Merge pull request #1995 from lightpanda-io/ci-wba-test

ci: don't run wba test on PR

.github/workflows/e2e-integration-test.yml

@@ -27,7 +27,7 @@ jobs:
       - uses: ./.github/actions/install
 
       - name: zig build release
-        run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
+        run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64
 
       - name: upload artifact
         uses: actions/upload-artifact@v7
@@ -61,6 +61,6 @@ jobs:
 
       - name: run end to end integration tests
         run: |
-          ./lightpanda serve --log_level error & echo $! > LPD.pid
+          ./lightpanda serve --log-level error & echo $! > LPD.pid
           go run integration/main.go
           kill `cat LPD.pid`

.github/workflows/e2e-test.yml

@@ -52,7 +52,7 @@ jobs:
       - uses: ./.github/actions/install
 
       - name: zig build release
-        run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
+        run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64
 
       - name: upload artifact
         uses: actions/upload-artifact@v7
@@ -98,7 +98,7 @@ jobs:
       - name: run end to end tests through proxy
         run: |
           ./proxy/proxy & echo $! > PROXY.id
-          ./lightpanda serve --http_proxy 'http://127.0.0.1:3000' & echo $! > LPD.pid
+          ./lightpanda serve --http-proxy 'http://127.0.0.1:3000' & echo $! > LPD.pid
           go run runner/main.go
           kill `cat LPD.pid` `cat PROXY.id`
 
@@ -139,9 +139,9 @@ jobs:
       - name: run end to end tests
         run: |
           ./lightpanda serve \
-            --web_bot_auth_key_file private_key.pem \
+            --web-bot-auth-key-file private_key.pem \
-            --web_bot_auth_keyid ${{ vars.WBA_KEY_ID }} \
+            --web-bot-auth-keyid ${{ vars.WBA_KEY_ID }} \
-            --web_bot_auth_domain ${{ vars.WBA_DOMAIN }} \
+            --web-bot-auth-domain ${{ vars.WBA_DOMAIN }} \
             & echo $! > LPD.pid
           go run runner/main.go
           kill `cat LPD.pid`
@@ -155,10 +155,10 @@ jobs:
         run: |
           ./proxy/proxy & echo $! > PROXY.id
           ./lightpanda serve \
-            --web_bot_auth_key_file private_key.pem \
+            --web-bot-auth-key-file private_key.pem \
-            --web_bot_auth_keyid ${{ vars.WBA_KEY_ID }} \
+            --web-bot-auth-keyid ${{ vars.WBA_KEY_ID }} \
-            --web_bot_auth_domain ${{ vars.WBA_DOMAIN }} \
+            --web-bot-auth-domain ${{ vars.WBA_DOMAIN }} \
-            --http_proxy 'http://127.0.0.1:3000' \
+            --http-proxy 'http://127.0.0.1:3000' \
             & echo $! > LPD.pid
           go run runner/main.go
           kill `cat LPD.pid` `cat PROXY.id`
@@ -179,6 +179,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
 
+    # Don't execute on PR
+    if: github.event_name != 'pull_request'
+
     steps:
       - uses: actions/checkout@v6
         with:
@@ -205,9 +208,9 @@ jobs:
           exec 3<<< "${{ secrets.WBA_PRIVATE_KEY_PEM }}"
 
           ./lightpanda fetch --dump http://127.0.0.1:8989/ \
-            --web_bot_auth_key_file /proc/self/fd/3 \
+            --web-bot-auth-key-file /proc/self/fd/3 \
-            --web_bot_auth_keyid ${{ vars.WBA_KEY_ID }} \
+            --web-bot-auth-keyid ${{ vars.WBA_KEY_ID }} \
-            --web_bot_auth_domain ${{ vars.WBA_DOMAIN }}
+            --web-bot-auth-domain ${{ vars.WBA_DOMAIN }}
 
           wait $VALIDATOR_PID
           exec 3>&-

.github/workflows/nightly.yml

@@ -7,7 +7,7 @@ env:
   AWS_REGION: ${{ vars.NIGHTLY_BUILD_AWS_REGION }}
 
   RELEASE: ${{ github.ref_type == 'tag' && github.ref_name || 'nightly' }}
-  GIT_VERSION_FLAG: ${{ github.ref_type == 'tag' && format('-Dgit_version={0}', github.ref_name) || '' }}
+  VERSION: ${{ github.ref_type == 'tag' && github.ref_name || '1.0.0-nightly' }}
 
