_length(s)];
 }
 
-pub fn strFromData(data: []const u8) !*String {
+pub inline fn strFromData(data: []const u8) !*String {
     var s: ?*String = null;
     const err = c.dom_string_create(data.ptr, data.len, &s);
     try DOMErr(err);
@@ -116,10 +116,10 @@ pub fn strFromData(data: []const u8) !*String {
 const LWCString = c.lwc_string;
 
 // TODO implement lwcStringToData
-// fn lwcStringToData(s: *LWCString) []const u8 {
+// inline fn lwcStringToData(s: *LWCString) []const u8 {
 // }
 
-fn lwcStringFromData(data: []const u8) !*LWCString {
+inline fn lwcStringFromData(data: []const u8) !*LWCString {
     var s: ?*LWCString = null;
     const err = c.lwc_intern_string(data.ptr, data.len, &s);
     try DOMErr(err);
@@ -445,15 +445,13 @@ pub fn eventInit(evt: *Event, typ: []const u8, opts: EventInit) !void {
     try DOMErr(err);
 }
 
-pub fn eventType(evt: *Event) []const u8 {
+pub fn eventType(evt: *Event) ![]const u8 {
     var s: ?*String = null;
     const err = c._dom_event_get_type(evt, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
 
     // if the event type is null, return a empty string.
-    if (s == null) {
-        return "";
-    }
+    if (s == null) return "";
 
     return strToData(s.?);
 }
@@ -558,9 +556,6 @@ pub const EventType = enum(u8) {
     xhr_event = 6,
     message_event = 7,
     keyboard_event = 8,
-    pop_state = 9,
-    composition_event = 10,
-    navigation_current_entry_change_event = 11,
 };
 
 pub const MutationEvent = c.dom_mutation_event;
@@ -576,18 +571,10 @@ pub fn mutationEventAttributeName(evt: *MutationEvent) ![]const u8 {
     return strToData(s.?);
 }
 
-pub fn mutationEventPrevValue(evt: *MutationEvent) ?[]const u8 {
+pub fn mutationEventPrevValue(evt: *MutationEvent) !?[]const u8 {
     var s: ?*String = null;
     const err = c._dom_mutation_event_get_prev_value(evt, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
-    if (s == null) return null;
-    return strToData(s.?);
-}
-
-pub fn mutationEventNewValue(evt: *MutationEvent) ?[]const u8 {
-    var s: ?*String = null;
-    const err = c._dom_mutation_event_get_new_value(evt, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) return null;
     return strToData(s.?);
 }
@@ -595,7 +582,7 @@ pub fn mutationEventNewValue(evt: *MutationEvent) ?[]const u8 {
 pub fn mutationEventRelatedNode(evt: *MutationEvent) !?*Node {
     var n: NodeExternal = undefined;
     const err = c._dom_mutation_event_get_related_node(evt, &n);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (n == null) return null;
     return @as(*Node, @ptrCast(@alignCast(n)));
 }
@@ -792,10 +779,10 @@ pub fn eventTargetDispatchEvent(et: *EventTarget, event: *Event) !bool {
     return res;
 }
 
-pub fn eventTargetInternalType(et: *EventTarget) EventTargetTBase.InternalType {
+pub fn eventTargetInternalType(et: *EventTarget) !EventTargetTBase.InternalType {
     var res: u32 = undefined;
     const err = eventTargetVtable(et).internal_type.?(et, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return @enumFromInt(res);
 }
 
@@ -832,7 +819,6 @@ pub const EventTargetTBase = extern struct {
         message_port = 7,
         screen = 8,
         screen_orientation = 9,
-        navigation = 10,
     };
 
     vtable: ?*const c.struct_dom_event_target_vtable = &c.struct_dom_event_target_vtable{
@@ -864,8 +850,10 @@ pub const EventTargetTBase = extern struct {
     pub fn dispatch_event(et: [*c]c.dom_event_target, evt: ?*c.struct_dom_event, res: [*c]bool) callconv(.c) c.dom_exception {
         const self = @as(*Self, @ptrCast(et));
         // Set the event target to the target dispatched.
-        const err = c._dom_event_set_target(evt, et);
-        std.debug.assert(err == c.DOM_NO_ERR);
+        const e = c._dom_event_set_target(evt, et);
+        if (e != c.DOM_NO_ERR) {
+            return e;
+        }
         return c._dom_event_target_dispatch(et, &self.eti, evt, c.DOM_AT_TARGET, res);
     }
 
@@ -1058,17 +1046,17 @@ pub const NodeType = enum(u4) {
 // NodeList
 pub const NodeList = c.dom_nodelist;
 
-pub fn nodeListLength(nodeList: *NodeList) u32 {
+pub fn nodeListLength(nodeList: *NodeList) !u32 {
     var ln: u32 = undefined;
     const err = c.dom_nodelist_get_length(nodeList, &ln);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return ln;
 }
 
-pub fn nodeListItem(nodeList: *NodeList, index: u32) ?*Node {
+pub fn nodeListItem(nodeList: *NodeList, index: u32) !?*Node {
     var n: NodeExternal = undefined;
     const err = c._dom_nodelist_item(nodeList, index, &n);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (n == null) return null;
     return @as(*Node, @ptrCast(@alignCast(n)));
 }
@@ -1185,86 +1173,88 @@ fn nodeVtable(node: *Node) c.dom_node_vtable {
 pub fn nodeLocalName(node: *Node) ![]const u8 {
     var s: ?*String = null;
     const err = nodeVtable(node).dom_node_get_local_name.?(node, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) return "";
-
     var s_lower: ?*String = null;
     const errStr = c.dom_string_tolower(s, true, &s_lower);
     try DOMErr(errStr);
     return strToData(s_lower.?);
 }
 
-pub fn nodeType(node: *Node) NodeType {
+pub fn nodeType(node: *Node) !NodeType {
     var node_type: c.dom_node_type = undefined;
     const err = nodeVtable(node).dom_node_get_node_type.?(node, &node_type);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return @as(NodeType, @enumFromInt(node_type));
 }
 
-pub fn nodeFirstChild(node: *Node) ?*Node {
+pub fn nodeFirstChild(node: *Node) !?*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_get_first_child.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeLastChild(node: *Node) ?*Node {
+pub fn nodeLastChild(node: *Node) !?*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_get_last_child.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeNextSibling(node: *Node) ?*Node {
+pub fn nodeNextSibling(node: *Node) !?*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_get_next_sibling.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeNextElementSibling(node: *Node) ?*Element {
+pub fn nodeNextElementSibling(node: *Node) !?*Element {
     var n = node;
     while (true) {
-        const res = nodeNextSibling(n) orelse return null;
+        const res = try nodeNextSibling(n);
+        if (res == null) return null;
 
-        if (nodeType(res) == .element) {
-            return @as(*Element, @ptrCast(res));
+        if (try nodeType(res.?) == .element) {
+            return @as(*Element, @ptrCast(res.?));
         }
-        n = res;
+        n = res.?;
     }
     return null;
 }
 