 on:
   push:
@@ -45,7 +45,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 -Dgit_commit=$(git rev-parse --short ${{ github.sha }}) ${{ env.GIT_VERSION_FLAG }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=x86_64 -Dversion_string=${{ env.VERSION }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -85,7 +85,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic -Dgit_commit=$(git rev-parse --short ${{ github.sha }}) ${{ env.GIT_VERSION_FLAG }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic -Dversion_string=${{ env.VERSION }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -127,7 +127,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dgit_commit=$(git rev-parse --short ${{ github.sha }}) ${{ env.GIT_VERSION_FLAG }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dversion_string=${{ env.VERSION }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}
@@ -167,7 +167,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dgit_commit=$(git rev-parse --short ${{ github.sha }}) ${{ env.GIT_VERSION_FLAG }}
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dversion_string=${{ env.VERSION }}
 
       - name: Rename binary
         run: mv zig-out/bin/lightpanda lightpanda-${{ env.ARCH }}-${{ env.OS }}

.github/workflows/wpt.yml

@@ -14,8 +14,6 @@ on:
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
-  pull_request:
-    types: [opened, synchronize, reopened, ready_for_review]
 
 jobs:
   wpt-build-release:
@@ -42,7 +40,7 @@ jobs:
         run: zig build -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast snapshot_creator -- src/snapshot.bin
 
       - name: zig build release
-        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
+        run: zig build -Dsnapshot_path=../../snapshot.bin -Dprebuilt_v8_path=v8/libc_v8.a -Doptimize=ReleaseFast -Dcpu=generic
 
       - name: upload artifact
         uses: actions/upload-artifact@v7
@@ -118,7 +116,7 @@ jobs:
         run: |
           ./wpt serve 2> /dev/null & echo $! > WPT.pid
           sleep 20s
-          ./wptrunner -lpd-path ./lightpanda -json -concurrency 10 -pool 10 --mem-limit 400 > wpt.json
+          ./wptrunner -lpd-path ./lightpanda -json -concurrency 5 -pool 5 --mem-limit 400 > wpt.json
           kill `cat WPT.pid`
 
       - name: write commit

Dockerfile

@@ -53,8 +53,7 @@ RUN zig build -Doptimize=ReleaseFast \
 # build release
 RUN zig build -Doptimize=ReleaseFast \
     -Dsnapshot_path=../../snapshot.bin \
-    -Dprebuilt_v8_path=v8/libc_v8.a \
+    -Dprebuilt_v8_path=v8/libc_v8.a
-    -Dgit_commit=$(git rev-parse --short HEAD)
 
 FROM debian:stable-slim
 
@@ -75,4 +74,4 @@ EXPOSE 9222/tcp
 # Using "tini" as PID1 ensures that signals work as expected, so e.g. "docker stop" will not hang.
 # (See https://github.com/krallin/tini#why-tini).
 ENTRYPOINT ["/usr/bin/tini", "--"]
-CMD ["/bin/lightpanda", "serve", "--host", "0.0.0.0", "--port", "9222", "--log_level", "info"]
+CMD ["/bin/lightpanda", "serve", "--host", "0.0.0.0", "--port", "9222", "--log-level", "info"]

LICENSING.md

@@ -4,11 +4,3 @@ License names used in this document are as per [SPDX License
 List](https://spdx.org/licenses/).
 
 The default license for this project is [AGPL-3.0-only](LICENSE).
-
-The following directories and their subdirectories are licensed under their
-original upstream licenses:
-
-```
-vendor/
-tests/wpt/
-```

Makefile

@@ -58,13 +58,13 @@ build-v8-snapshot:
 ## Build in release-fast mode
 build: build-v8-snapshot
 	@printf "\033[36mBuilding (release fast)...\033[0m\n"
-	@$(ZIG) build -Doptimize=ReleaseFast -Dsnapshot_path=../../snapshot.bin -Dgit_commit=$$(git rev-parse --short HEAD) || (printf "\033[33mBuild ERROR\033[0m\n"; exit 1;)
+	@$(ZIG) build -Doptimize=ReleaseFast -Dsnapshot_path=../../snapshot.bin || (printf "\033[33mBuild ERROR\033[0m\n"; exit 1;)
 	@printf "\033[33mBuild OK\033[0m\n"
 