-pub fn nodePreviousSibling(node: *Node) ?*Node {
+pub fn nodePreviousSibling(node: *Node) !?*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_get_previous_sibling.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodePreviousElementSibling(node: *Node) ?*Element {
+pub fn nodePreviousElementSibling(node: *Node) !?*Element {
     var n = node;
     while (true) {
-        const res = nodePreviousSibling(n) orelse return null;
-        if (nodeType(res) == .element) {
-            return @as(*Element, @ptrCast(res));
+        const res = try nodePreviousSibling(n);
+        if (res == null) return null;
+
+        if (try nodeType(res.?) == .element) {
+            return @as(*Element, @ptrCast(res.?));
         }
-        n = res;
+        n = res.?;
     }
     return null;
 }
 
-pub fn nodeParentNode(node: *Node) ?*Node {
+pub fn nodeParentNode(node: *Node) !?*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_get_parent_node.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeParentElement(node: *Node) ?*Element {
-    const res = nodeParentNode(node);
+pub fn nodeParentElement(node: *Node) !?*Element {
+    const res = try nodeParentNode(node);
     if (res) |value| {
-        if (nodeType(value) == .element) {
+        if (try nodeType(value) == .element) {
             return @as(*Element, @ptrCast(value));
         }
     }
@@ -1279,17 +1269,17 @@ pub fn nodeName(node: *Node) ![]const u8 {
     return strToData(s.?);
 }
 
-pub fn nodeOwnerDocument(node: *Node) ?*Document {
+pub fn nodeOwnerDocument(node: *Node) !?*Document {
     var doc: ?*Document = null;
     const err = nodeVtable(node).dom_node_get_owner_document.?(node, &doc);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return doc;
 }
 
-pub fn nodeValue(node: *Node) ?[]const u8 {
+pub fn nodeValue(node: *Node) !?[]const u8 {
     var s: ?*String = null;
     const err = nodeVtable(node).dom_node_get_node_value.?(node, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) return null;
     return strToData(s.?);
 }
@@ -1300,14 +1290,14 @@ pub fn nodeSetValue(node: *Node, value: []const u8) !void {
     try DOMErr(err);
 }
 
-pub fn nodeTextContent(node: *Node) ?[]const u8 {
+pub fn nodeTextContent(node: *Node) !?[]const u8 {
     var s: ?*String = null;
     const err = nodeVtable(node).dom_node_get_text_content.?(node, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) {
         // NOTE: it seems that there is a bug in netsurf implem
         // an empty Element should return an empty string and not null
-        if (nodeType(node) == .element) {
+        if (try nodeType(node) == .element) {
             return "";
         }
         return null;
@@ -1328,10 +1318,10 @@ pub fn nodeGetChildNodes(node: *Node) !*NodeList {
     return nlist.?;
 }
 
-pub fn nodeGetRootNode(node: *Node) *Node {
+pub fn nodeGetRootNode(node: *Node) !*Node {
     var root = node;
     while (true) {
-        const parent = nodeParentNode(root);
+        const parent = try nodeParentNode(root);
         if (parent) |parent_| {
             root = parent_;
         } else break;
@@ -1353,21 +1343,21 @@ pub fn nodeCloneNode(node: *Node, is_deep: bool) !*Node {
     return res.?;
 }
 
-pub fn nodeContains(node: *Node, other: *Node) bool {
+pub fn nodeContains(node: *Node, other: *Node) !bool {
     var res: bool = undefined;
     const err = c._dom_node_contains(node, other, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeHasChildNodes(node: *Node) bool {
+pub fn nodeHasChildNodes(node: *Node) !bool {
     var res: bool = undefined;
     const err = nodeVtable(node).dom_node_has_child_nodes.?(node, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
-pub fn nodeInsertBefore(node: *Node, new_node: *Node, ref_node: ?*Node) !*Node {
+pub fn nodeInsertBefore(node: *Node, new_node: *Node, ref_node: *Node) !*Node {
     var res: ?*Node = null;
     const err = nodeVtable(node).dom_node_insert_before.?(node, new_node, ref_node, &res);
     try DOMErr(err);
@@ -1378,7 +1368,7 @@ pub fn nodeIsDefaultNamespace(node: *Node, namespace_: ?[]const u8) !bool {
     const s = if (namespace_) |n| try strFromData(n) else null;
     var res: bool = undefined;
     const err = nodeVtable(node).dom_node_is_default_namespace.?(node, s, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
@@ -1389,10 +1379,10 @@ pub fn nodeIsEqualNode(node: *Node, other: *Node) !bool {
     return res;
 }
 
-pub fn nodeIsSameNode(node: *Node, other: *Node) bool {
+pub fn nodeIsSameNode(node: *Node, other: *Node) !bool {
     var res: bool = undefined;
     const err = nodeVtable(node).dom_node_is_same.?(node, other, &res);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return res;
 }
 
@@ -1432,6 +1422,13 @@ pub fn nodeReplaceChild(node: *Node, new_child: *Node, old_child: *Node) !*Node
     return res.?;
 }
 
+pub fn nodeHasAttributes(node: *Node) !bool {
+    var res: bool = undefined;
+    const err = nodeVtable(node).dom_node_has_attributes.?(node, &res);
+    try DOMErr(err);
+    return res;
+}
+
 pub fn nodeGetAttributes(node: *Node) !?*NamedNodeMap {
     var res: ?*NamedNodeMap = null;
     const err = nodeVtable(node).dom_node_get_attributes.?(node, &res);
@@ -1439,18 +1436,18 @@ pub fn nodeGetAttributes(node: *Node) !?*NamedNodeMap {
     return res;
 }
 
-pub fn nodeGetNamespace(node: *Node) ?[]const u8 {
+pub fn nodeGetNamespace(node: *Node) !?[]const u8 {
     var s: ?*String = null;
     const err = nodeVtable(node).dom_node_get_namespace.?(node, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) return null;
     return strToData(s.?);
 }
 
-pub fn nodeGetPrefix(node: *Node) ?[]const u8 {
+pub fn nodeGetPrefix(node: *Node) !?[]const u8 {
     var s: ?*String = null;
     const err = nodeVtable(node).dom_node_get_prefix.?(node, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     if (s == null) return null;
     return strToData(s.?);
 }
@@ -1466,24 +1463,23 @@ pub fn nodeSetEmbedderData(node: *Node, data: *anyopaque) void {
 pub fn nodeGetElementById(node: *Node, id: []const u8) !?*Element {
     var el: ?*Element = null;
     const str_id = try strFromData(id);
-    const err = c._dom_find_element_by_id(node, str_id, &el);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(c._dom_find_element_by_id(node, str_id, &el));
     return el;
 }
 
 // nodeToElement is an helper to convert a node to an element.
-pub fn nodeToElement(node: *Node) *Element {
+pub inline fn nodeToElement(node: *Node) *Element {
     return @as(*Element, @ptrCast(node));
 }
 
 // nodeToDocument is an helper to convert a node to an document.
-pub fn nodeToDocument(node: *Node) *Document {
+pub inline fn nodeToDocument(node: *Node) *Document {
     return @as(*Document, @ptrCast(node));
 }
 
 // Combination of nodeToElement + elementTag
 pub fn nodeHTMLGetTagType(node: *Node) !?Tag {
-    if (nodeType(node) != .element) {
+    if (try nodeType(node) != .element) {
         return null;
     }
 
@@ -1497,14 +1493,14 @@ fn characterDataVtable(data: *CharacterData) c.dom_characterdata_vtable {
     return getVtable(c.dom_characterdata_vtable, CharacterData, data);
 }
 