 ## Build in debug mode
 build-dev:
 	@printf "\033[36mBuilding (debug)...\033[0m\n"
-	@$(ZIG) build -Dgit_commit=$$(git rev-parse --short HEAD) || (printf "\033[33mBuild ERROR\033[0m\n"; exit 1;)
+	@$(ZIG) build || (printf "\033[33mBuild ERROR\033[0m\n"; exit 1;)
 	@printf "\033[33mBuild OK\033[0m\n"
 
 ## Run the server in release mode

README.md

@@ -18,15 +18,15 @@ Not a Chromium fork. Not a WebKit patch. A new browser, written in Zig.
 </div>
 <div align="center">
 
-[<img width="350px" src="https://cdn.lightpanda.io/assets/images/github/execution-time.svg">
+[<img width="350px" src="https://cdn.lightpanda.io/assets/images/github/execution-time-v2.svg">
 ](https://github.com/lightpanda-io/demo)
 &emsp;
-[<img width="350px" src="https://cdn.lightpanda.io/assets/images/github/memory-frame.svg">
+[<img width="350px" src="https://cdn.lightpanda.io/assets/images/github/memory-frame-v2.svg">
 ](https://github.com/lightpanda-io/demo)
 </div>
 
-_Puppeteer requesting 100 pages from a local website on a AWS EC2 m5.large instance.
+_chromedp requesting 933 real web pages over the network on a AWS EC2 m5.large instance.
-See [benchmark details](https://github.com/lightpanda-io/demo)._
+See [benchmark details](https://github.com/lightpanda-io/demo/blob/main/BENCHMARKS.md#crawler-benchmark)._
 
 Lightpanda is the open-source browser made for headless usage:
 
@@ -82,7 +82,7 @@ docker run -d --name lightpanda -p 9222:9222 lightpanda/browser:nightly
 ### Dump a URL
 
 ```console
-./lightpanda fetch --obey_robots --log_format pretty  --log_level info https://demo-browser.lightpanda.io/campfire-commerce/
+./lightpanda fetch --obey-robots --log-format pretty  --log-level info https://demo-browser.lightpanda.io/campfire-commerce/
 ```
 ```console
 INFO  telemetry : telemetry status . . . . . . . . . . . . .  [+0ms]
@@ -117,7 +117,7 @@ INFO  http : request complete . . . . . . . . . . . . . . . . [+141ms]
 ### Start a CDP server
 
 ```console
-./lightpanda serve --obey_robots --log_format pretty  --log_level info --host 127.0.0.1 --port 9222
+./lightpanda serve --obey-robots --log-format pretty  --log-level info --host 127.0.0.1 --port 9222
 ```
 ```console
 INFO  telemetry : telemetry status . . . . . . . . . . . . .  [+0ms]
@@ -186,7 +186,7 @@ Here are the key features we have implemented:
 - [x] Custom HTTP headers
 - [x] Proxy support
 - [x] Network interception
-- [x] Respect `robots.txt` with option `--obey_robots`
+- [x] Respect `robots.txt` with option `--obey-robots`
 
 NOTE: There are hundreds of Web APIs. Developing a browser (even just for headless mode) is a huge task. Coverage will increase over time.
 
@@ -317,7 +317,7 @@ First start the WPT's HTTP server from your `wpt/` clone dir.
 Run a Lightpanda browser
 
 ```
-zig build run -- --insecure_disable_tls_host_verification
+zig build run -- --insecure-disable-tls-host-verification
 ```
 
 Then you can start the wptrunner from the Demo's clone dir:

build.zig

@@ -17,24 +17,37 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const builtin = @import("builtin");
 
-const Build = std.Build;
+const lightpanda_version = std.SemanticVersion.parse(@import("build.zig.zon").version) catch unreachable;
+const min_zig_version = std.SemanticVersion.parse(@import("build.zig.zon").minimum_zig_version) catch unreachable;
+
+const Build = blk: {
+    if (builtin.zig_version.order(min_zig_version) == .lt) {
+        const message = std.fmt.comptimePrint(
+            \\Zig version is too old:
+            \\  current Zig version: {f}
+            \\  minimum Zig version: {f}
+        , .{ builtin.zig_version, min_zig_version });
+        @compileError(message);
+    } else {
+        break :blk std.Build;
+    }
+};
 
 pub fn build(b: *Build) !void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    const manifest = Manifest.init(b);
-
-    const git_commit = b.option([]const u8, "git_commit", "Current git commit");
-    const git_version = b.option([]const u8, "git_version", "Current git version (from tag)");
     const prebuilt_v8_path = b.option([]const u8, "prebuilt_v8_path", "Path to prebuilt libc_v8.a");
     const snapshot_path = b.option([]const u8, "snapshot_path", "Path to v8 snapshot");
 
+    const version = resolveVersion(b);
+    var stdout = std.fs.File.stdout().writer(&.{});
+    try stdout.interface.print("Lightpanda {f}\n", .{version});
+
     var opts = b.addOptions();
-    opts.addOption([]const u8, "version", manifest.version);
+    opts.addOption([]const u8, "version", b.fmt("{f}", .{version}));
-    opts.addOption([]const u8, "git_commit", git_commit orelse "dev");
-    opts.addOption(?[]const u8, "git_version", git_version orelse null);
     opts.addOption(?[]const u8, "snapshot_path", snapshot_path);
 
     const enable_tsan = b.option(bool, "tsan", "Enable Thread Sanitizer") orelse false;
@@ -96,6 +109,11 @@ pub fn build(b: *Build) !void {
         }
         const run_step = b.step("run", "Run the app");
         run_step.dependOn(&run_cmd.step);
+
+        const version_info_step = b.step("version", "Print the resolved version information");
+        const version_info_run = b.addRunArtifact(exe);
+        version_info_run.addArg("version");
+        version_info_step.dependOn(&version_info_run.step);
     }
 
     {
@@ -701,27 +719,41 @@ fn buildCurl(
     return lib;
 }
 
-const Manifest = struct {
+/// Returns `MAJOR.MINOR.PATCH-dev` when `git describe` fails.
-    version: []const u8,
+fn resolveVersion(b: *std.Build) std.SemanticVersion {
-    minimum_zig_version: []const u8,
+    const version_string = b.option([]const u8, "version_string", "Override the version of this build");
-
+    if (version_string) |semver_string| {
-    fn init(b: *std.Build) Manifest {
+        return std.SemanticVersion.parse(semver_string) catch |err| {
-        const input = @embedFile("build.zig.zon");
+            std.debug.panic("Expected -Dversion-string={s} to be a semantic version: {}", .{ semver_string, err });
-
-        var diagnostics: std.zon.parse.Diagnostics = .{};
-        defer diagnostics.deinit(b.allocator);
-
-        return std.zon.parse.fromSlice(Manifest, b.allocator, input, &diagnostics, .{
-            .free_on_error = true,
-            .ignore_unknown_fields = true,
-        }) catch |err| {
-            switch (err) {
-                error.OutOfMemory => @panic("OOM"),
-                error.ParseZon => {
-                    std.debug.print("Parse diagnostics:\n{f}\n", .{diagnostics});
-                    std.process.exit(1);
-                },
-            }
         };
     }
-};
+
+    // If it's a stable release (no pre or build metadata in build.zig.zon), use it as is
+    if (lightpanda_version.pre == null and lightpanda_version.build == null) return lightpanda_version;
+
+    // For dev/nightly versions, calculate the commit count and hash
+    const git_hash_raw = runGit(b, &.{ "rev-parse", "--short", "HEAD" }) catch return lightpanda_version;
+    const commit_hash = std.mem.trim(u8, git_hash_raw, " \n\r");
+
+    const git_count_raw = runGit(b, &.{ "rev-list", "--count", "HEAD" }) catch return lightpanda_version;
+    const commit_count = std.mem.trim(u8, git_count_raw, " \n\r");
+
+    return .{
+        .major = lightpanda_version.major,
+        .minor = lightpanda_version.minor,
+        .patch = lightpanda_version.patch,
+        .pre = b.fmt("{s}.{s}", .{ lightpanda_version.pre.?, commit_count }),
+        .build = commit_hash,
+    };
+}
+
+/// Helper function to run git commands and return stdout
+fn runGit(b: *std.Build, args: []const []const u8) ![]const u8 {
+    var code: u8 = undefined;
+    const dir = b.pathFromRoot(".");
+    var command: std.ArrayList([]const u8) = .empty;
+    defer command.deinit(b.allocator);
+    try command.appendSlice(b.allocator, &.{ "git", "-C", dir });
+    try command.appendSlice(b.allocator, args);
+    return b.runAllowFail(command.items, &code, .Ignore);
+}