-pub fn characterDataToNode(cdata: *CharacterData) *Node {
+pub inline fn characterDataToNode(cdata: *CharacterData) *Node {
     return @as(*Node, @ptrCast(@alignCast(cdata)));
 }
 
-pub fn characterDataData(cdata: *CharacterData) []const u8 {
+pub fn characterDataData(cdata: *CharacterData) ![]const u8 {
     var s: ?*String = null;
     const err = characterDataVtable(cdata).dom_characterdata_get_data.?(cdata, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return strToData(s.?);
 }
 
@@ -1517,7 +1513,7 @@ pub fn characterDataSetData(cdata: *CharacterData, data: []const u8) !void {
 pub fn characterDataLength(cdata: *CharacterData) !u32 {
     var n: u32 = undefined;
     const err = characterDataVtable(cdata).dom_characterdata_get_length.?(cdata, &n);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return n;
 }
 
@@ -1582,7 +1578,7 @@ pub const Comment = c.dom_comment;
 pub const ProcessingInstruction = c.dom_processing_instruction;
 
 // processingInstructionToNode is an helper to convert an ProcessingInstruction to a node.
-pub fn processingInstructionToNode(pi: *ProcessingInstruction) *Node {
+pub inline fn processingInstructionToNode(pi: *ProcessingInstruction) *Node {
     return @as(*Node, @ptrCast(@alignCast(pi)));
 }
 
@@ -1637,7 +1633,7 @@ pub fn attributeGetOwnerElement(a: *Attribute) !?*Element {
 }
 
 // attributeToNode is an helper to convert an attribute to a node.
-pub fn attributeToNode(a: *Attribute) *Node {
+pub inline fn attributeToNode(a: *Attribute) *Node {
     return @as(*Node, @ptrCast(@alignCast(a)));
 }
 
@@ -1799,7 +1795,7 @@ pub fn elementHasClass(elem: *Element, class: []const u8) !bool {
 }
 
 // elementToNode is an helper to convert an element to a node.
-pub fn elementToNode(e: *Element) *Node {
+pub inline fn elementToNode(e: *Element) *Node {
     return @as(*Node, @ptrCast(@alignCast(e)));
 }
 
@@ -1868,14 +1864,14 @@ fn elementHTMLVtable(elem_html: *ElementHTML) c.dom_html_element_vtable {
 // HTMLScriptElement
 
 // scriptToElt is an helper to convert an script to an element.
-pub fn scriptToElt(s: *Script) *Element {
+pub inline fn scriptToElt(s: *Script) *Element {
     return @as(*Element, @ptrCast(@alignCast(s)));
 }
 
 // HTMLAnchorElement
 
 // anchorToNode is an helper to convert an anchor to a node.
-pub fn anchorToNode(a: *Anchor) *Node {
+pub inline fn anchorToNode(a: *Anchor) *Node {
     return @as(*Node, @ptrCast(@alignCast(a)));
 }
 
@@ -1946,19 +1942,6 @@ pub fn anchorSetRel(a: *Anchor, rel: []const u8) !void {
 
 // HTMLLinkElement
 
-pub fn linkGetRel(link: *Link) ![]const u8 {
-    var res: ?*String = null;
-    const err = c.dom_html_link_element_get_rel(link, &res);
-    try DOMErr(err);
-    if (res == null) return "";
-    return strToData(res.?);
-}
-
-pub fn linkSetRel(link: *Link, rel: []const u8) !void {
-    const err = c.dom_html_link_element_set_rel(link, try strFromData(rel));
-    return DOMErr(err);
-}
-
 pub fn linkGetHref(link: *Link) ![]const u8 {
     var res: ?*String = null;
     const err = c.dom_html_link_element_get_href(link, &res);
@@ -2049,7 +2032,7 @@ pub const OptionCollection = c.dom_html_options_collection;
 // Document Fragment
 pub const DocumentFragment = c.dom_document_fragment;
 
-pub fn documentFragmentToNode(doc: *DocumentFragment) *Node {
+pub inline fn documentFragmentToNode(doc: *DocumentFragment) *Node {
     return @as(*Node, @ptrCast(@alignCast(doc)));
 }
 
@@ -2080,29 +2063,29 @@ fn documentTypeVtable(dt: *DocumentType) c.dom_document_type_vtable {
     return getVtable(c.dom_document_type_vtable, DocumentType, dt);
 }
 
-pub fn documentTypeGetName(dt: *DocumentType) ![]const u8 {
+pub inline fn documentTypeGetName(dt: *DocumentType) ![]const u8 {
     var s: ?*String = null;
     const err = documentTypeVtable(dt).dom_document_type_get_name.?(dt, &s);
     try DOMErr(err);
     return strToData(s.?);
 }
 
-pub fn documentTypeGetPublicId(dt: *DocumentType) []const u8 {
+pub inline fn documentTypeGetPublicId(dt: *DocumentType) ![]const u8 {
     var s: ?*String = null;
     const err = documentTypeVtable(dt).dom_document_type_get_public_id.?(dt, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return strToData(s.?);
 }
 
-pub fn documentTypeGetSystemId(dt: *DocumentType) []const u8 {
+pub inline fn documentTypeGetSystemId(dt: *DocumentType) ![]const u8 {
     var s: ?*String = null;
     const err = documentTypeVtable(dt).dom_document_type_get_system_id.?(dt, &s);
-    std.debug.assert(err == c.DOM_NO_ERR);
+    try DOMErr(err);
     return strToData(s.?);
 }
 
 // DOMImplementation
-pub fn domImplementationCreateDocument(
+pub inline fn domImplementationCreateDocument(
     namespace: ?[:0]const u8,
     qname: ?[:0]const u8,
     doctype: ?*DocumentType,
@@ -2132,7 +2115,7 @@ pub fn domImplementationCreateDocument(
     return doc.?;
 }
 
-pub fn domImplementationCreateDocumentType(
+pub inline fn domImplementationCreateDocumentType(
     qname: [:0]const u8,
     publicId: [:0]const u8,
     systemId: [:0]const u8,
@@ -2143,7 +2126,7 @@ pub fn domImplementationCreateDocumentType(
     return dt.?;
 }
 
-pub fn domImplementationCreateHTMLDocument(title: ?[]const u8) !*DocumentHTML {
+pub inline fn domImplementationCreateHTMLDocument(title: ?[]const u8) !*DocumentHTML {
     const doc_html = try documentCreateDocument(title);
     const doc = documentHTMLToDocument(doc_html);
 
@@ -2174,18 +2157,18 @@ fn documentVtable(doc: *Document) c.dom_document_vtable {
     return getVtable(c.dom_document_vtable, Document, doc);
 }
 
-pub fn documentToNode(doc: *Document) *Node {
+pub inline fn documentToNode(doc: *Document) *Node {
     return @as(*Node, @ptrCast(@alignCast(doc)));
 }
 
-pub fn documentGetElementById(doc: *Document, id: []const u8) !?*Element {
+pub inline fn documentGetElementById(doc: *Document, id: []const u8) !?*Element {
     var elem: ?*Element = null;
     const err = documentVtable(doc).dom_document_get_element_by_id.?(doc, try strFromData(id), &elem);
     try DOMErr(err);
     return elem;
 }
 
-pub fn documentGetElementsByTagName(doc: *Document, tagname: []const u8) !*NodeList {
+pub inline fn documentGetElementsByTagName(doc: *Document, tagname: []const u8) !*NodeList {
     var nlist: ?*NodeList = null;
     const err = documentVtable(doc).dom_document_get_elements_by_tag_name.?(doc, try strFromData(tagname), &nlist);
     try DOMErr(err);
@@ -2193,7 +2176,7 @@ pub fn documentGetElementsByTagName(doc: *Document, tagname: []const u8) !*NodeL
 }
 
 // documentGetDocumentElement returns the root document element.
-pub fn documentGetDocumentElement(doc: *Document) !?*Element {
+pub inline fn documentGetDocumentElement(doc: *Document) !?*Element {
     var elem: ?*Element = null;
     const err = documentVtable(doc).dom_document_get_document_element.?(doc, &elem);
     try DOMErr(err);
@@ -2201,7 +2184,7 @@ pub fn documentGetDocumentElement(doc: *Document) !?*Element {
     return elem.?;
 }
 
-pub fn documentGetDocumentURI(doc: *Document) ![]const u8 {
+pub inline fn documentGetDocumentURI(doc: *Document) ![]const u8 {
     var s: ?*String = null;
     const err = documentVtable(doc).dom_document_get_uri.?(doc, &s);
     try DOMErr(err);
@@ -2213,19 +2196,19 @@ pub fn documentSetDocumentURI(doc: *Document, uri: []const u8) !void {
     try DOMErr(err);
 }
 
-pub fn documentGetInputEncoding(doc: *Document) ![]const u8 {
+pub inline fn documentGetInputEncoding(doc: *Document) ![]const u8 {
     var s: ?*String = null;
     const err = documentVtable(doc).dom_document_get_input_encoding.?(doc, &s);
     try DOMErr(err);
     return strToData(s.?);
 }
 
-pub fn documentSetInputEncoding(doc: *Document, enc: []const u8) !void {
+pub inline fn documentSetInputEncoding(doc: *Document, enc: []const u8) !void {
     const err = documentVtable(doc).dom_document_set_input_encoding.?(doc, try strFromData(enc));
     try DOMErr(err);
 }
 
-pub fn documentCreateDocument(title: ?[]const u8) !*DocumentHTML {
+pub inline fn documentCreateDocument(title: ?[]const u8) !*DocumentHTML {
     var doc: ?*Document = null;
     const err = c.dom_implementation_create_document(
         c.DOM_IMPLEMENTATION_HTML,
@@ -2292,42 +2275,42 @@ pub fn documentCreateElementNS(doc: *Document, ns: []const u8, tag_name: []const
     return elem.?;
 }
 
-pub fn documentGetDoctype(doc: *Document) !?*DocumentType {
+pub inline fn documentGetDoctype(doc: *Document) !?*DocumentType {
     var dt: ?*DocumentType = null;
     const err = documentVtable(doc).dom_document_get_doctype.?(doc, &dt);
     try DOMErr(err);
     return dt;
 }
 
-pub fn documentCreateDocumentFragment(doc: *Document) !*DocumentFragment {
+pub inline fn documentCreateDocumentFragment(doc: *Document) !*DocumentFragment {
     var df: ?*DocumentFragment = null;
     const err = documentVtable(doc).dom_document_create_document_fragment.?(doc, &df);
     try DOMErr(err);
     return df.?;
 }
 
-pub fn documentCreateTextNode(doc: *Document, s: []const u8) !*Text {
+pub inline fn documentCreateTextNode(doc: *Document, s: []const u8) !*Text {
     var txt: ?*Text = null;
     const err = documentVtable(doc).dom_document_create_text_node.?(doc, try strFromData(s), &txt);
     try DOMErr(err);
     return txt.?;
 }
 
-pub fn documentCreateCDATASection(doc: *Document, s: []const u8) !*CDATASection {
+pub inline fn documentCreateCDATASection(doc: *Document, s: []const u8) !*CDATASection {
     var cdata: ?*CDATASection = null;
     const err = documentVtable(doc).dom_document_create_cdata_section.?(doc, try strFromData(s), &cdata);
     try DOMErr(err);
     return cdata.?;
 }
 
-pub fn documentCreateComment(doc: *Document, s: []const u8) !*Comment {
+pub inline fn documentCreateComment(doc: *Document, s: []const u8) !*Comment {
     var com: ?*Comment = null;
     const err = documentVtable(doc).dom_document_create_comment.?(doc, try strFromData(s), &com);
     try DOMErr(err);
     return com.?;
 }
 
-pub fn documentCreateProcessingInstruction(doc: *Document, target: []const u8, data: []const u8) !*ProcessingInstruction {
+pub inline fn documentCreateProcessingInstruction(doc: *Document, target: []const u8, data: []const u8) !*ProcessingInstruction {
     var pi: ?*ProcessingInstruction = null;
     const err = documentVtable(doc).dom_document_create_processing_instruction.?(
         doc,
@@ -2339,7 +2322,7 @@ pub fn documentCreateProcessingInstruction(doc: *Document, target: []const u8, d
     return pi.?;
 }
 
-pub fn documentImportNode(doc: *Document, node: *Node, deep: bool) !*Node {
+pub inline fn documentImportNode(doc: *Document, node: *Node, deep: bool) !*Node {
     var res: NodeExternal = undefined;
     const nodeext = toNodeExternal(Node, node);
     const err = documentVtable(doc).dom_document_import_node.?(doc, nodeext, deep, &res);
@@ -2347,7 +2330,7 @@ pub fn documentImportNode(doc: *Document, node: *Node, deep: bool) !*Node {
     return @as(*Node, @ptrCast(@alignCast(res)));
 }
 
-pub fn documentAdoptNode(doc: *Document, node: *Node) !*Node {
+pub inline fn documentAdoptNode(doc: *Document, node: *Node) !*Node {
     var res: NodeExternal = undefined;
     const nodeext = toNodeExternal(Node, node);
     const err = documentVtable(doc).dom_document_adopt_node.?(doc, nodeext, &res);
@@ -2355,14 +2338,14 @@ pub fn documentAdoptNode(doc: *Document, node: *Node) !*Node {
     return @as(*Node, @ptrCast(@alignCast(res)));
 }
 
-pub fn documentCreateAttribute(doc: *Document, name: []const u8) !*Attribute {
+pub inline fn documentCreateAttribute(doc: *Document, name: []const u8) !*Attribute {
     var attr: ?*Attribute = null;
     const err = documentVtable(doc).dom_document_create_attribute.?(doc, try strFromData(name), &attr);
     try DOMErr(err);
     return attr.?;
 }
 
-pub fn documentCreateAttributeNS(doc: *Document, ns: []const u8, qname: []const u8) !*Attribute {
+pub inline fn documentCreateAttributeNS(doc: *Document, ns: []const u8, qname: []const u8) !*Attribute {
     var attr: ?*Attribute = null;
     const err = documentVtable(doc).dom_document_create_attribute_ns.?(
         doc,
@@ -2386,7 +2369,7 @@ pub fn documentSetScriptAddedCallback(
 pub const DocumentHTML = c.dom_html_document;
 
 // documentHTMLToNode is an helper to convert a documentHTML to an node.
-pub fn documentHTMLToNode(doc: *DocumentHTML) *Node {
+pub inline fn documentHTMLToNode(doc: *DocumentHTML) *Node {
     return @as(*Node, @ptrCast(@alignCast(doc)));
 }
 