build.zig.zon

@@ -1,6 +1,6 @@
 .{
     .name = .browser,
-    .version = "0.0.0",
+    .version = "1.0.0-dev",
     .fingerprint = 0xda130f3af836cea0, // Changing this has security and trust implications.
     .minimum_zig_version = "0.15.2",
     .dependencies = .{

src/ArenaPool.zig

@@ -17,12 +17,15 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
+const builtin = @import("builtin");
 
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
 
 const ArenaPool = @This();
 
+const IS_DEBUG = builtin.mode == .Debug;
+
 allocator: Allocator,
 retain_bytes: usize,
 free_list_len: u16 = 0,
@@ -30,10 +33,17 @@ free_list: ?*Entry = null,
 free_list_max: u16,
 entry_pool: std.heap.MemoryPool(Entry),
 mutex: std.Thread.Mutex = .{},
+// Debug mode: track acquire/release counts per debug name to detect leaks and double-frees
+_leak_track: if (IS_DEBUG) std.StringHashMapUnmanaged(isize) else void = if (IS_DEBUG) .empty else {},
 
 const Entry = struct {
     next: ?*Entry,
     arena: ArenaAllocator,
+    debug: if (IS_DEBUG) []const u8 else void = if (IS_DEBUG) "" else {},
+};
+
+pub const DebugInfo = struct {
+    debug: []const u8 = "",
 };
 
 pub fn init(allocator: Allocator, free_list_max: u16, retain_bytes: usize) ArenaPool {
@@ -42,10 +52,26 @@ pub fn init(allocator: Allocator, free_list_max: u16, retain_bytes: usize) Arena
         .free_list_max = free_list_max,
         .retain_bytes = retain_bytes,
         .entry_pool = .init(allocator),
+        ._leak_track = if (IS_DEBUG) .empty else {},
     };
 }
 
 pub fn deinit(self: *ArenaPool) void {
+    if (IS_DEBUG) {
+        var has_leaks = false;
+        var it = self._leak_track.iterator();
+        while (it.next()) |kv| {
+            if (kv.value_ptr.* != 0) {
+                std.debug.print("ArenaPool leak detected: '{s}' count={d}\n", .{ kv.key_ptr.*, kv.value_ptr.* });
+                has_leaks = true;
+            }
+        }
+        if (has_leaks) {
+            @panic("ArenaPool: leaked arenas detected");
+        }
+        self._leak_track.deinit(self.allocator);
+    }
+
     var entry = self.free_list;
     while (entry) |e| {
         entry = e.next;
@@ -54,13 +80,21 @@ pub fn deinit(self: *ArenaPool) void {
     self.entry_pool.deinit();
 }
 
-pub fn acquire(self: *ArenaPool) !Allocator {
+pub fn acquire(self: *ArenaPool, dbg: DebugInfo) !Allocator {
     self.mutex.lock();
     defer self.mutex.unlock();
 
     if (self.free_list) |entry| {
         self.free_list = entry.next;
         self.free_list_len -= 1;
+        if (IS_DEBUG) {
+            entry.debug = dbg.debug;
+            const gop = try self._leak_track.getOrPut(self.allocator, dbg.debug);
+            if (!gop.found_existing) {
+                gop.value_ptr.* = 0;
+            }
+            gop.value_ptr.* += 1;
+        }
         return entry.arena.allocator();
     }
 
@@ -68,8 +102,16 @@ pub fn acquire(self: *ArenaPool) !Allocator {
     entry.* = .{
         .next = null,
         .arena = ArenaAllocator.init(self.allocator),
+        .debug = if (IS_DEBUG) dbg.debug else {},
     };
 
+    if (IS_DEBUG) {
+        const gop = try self._leak_track.getOrPut(self.allocator, dbg.debug);
+        if (!gop.found_existing) {
+            gop.value_ptr.* = 0;
+        }
+        gop.value_ptr.* += 1;
+    }
     return entry.arena.allocator();
 }
 