@@ -2503,22 +2486,31 @@ fn parseParams(enc: ?[:0]const u8) c.dom_hubbub_parser_params {
 }
 
 fn parseData(parser: *c.dom_hubbub_parser, reader: anytype) !void {
-    var buffer: [1024]u8 = undefined;
-    var ln = buffer.len;
-    while (ln > 0) {
-        ln = try reader.read(&buffer);
-        const err = c.dom_hubbub_parser_parse_chunk(parser, &buffer, ln);
-        // TODO handle encoding change error return.
-        // When the HTML contains a META tag with a different encoding than the
-        // original one, a c.DOM_HUBBUB_HUBBUB_ERR_ENCODINGCHANGE error is
-        // returned.
-        // In this case, we must restart the parsing with the new detected
-        // encoding. The detected encoding is stored in the document and we can
-        // get it with documentGetInputEncoding().
-        try parserErr(err);
+    var err: c.hubbub_error = undefined;
+    const TI = @typeInfo(@TypeOf(reader));
+    if (TI == .pointer and @hasDecl(TI.pointer.child, "next")) {
+        while (try reader.next()) |data| {
+            err = c.dom_hubbub_parser_parse_chunk(parser, data.ptr, data.len);
+            try parserErr(err);
+        }
+    } else {
+        var buffer: [1024]u8 = undefined;
+        var ln = buffer.len;
+        while (ln > 0) {
+            ln = try reader.read(&buffer);
+            err = c.dom_hubbub_parser_parse_chunk(parser, &buffer, ln);
+            // TODO handle encoding change error return.
+            // When the HTML contains a META tag with a different encoding than the
+            // original one, a c.DOM_HUBBUB_HUBBUB_ERR_ENCODINGCHANGE error is
+            // returned.
+            // In this case, we must restart the parsing with the new detected
+            // encoding. The detected encoding is stored in the document and we can
+            // get it with documentGetInputEncoding().
+            try parserErr(err);
+        }
     }
-    const err = c.dom_hubbub_parser_completed(parser);
-    return parserErr(err);
+    err = c.dom_hubbub_parser_completed(parser);
+    try parserErr(err);
 }
 
 // documentHTMLClose closes the document.
@@ -2527,11 +2519,11 @@ pub fn documentHTMLClose(doc: *DocumentHTML) !void {
     try DOMErr(err);
 }
 
-pub fn documentHTMLToDocument(doc_html: *DocumentHTML) *Document {
+pub inline fn documentHTMLToDocument(doc_html: *DocumentHTML) *Document {
     return @as(*Document, @ptrCast(doc_html));
 }
 
-pub fn documentHTMLBody(doc_html: *DocumentHTML) !?*Body {
+pub inline fn documentHTMLBody(doc_html: *DocumentHTML) !?*Body {
     var body: ?*ElementHTML = null;
     const err = documentHTMLVtable(doc_html).get_body.?(doc_html, &body);
     try DOMErr(err);
@@ -2539,16 +2531,16 @@ pub fn documentHTMLBody(doc_html: *DocumentHTML) !?*Body {
     return @as(*Body, @ptrCast(body.?));
 }
 
-pub fn bodyToElement(body: *Body) *Element {
+pub inline fn bodyToElement(body: *Body) *Element {
     return @as(*Element, @ptrCast(@alignCast(body)));
 }
 
-pub fn documentHTMLSetBody(doc_html: *DocumentHTML, elt: ?*ElementHTML) !void {
+pub inline fn documentHTMLSetBody(doc_html: *DocumentHTML, elt: ?*ElementHTML) !void {
     const err = documentHTMLVtable(doc_html).set_body.?(doc_html, elt);
     try DOMErr(err);
 }
 
-pub fn documentHTMLGetReferrer(doc: *DocumentHTML) ![]const u8 {
+pub inline fn documentHTMLGetReferrer(doc: *DocumentHTML) ![]const u8 {
     var s: ?*String = null;
     const err = documentHTMLVtable(doc).get_referrer.?(doc, &s);
     try DOMErr(err);
@@ -2556,7 +2548,7 @@ pub fn documentHTMLGetReferrer(doc: *DocumentHTML) ![]const u8 {
     return strToData(s.?);
 }
 
-pub fn documentHTMLGetTitle(doc: *DocumentHTML) ![]const u8 {
+pub inline fn documentHTMLGetTitle(doc: *DocumentHTML) ![]const u8 {
     var s: ?*String = null;
     const err = documentHTMLVtable(doc).get_title.?(doc, &s);
     try DOMErr(err);
@@ -2564,7 +2556,7 @@ pub fn documentHTMLGetTitle(doc: *DocumentHTML) ![]const u8 {
     return strToData(s.?);
 }
 
-pub fn documentHTMLSetTitle(doc: *DocumentHTML, v: []const u8) !void {
+pub inline fn documentHTMLSetTitle(doc: *DocumentHTML, v: []const u8) !void {
     const err = documentHTMLVtable(doc).set_title.?(doc, try strFromData(v));
     try DOMErr(err);
 }

src/browser/page.zig

@@ -23,8 +23,8 @@ const Allocator = std.mem.Allocator;
 
 const Dump = @import("dump.zig");
 const State = @import("State.zig");
+const Env = @import("env.zig").Env;
 const Mime = @import("mime.zig").Mime;
-const Browser = @import("browser.zig").Browser;
 const Session = @import("session.zig").Session;
 const Renderer = @import("renderer.zig").Renderer;
 const Window = @import("html/window.zig").Window;
@@ -32,13 +32,8 @@ const Walker = @import("dom/walker.zig").WalkerDepthFirst;
 const Scheduler = @import("Scheduler.zig");
 const Http = @import("../http/Http.zig");
 const ScriptManager = @import("ScriptManager.zig");
-const SlotChangeMonitor = @import("SlotChangeMonitor.zig");
 const HTMLDocument = @import("html/document.zig").HTMLDocument;
 
-const NavigationKind = @import("navigation/navigation.zig").NavigationKind;
-const NavigationCurrentEntryChangeEvent = @import("navigation/navigation.zig").NavigationCurrentEntryChangeEvent;
-
-const js = @import("js/js.zig");
 const URL = @import("../url.zig").URL;
 
 const log = @import("../log.zig");
@@ -78,7 +73,7 @@ pub const Page = struct {
 
     // Our JavaScript context for this specific page. This is what we use to
     // execute any JavaScript
-    js: *js.Context,
+    main_context: *Env.JsContext,
 
     // indicates intention to navigate to another page on the next loop execution.
     delayed_navigation: bool = false,
@@ -95,10 +90,6 @@ pub const Page = struct {
 
     load_state: LoadState = .parsing,
 
-    // expensive, adds a a global MutationObserver, so we only do it if there's
-    // an "slotchange" event registered
-    slot_change_monitor: ?*SlotChangeMonitor = null,
-
     notified_network_idle: IdleNotification = .init,
     notified_network_almost_idle: IdleNotification = .init,
 
@@ -125,7 +116,7 @@ pub const Page = struct {
         complete,
     };
 
-    pub fn init(self: *Page, arena: Allocator, call_arena: Allocator, session: *Session) !void {
+    pub fn init(self: *Page, arena: Allocator, session: *Session) !void {
         const browser = session.browser;
         const script_manager = ScriptManager.init(browser, self);
 
@@ -135,7 +126,7 @@ pub const Page = struct {
             .window = try Window.create(null, null),
             .arena = arena,
             .session = session,
-            .call_arena = call_arena,
+            .call_arena = undefined,
             .renderer = Renderer.init(arena),
             .state_pool = &browser.state_pool,
             .cookie_jar = &session.cookie_jar,
@@ -144,13 +135,17 @@ pub const Page = struct {
             .scheduler = Scheduler.init(arena),
             .keydown_event_node = .{ .func = keydownCallback },
             .window_clicked_event_node = .{ .func = windowClicked },
-            .js = undefined,
+            .main_context = undefined,
         };
 
-        self.js = try session.executor.createContext(self, true, js.GlobalMissingCallback.init(&self.polyfill_loader));
-        try polyfill.preload(self.arena, self.js);
+        self.main_context = try session.executor.createJsContext(&self.window, self, self, true, Env.GlobalMissingCallback.init(&self.polyfill_loader));
+        try polyfill.preload(self.arena, self.main_context);
 
-        try self.registerBackgroundTasks();
+        try self.scheduler.add(self, runMicrotasks, 5, .{ .name = "page.microtasks" });
+        // message loop must run only non-test env
+        if (comptime !builtin.is_test) {
+            try self.scheduler.add(self, runMessageLoop, 5, .{ .name = "page.messageLoop" });
+        }
     }
 
     pub fn deinit(self: *Page) void {
@@ -160,10 +155,7 @@ pub const Page = struct {
         self.script_manager.deinit();
     }
 
-    fn reset(self: *Page) !void {
-        // Force running the micro task to drain the queue.
-        self.session.browser.env.runMicrotasks();
-
+    fn reset(self: *Page) void {
         self.scheduler.reset();
         self.http_client.abort();
         self.script_manager.reset();
@@ -171,38 +163,25 @@ pub const Page = struct {
         self.load_state = .parsing;
         self.mode = .{ .pre = {} };
         _ = self.session.browser.page_arena.reset(.{ .retain_with_limit = 1 * 1024 * 1024 });
-
-        try self.registerBackgroundTasks();
     }
 
-    fn registerBackgroundTasks(self: *Page) !void {
-        if (comptime builtin.is_test) {
-            // HTML test runner manually calls these as necessary
-            return;
-        }
+    fn runMicrotasks(ctx: *anyopaque) ?u32 {
+        const self: *Page = @ptrCast(@alignCast(ctx));
+        self.session.browser.runMicrotasks();
+        return 5;
+    }
 
-        try self.scheduler.add(self.session.browser, struct {
-            fn runMicrotasks(ctx: *anyopaque) ?u32 {
-                const b: *Browser = @ptrCast(@alignCast(ctx));
-                b.runMicrotasks();
-                return 5;
-            }
-        }.runMicrotasks, 5, .{ .name = "page.microtasks" });
-
-        try self.scheduler.add(self.session.browser, struct {
-            fn runMessageLoop(ctx: *anyopaque) ?u32 {
-                const b: *Browser = @ptrCast(@alignCast(ctx));
-                b.runMessageLoop();
-                return 100;
-            }
-        }.runMessageLoop, 5, .{ .name = "page.messageLoop" });
+    fn runMessageLoop(ctx: *anyopaque) ?u32 {
+        const self: *Page = @ptrCast(@alignCast(ctx));
+        self.session.browser.runMessageLoop();
+        return 100;
     }
 
     pub const DumpOpts = struct {
         // set to include element shadowroots in the dump
         page: ?*const Page = null,
         with_base: bool = false,
-        strip_mode: Dump.Opts.StripMode = .{},
+        exclude_scripts: bool = false,
     };
 
     // dump writes the page content into the given file.
@@ -219,12 +198,12 @@ pub const Page = struct {
                 // returns the <pre> element from the HTML
                 const doc = parser.documentHTMLToDocument(self.window.document);
                 const list = try parser.documentGetElementsByTagName(doc, "pre");
-                const pre = parser.nodeListItem(list, 0) orelse return error.InvalidHTML;
+                const pre = try parser.nodeListItem(list, 0) orelse return error.InvalidHTML;
                 const walker = Walker{};
                 var next: ?*parser.Node = null;
                 while (true) {
                     next = try walker.get_next(pre, next) orelse break;
-                    const v = parser.nodeTextContent(next.?) orelse return;
+                    const v = try parser.nodeTextContent(next.?) orelse return;
                     try out.writeAll(v);
                 }
                 return;
@@ -249,7 +228,7 @@ pub const Page = struct {
 
         try Dump.writeHTML(doc, .{
             .page = opts.page,
-            .strip_mode = opts.strip_mode,
+            .exclude_scripts = opts.exclude_scripts,
         }, out);
     }
 
@@ -262,7 +241,7 @@ pub const Page = struct {
 
         // find <head> tag
         const list = try parser.documentGetElementsByTagName(doc, "head");
-        const head = parser.nodeListItem(list, 0) orelse return;
+        const head = try parser.nodeListItem(list, 0) orelse return;
 
         const base = try parser.documentCreateElement(doc, "base");
         try parser.elementSetAttribute(base, "href", self.url.raw);
@@ -271,6 +250,11 @@ pub const Page = struct {
         try Node.prepend(head, &[_]Node.NodeOrText{.{ .node = parser.elementToNode(base) }});
     }
 
+    pub fn fetchModuleSource(ctx: *anyopaque, src: [:0]const u8) !ScriptManager.BlockingResult {
+        const self: *Page = @ptrCast(@alignCast(ctx));
+        return self.script_manager.blockingGet(src);
+    }
+
     pub fn wait(self: *Page, wait_ms: i32) Session.WaitResult {
         return self._wait(wait_ms) catch |err| {
             switch (err) {
@@ -292,8 +276,8 @@ pub const Page = struct {
         var timer = try std.time.Timer.start();
         var ms_remaining = wait_ms;
 
-        var try_catch: js.TryCatch = undefined;
-        try_catch.init(self.js);
+        var try_catch: Env.TryCatch = undefined;
+        try_catch.init(self.main_context);
         defer try_catch.deinit();
 
         var scheduler = &self.scheduler;
@@ -328,12 +312,6 @@ pub const Page = struct {
                     // mode with an extra socket. Either way, we're waiting
                     // for http traffic
                     if (try http_client.tick(ms_remaining) == .extra_socket) {
-                        // exit_when_done is explicitly set when there isn't
-                        // an extra socket, so it should not be possibl to
-                        // get an extra_socket message when exit_when_done
-                        // is true.
-                        std.debug.assert(exit_when_done == false);
-
                         // data on a socket we aren't handling, return to caller
                         return .extra_socket;
                     }
@@ -369,7 +347,11 @@ pub const Page = struct {
                         std.debug.assert(http_client.intercepted == 0);
 
                         const ms = ms_to_next_task orelse blk: {
-                            if (wait_ms - ms_remaining < 100) {
+                            // TODO: when jsRunner is fully replaced with the
+                            // htmlRunner, we can remove the first part of this
+                            // condition. jsRunner calls `page.wait` far too
+                            // often to enforce this.
+                            if (wait_ms > 100 and wait_ms - ms_remaining < 100) {
                                 // Look, we want to exit ASAP, but we don't want
                                 // to exit so fast that we've run none of the
                                 // background jobs.
@@ -542,7 +524,7 @@ pub const Page = struct {
         if (self.mode != .pre) {
             // it's possible for navigate to be called multiple times on the
             // same page (via CDP). We want to reset the page between each call.
-            try self.reset();
+            self.reset();
         }
 
         log.info(.http, "navigate", .{
@@ -566,7 +548,7 @@ pub const Page = struct {
         const owned_url = try self.arena.dupeZ(u8, request_url);
         self.url = try URL.parse(owned_url, null);
 