@@ -83,6 +125,19 @@ pub fn release(self: *ArenaPool, allocator: Allocator) void {
     self.mutex.lock();
     defer self.mutex.unlock();
 
+    if (IS_DEBUG) {
+        if (self._leak_track.getPtr(entry.debug)) |count| {
+            count.* -= 1;
+            if (count.* < 0) {
+                std.debug.print("ArenaPool double-free detected: '{s}'\n", .{entry.debug});
+                @panic("ArenaPool: double-free detected");
+            }
+        } else {
+            std.debug.print("ArenaPool release of untracked arena: '{s}'\n", .{entry.debug});
+            @panic("ArenaPool: release of untracked arena");
+        }
+    }
+
     const free_list_len = self.free_list_len;
     if (free_list_len == self.free_list_max) {
         arena.deinit();
@@ -100,13 +155,18 @@ pub fn reset(_: *const ArenaPool, allocator: Allocator, retain: usize) void {
     _ = arena.reset(.{ .retain_with_limit = retain });
 }
 
+pub fn resetRetain(_: *const ArenaPool, allocator: Allocator) void {
+    const arena: *std.heap.ArenaAllocator = @ptrCast(@alignCast(allocator.ptr));
+    _ = arena.reset(.retain_capacity);
+}
+
 const testing = std.testing;
 
 test "arena pool - basic acquire and use" {
     var pool = ArenaPool.init(testing.allocator, 512, 1024 * 16);
     defer pool.deinit();
 
-    const alloc = try pool.acquire();
+    const alloc = try pool.acquire(.{ .debug = "test" });
     const buf = try alloc.alloc(u8, 64);
     @memset(buf, 0xAB);
     try testing.expectEqual(@as(u8, 0xAB), buf[0]);
@@ -118,14 +178,14 @@ test "arena pool - reuse entry after release" {
     var pool = ArenaPool.init(testing.allocator, 512, 1024 * 16);
     defer pool.deinit();
 
-    const alloc1 = try pool.acquire();
+    const alloc1 = try pool.acquire(.{ .debug = "test" });
     try testing.expectEqual(@as(u16, 0), pool.free_list_len);
 
     pool.release(alloc1);
     try testing.expectEqual(@as(u16, 1), pool.free_list_len);
 
     // The same entry should be returned from the free list.
-    const alloc2 = try pool.acquire();
+    const alloc2 = try pool.acquire(.{ .debug = "test" });
     try testing.expectEqual(@as(u16, 0), pool.free_list_len);
     try testing.expectEqual(alloc1.ptr, alloc2.ptr);
 
@@ -136,9 +196,9 @@ test "arena pool - multiple concurrent arenas" {
     var pool = ArenaPool.init(testing.allocator, 512, 1024 * 16);
     defer pool.deinit();
 
-    const a1 = try pool.acquire();
+    const a1 = try pool.acquire(.{ .debug = "test1" });
-    const a2 = try pool.acquire();
+    const a2 = try pool.acquire(.{ .debug = "test2" });
-    const a3 = try pool.acquire();
+    const a3 = try pool.acquire(.{ .debug = "test3" });
 
     // All three must be distinct arenas.
     try testing.expect(a1.ptr != a2.ptr);
@@ -161,8 +221,8 @@ test "arena pool - free list respects max limit" {
     var pool = ArenaPool.init(testing.allocator, 1, 1024 * 16);
     defer pool.deinit();
 
-    const a1 = try pool.acquire();
+    const a1 = try pool.acquire(.{ .debug = "test1" });
-    const a2 = try pool.acquire();
+    const a2 = try pool.acquire(.{ .debug = "test2" });
 
     pool.release(a1);
     try testing.expectEqual(@as(u16, 1), pool.free_list_len);
@@ -176,7 +236,7 @@ test "arena pool - reset clears memory without releasing" {
     var pool = ArenaPool.init(testing.allocator, 512, 1024 * 16);
     defer pool.deinit();
 
-    const alloc = try pool.acquire();
+    const alloc = try pool.acquire(.{ .debug = "test" });
 
     const buf = try alloc.alloc(u8, 128);
     @memset(buf, 0xFF);
@@ -200,8 +260,8 @@ test "arena pool - deinit with entries in free list" {
     // detected by the test allocator).
     var pool = ArenaPool.init(testing.allocator, 512, 1024 * 16);
 