-        var headers = try self.http_client.newHeaders();
+        var headers = try Http.Headers.init();
         if (opts.header) |hdr| try headers.add(hdr);
         try self.requestCookie(.{ .is_navigation = true }).headersForRequest(self.arena, owned_url, &headers);
 
@@ -801,7 +783,7 @@ pub const Page = struct {
                         // ignore non-js script.
                         continue;
                     }
-                    try self.script_manager.addFromElement(@ptrCast(node), "page");
+                    try self.script_manager.addFromElement(@ptrCast(node));
                 }
 
                 self.script_manager.staticScriptsDone();
@@ -817,9 +799,6 @@ pub const Page = struct {
                 unreachable;
             },
         }
-
-        // We need to handle different navigation types differently.
-        try self.session.navigation.processNavigation(self);
     }
 
     fn pageErrorCallback(ctx: *anyopaque, err: anyerror) void {
@@ -852,7 +831,7 @@ pub const Page = struct {
         _ = self.session.browser.transfer_arena.reset(.{ .retain_with_limit = 4 * 1024 });
     }
 
-    // extracted because this is called from tests to set things up.
+    // extracted because this sis called from tests to set things up.
     pub fn setDocument(self: *Page, html_doc: *parser.DocumentHTML) !void {
         const doc = parser.documentHTMLToDocument(html_doc);
         try parser.documentSetDocumentURI(doc, self.url.raw);
@@ -909,7 +888,7 @@ pub const Page = struct {
             .a => {
                 const element: *parser.Element = @ptrCast(node);
                 const href = (try parser.elementGetAttribute(element, "href")) orelse return;
-                try self.navigateFromWebAPI(href, .{}, .{ .push = null });
+                try self.navigateFromWebAPI(href, .{});
             },
             .input => {
                 const element: *parser.Element = @ptrCast(node);
@@ -1016,55 +995,13 @@ pub const Page = struct {
         }
     }
 
-    // insertText is a shortcut to insert text into the active element.
-    pub fn insertText(self: *Page, v: []const u8) !void {
-        const Document = @import("dom/document.zig").Document;
-        const element = (try Document.getActiveElement(@ptrCast(self.window.document), self)) orelse return;
-        const node = parser.elementToNode(element);
-
-        const tag = (try parser.nodeHTMLGetTagType(node)) orelse return;
-        switch (tag) {
-            .input => {
-                const input_type = try parser.inputGetType(@ptrCast(element));
-                if (std.mem.eql(u8, input_type, "text")) {
-                    const value = try parser.inputGetValue(@ptrCast(element));
-                    const new_value = try std.mem.concat(self.arena, u8, &.{ value, v });
-                    try parser.inputSetValue(@ptrCast(element), new_value);
-                }
-            },
-            .textarea => {
-                const value = try parser.textareaGetValue(@ptrCast(node));
-                const new_value = try std.mem.concat(self.arena, u8, &.{ value, v });
-                try parser.textareaSetValue(@ptrCast(node), new_value);
-            },
-            else => {},
-        }
-    }
-
     // We cannot navigate immediately as navigating will delete the DOM tree,
     // which holds this event's node.
     // As such we schedule the function to be called as soon as possible.
     // The page.arena is safe to use here, but the transfer_arena exists
     // specifically for this type of lifetime.
-    pub fn navigateFromWebAPI(self: *Page, url: []const u8, opts: NavigateOpts, kind: NavigationKind) !void {
+    pub fn navigateFromWebAPI(self: *Page, url: []const u8, opts: NavigateOpts) !void {
         const session = self.session;
-        const stitched_url = try URL.stitch(session.transfer_arena, url, self.url.raw, .{ .alloc = .always });
-
-        // Force will force a page load.
-        // Otherwise, we need to check if this is a true navigation.
-        if (!opts.force) {
-            // If we are navigating within the same document, just change URL.
-            const new_url = try URL.parse(stitched_url, null);
-
-            if (try self.url.eqlDocument(&new_url, session.transfer_arena)) {
-                self.url = new_url;
-
-                const prev = session.navigation.currentEntry();
-                NavigationCurrentEntryChangeEvent.dispatch(&self.session.navigation, prev, kind);
-                return;
-            }
-        }
-
         if (session.queued_navigation != null) {
             // It might seem like this should never happen. And it might not,
             // BUT..consider the case where we have script like:
@@ -1087,11 +1024,9 @@ pub const Page = struct {
 
         session.queued_navigation = .{
             .opts = opts,
-            .url = stitched_url,
+            .url = try URL.stitch(session.transfer_arena, url, self.url.raw, .{ .alloc = .always }),
         };
 
-        session.navigation_kind = kind;
-
         self.http_client.abort();
 
         // In v8, this throws an exception which JS code cannot catch.
@@ -1142,12 +1077,12 @@ pub const Page = struct {
         } else {
             action = try URL.concatQueryString(transfer_arena, action, buf.items);
         }
-        try self.navigateFromWebAPI(action, opts, .{ .push = null });
+        try self.navigateFromWebAPI(action, opts);
     }
 
-    pub fn isNodeAttached(self: *const Page, node: *parser.Node) bool {
+    pub fn isNodeAttached(self: *const Page, node: *parser.Node) !bool {
         const root = parser.documentToNode(parser.documentHTMLToDocument(self.window.document));
-        return root == parser.nodeGetRootNode(node);
+        return root == try parser.nodeGetRootNode(node);
     }
 
     fn elementSubmitForm(self: *Page, element: *parser.Element) !void {
@@ -1176,22 +1111,10 @@ pub const Page = struct {
 
     pub fn stackTrace(self: *Page) !?[]const u8 {
         if (comptime builtin.mode == .Debug) {
-            return self.js.stackTrace();
+            return self.main_context.stackTrace();
         }
         return null;
     }
-
-    pub fn registerSlotChangeMonitor(self: *Page) !void {
-        if (self.slot_change_monitor != null) {
-            return;
-        }
-        self.slot_change_monitor = try SlotChangeMonitor.init(self);
-    }
-
-    pub fn isSameOrigin(self: *const Page, url: []const u8) !bool {
-        const current_origin = try self.origin(self.call_arena);
-        return std.mem.startsWith(u8, url, current_origin);
-    }
 };
 
 pub const NavigateReason = enum {
@@ -1199,8 +1122,6 @@ pub const NavigateReason = enum {
     address_bar,
     form,
     script,
-    history,
-    navigation,
 };
 
 pub const NavigateOpts = struct {
@@ -1209,7 +1130,6 @@ pub const NavigateOpts = struct {
     method: Http.Method = .GET,
     body: ?[]const u8 = null,
     header: ?[:0]const u8 = null,
-    force: bool = false,
 };
 
 const IdleNotification = union(enum) {
@@ -1312,7 +1232,7 @@ pub export fn scriptAddedCallback(ctx: ?*anyopaque, element: ?*parser.Element) c
     // here, else the script_manager will flag it as already-processed.
     _ = parser.elementGetAttribute(element.?, "src") catch return orelse return;
 