-    const a1 = try pool.acquire();
+    const a1 = try pool.acquire(.{ .debug = "test1" });
-    const a2 = try pool.acquire();
+    const a2 = try pool.acquire(.{ .debug = "test2" });
     _ = try a1.alloc(u8, 256);
     _ = try a2.alloc(u8, 512);
     pool.release(a1);

src/Config.zig

@@ -163,6 +163,20 @@ pub fn cdpTimeout(self: *const Config) usize {
     };
 }
 
+pub fn port(self: *const Config) u16 {
+    return switch (self.mode) {
+        .serve => |opts| opts.port,
+        else => unreachable,
+    };
+}
+
+pub fn advertiseHost(self: *const Config) []const u8 {
+    return switch (self.mode) {
+        .serve => |opts| opts.advertise_host orelse opts.host,
+        else => unreachable,
+    };
+}
+
 pub fn webBotAuth(self: *const Config) ?WebBotAuthConfig {
     return switch (self.mode) {
         inline .serve, .fetch, .mcp => |opts| WebBotAuthConfig{
@@ -199,6 +213,7 @@ pub const Mode = union(RunMode) {
 pub const Serve = struct {
     host: []const u8 = "127.0.0.1",
     port: u16 = 9222,
+    advertise_host: ?[]const u8 = null,
     timeout: u31 = 10,
     cdp_max_connections: u16 = 16,
     cdp_max_pending_connections: u16 = 128,
@@ -217,6 +232,13 @@ pub const DumpFormat = enum {
     semantic_tree_text,
 };
 
+pub const WaitUntil = enum {
+    load,
+    domcontentloaded,
+    networkidle,
+    done,
+};
+
 pub const Fetch = struct {
     url: [:0]const u8,
     dump_mode: ?DumpFormat = null,
@@ -224,6 +246,8 @@ pub const Fetch = struct {
     with_base: bool = false,
     with_frames: bool = false,
     strip: dump.Opts.Strip = .{},
+    wait_ms: u32 = 5000,
+    wait_until: WaitUntil = .load,
 };
 
 pub const Common = struct {
@@ -293,71 +317,71 @@ pub fn printUsageAndExit(self: *const Config, success: bool) void {
     //                                                                     MAX_HELP_LEN|
     const common_options =
         \\
-        \\--insecure_disable_tls_host_verification
+        \\--insecure-disable-tls-host-verification
         \\                Disables host verification on all HTTP requests. This is an
         \\                advanced option which should only be set if you understand
         \\                and accept the risk of disabling host verification.
         \\
-        \\--obey_robots
+        \\--obey-robots
         \\                Fetches and obeys the robots.txt (if available) of the web pages
         \\                we make requests towards.
         \\                Defaults to false.
         \\
-        \\--http_proxy    The HTTP proxy to use for all HTTP requests.
+        \\--http-proxy    The HTTP proxy to use for all HTTP requests.
         \\                A username:password can be included for basic authentication.
         \\                Defaults to none.
         \\
-        \\--proxy_bearer_token
+        \\--proxy-bearer-token
         \\                The <token> to send for bearer authentication with the proxy
         \\                Proxy-Authorization: Bearer <token>
         \\
-        \\--http_max_concurrent
+        \\--http-max-concurrent
         \\                The maximum number of concurrent HTTP requests.
         \\                Defaults to 10.
         \\
-        \\--http_max_host_open
+        \\--http-max-host-open
         \\                The maximum number of open connection to a given host:port.
         \\                Defaults to 4.
         \\
-        \\--http_connect_timeout
+        \\--http-connect-timeout
         \\                The time, in milliseconds, for establishing an HTTP connection
         \\                before timing out. 0 means it never times out.
         \\                Defaults to 0.
         \\
-        \\--http_timeout
+        \\--http-timeout
         \\                The maximum time, in milliseconds, the transfer is allowed
         \\                to complete. 0 means it never times out.
         \\                Defaults to 10000.
         \\
-        \\--http_max_response_size
+        \\--http-max-response-size
         \\                Limits the acceptable response size for any request
         \\                (e.g. XHR, fetch, script loading, ...).
         \\                Defaults to no limit.
         \\
-        \\--log_level     The log level: debug, info, warn, error or fatal.
+        \\--log-level     The log level: debug, info, warn, error or fatal.
         \\                Defaults to
     ++ (if (builtin.mode == .Debug) " info." else "warn.") ++
         \\
         \\
-        \\--log_format    The log format: pretty or logfmt.
+        \\--log-format    The log format: pretty or logfmt.
         \\                Defaults to
     ++ (if (builtin.mode == .Debug) " pretty." else " logfmt.") ++
         \\
         \\
-        \\--log_filter_scopes
+        \\--log-filter-scopes
         \\                Filter out too verbose logs per scope:
         \\                http, unknown_prop, event, ...
         \\
-        \\--user_agent_suffix
+        \\--user-agent-suffix
         \\                Suffix to append to the Lightpanda/X.Y User-Agent
         \\
-        \\--web_bot_auth_key_file
+        \\--web-bot-auth-key-file
         \\                Path to the Ed25519 private key PEM file.
         \\
-        \\--web_bot_auth_keyid
+        \\--web-bot-auth-keyid
         \\                The JWK thumbprint of your public key.
         \\
-        \\--web_bot_auth_domain
+        \\--web-bot-auth-domain
         \\                Your domain e.g. yourdomain.com
     ;
 