-    self.script_manager.addFromElement(element.?, "dynamic") catch |err| {
+    self.script_manager.addFromElement(element.?) catch |err| {
         log.warn(.browser, "dynamic script", .{ .err = err });
     };
 }

src/browser/polyfill/polyfill.zig

@@ -19,9 +19,9 @@
 const std = @import("std");
 const builtin = @import("builtin");
 
-const js = @import("../js/js.zig");
 const log = @import("../../log.zig");
 const Allocator = std.mem.Allocator;
+const Env = @import("../env.zig").Env;
 
 pub const Loader = struct {
     state: enum { empty, loading } = .empty,
@@ -30,8 +30,8 @@ pub const Loader = struct {
         webcomponents: bool = false,
     } = .{},
 
-    fn load(self: *Loader, comptime name: []const u8, source: []const u8, js_context: *js.Context) void {
-        var try_catch: js.TryCatch = undefined;
+    fn load(self: *Loader, comptime name: []const u8, source: []const u8, js_context: *Env.JsContext) void {
+        var try_catch: Env.TryCatch = undefined;
         try_catch.init(js_context);
         defer try_catch.deinit();
 
@@ -49,7 +49,7 @@ pub const Loader = struct {
         @field(self.done, name) = true;
     }
 
-    pub fn missing(self: *Loader, name: []const u8, js_context: *js.Context) bool {
+    pub fn missing(self: *Loader, name: []const u8, js_context: *Env.JsContext) bool {
         // Avoid recursive calls during polyfill loading.
         if (self.state == .loading) {
             return false;
@@ -69,7 +69,6 @@ pub const Loader = struct {
         if (comptime builtin.mode == .Debug) {
             log.debug(.unknown_prop, "unkown global property", .{
                 .info = "but the property can exist in pure JS",
-                .stack = js_context.stackTrace() catch "???",
                 .property = name,
             });
         }
@@ -83,8 +82,8 @@ pub const Loader = struct {
     }
 };
 
-pub fn preload(allocator: Allocator, js_context: *js.Context) !void {
-    var try_catch: js.TryCatch = undefined;
+pub fn preload(allocator: Allocator, js_context: *Env.JsContext) !void {
+    var try_catch: Env.TryCatch = undefined;
     try_catch.init(js_context);
     defer try_catch.deinit();
 

src/browser/session.zig

@@ -20,13 +20,11 @@ const std = @import("std");
 
 const Allocator = std.mem.Allocator;
 
-const js = @import("js/js.zig");
+const Env = @import("env.zig").Env;
 const Page = @import("page.zig").Page;
-const NavigationKind = @import("navigation/navigation.zig").NavigationKind;
+const URL = @import("../url.zig").URL;
 const Browser = @import("browser.zig").Browser;
 const NavigateOpts = @import("page.zig").NavigateOpts;
-const History = @import("html/History.zig");
-const Navigation = @import("navigation/Navigation.zig");
 
 const log = @import("../log.zig");
 const parser = @import("netsurf.zig");
@@ -52,16 +50,10 @@ pub const Session = struct {
     // page and start another.
     transfer_arena: Allocator,
 
-    executor: js.ExecutionWorld,
+    executor: Env.ExecutionWorld,
     storage_shed: storage.Shed,
     cookie_jar: storage.CookieJar,
 
-    // History is persistent across the "tab".
-    // https://developer.mozilla.org/en-US/docs/Web/API/History
-    history: History = .{},
-    navigation: Navigation = .{},
-    navigation_kind: ?NavigationKind = null,
-
     page: ?Page = null,
 
     // If the current page want to navigate to a new page
@@ -102,7 +94,7 @@ pub const Session = struct {
 
         // Start netsurf memory arena.
         // We need to init this early as JS event handlers may be registered through Runtime.evaluate before the first html doc is loaded
-        parser.init();
+        try parser.init();
 
         const page_arena = &self.browser.page_arena;
         _ = page_arena.reset(.{ .retain_with_limit = 1 * 1024 * 1024 });
@@ -110,7 +102,7 @@ pub const Session = struct {
 
         self.page = @as(Page, undefined);
         const page = &self.page.?;
-        try Page.init(page, page_arena.allocator(), self.browser.call_arena.allocator(), self);
+        try Page.init(page, page_arena.allocator(), self);
 
         log.debug(.browser, "create page", .{});
         // start JS env
@@ -130,7 +122,7 @@ pub const Session = struct {
         // registered a destructor (e.g. XMLHttpRequest).
         // Should be called before we deinit the page, because these objects
         // could be referencing it.
-        self.executor.removeContext();
+        self.executor.removeJsContext();
 
         self.page.?.deinit();
         self.page = null;
@@ -152,63 +144,36 @@ pub const Session = struct {
     };
 
     pub fn wait(self: *Session, wait_ms: i32) WaitResult {
-        _ = self.processQueuedNavigation() catch {
-            // There was an error processing the queue navigation. This already
-            // logged the error, just return.
-            return .done;
-        };
+        if (self.queued_navigation) |qn| {
+            // This was already aborted on the page, but it would be pretty
+            // bad if old requests went to the new page, so let's make double sure
+            self.browser.http_client.abort();
+
+            // Page.navigateFromWebAPI terminatedExecution. If we don't resume
+            // it before doing a shutdown we'll get an error.
+            self.executor.resumeExecution();
+            self.removePage();
+            self.queued_navigation = null;
+
+            const page = self.createPage() catch |err| {
+                log.err(.browser, "queued navigation page error", .{
+                    .err = err,
+                    .url = qn.url,
+                });
+                return .done;
+            };
+
+            page.navigate(qn.url, qn.opts) catch |err| {
+                log.err(.browser, "queued navigation error", .{ .err = err, .url = qn.url });
+                return .done;
+            };
+        }
 
         if (self.page) |*page| {
             return page.wait(wait_ms);
         }
         return .no_page;
     }
-
-    pub fn fetchWait(self: *Session, wait_ms: i32) void {
-        while (true) {
-            if (self.page == null) {
-                return;
-            }
-            _ = self.page.?.wait(wait_ms);
-            const navigated = self.processQueuedNavigation() catch {
-                // There was an error processing the queue navigation. This already
-                // logged the error, just return.
-                return;
-            };
-
-            if (navigated == false) {
-                return;
-            }
-        }
-    }
-
-    fn processQueuedNavigation(self: *Session) !bool {
-        const qn = self.queued_navigation orelse return false;
-        // This was already aborted on the page, but it would be pretty
-        // bad if old requests went to the new page, so let's make double sure
-        self.browser.http_client.abort();
-
-        // Page.navigateFromWebAPI terminatedExecution. If we don't resume
-        // it before doing a shutdown we'll get an error.
-        self.executor.resumeExecution();
-        self.removePage();
-        self.queued_navigation = null;
-
-        const page = self.createPage() catch |err| {
-            log.err(.browser, "queued navigation page error", .{
-                .err = err,
-                .url = qn.url,
-            });
-            return err;
-        };
-
-        page.navigate(qn.url, qn.opts) catch |err| {
-            log.err(.browser, "queued navigation error", .{ .err = err, .url = qn.url });
-            return err;
-        };
-
-        return true;
-    }
 };
 
 const QueuedNavigation = struct {