@@ -376,16 +400,23 @@ pub fn printUsageAndExit(self: *const Config, success: bool) void {
         \\                Argument must be 'html', 'markdown', 'semantic_tree', or 'semantic_tree_text'.
         \\                Defaults to no dump.
         \\
-        \\--strip_mode    Comma separated list of tag groups to remove from dump
+        \\--strip-mode    Comma separated list of tag groups to remove from dump
-        \\                the dump. e.g. --strip_mode js,css
+        \\                the dump. e.g. --strip-mode js,css
         \\                  - "js" script and link[as=script, rel=preload]
         \\                  - "ui" includes img, picture, video, css and svg
         \\                  - "css" includes style and link[rel=stylesheet]
         \\                  - "full" includes js, ui and css
         \\
-        \\--with_base     Add a <base> tag in dump. Defaults to false.
+        \\--with-base     Add a <base> tag in dump. Defaults to false.
         \\
-        \\--with_frames   Includes the contents of iframes. Defaults to false.
+        \\--with-frames   Includes the contents of iframes. Defaults to false.
+        \\
+        \\--wait-ms       Wait time in milliseconds.
+        \\                Defaults to 5000.
+        \\
+        \\--wait-until    Wait until the specified event.
+        \\                Supported events: load, domcontentloaded, networkidle, done.
+        \\                Defaults to 'done'.
         \\
     ++ common_options ++
         \\
@@ -400,14 +431,19 @@ pub fn printUsageAndExit(self: *const Config, success: bool) void {
         \\--port          Port of the CDP server
         \\                Defaults to 9222
         \\
+        \\--advertise-host
+        \\                The host to advertise, e.g. in the /json/version response.
+        \\                Useful, for example, when --host is 0.0.0.0.
+        \\                Defaults to --host value
+        \\
         \\--timeout       Inactivity timeout in seconds before disconnecting clients
         \\                Defaults to 10 (seconds). Limited to 604800 (1 week).
         \\
-        \\--cdp_max_connections
+        \\--cdp-max-connections
         \\                Maximum number of simultaneous CDP connections.
         \\                Defaults to 16.
         \\
-        \\--cdp_max_pending_connections
+        \\--cdp-max-pending-connections
         \\                Maximum pending connections in the accept queue.
         \\                Defaults to 128.
         \\
@@ -485,15 +521,15 @@ fn inferMode(opt: []const u8) ?RunMode {
         return .fetch;
     }
 
-    if (std.mem.eql(u8, opt, "--strip_mode")) {
+    if (std.mem.eql(u8, opt, "--strip-mode") or std.mem.eql(u8, opt, "--strip_mode")) {
         return .fetch;
     }
 
-    if (std.mem.eql(u8, opt, "--with_base")) {
+    if (std.mem.eql(u8, opt, "--with-base") or std.mem.eql(u8, opt, "--with_base")) {
         return .fetch;
     }
 
-    if (std.mem.eql(u8, opt, "--with_frames")) {
+    if (std.mem.eql(u8, opt, "--with-frames") or std.mem.eql(u8, opt, "--with_frames")) {
         return .fetch;
     }
 
@@ -541,6 +577,15 @@ fn parseServeArgs(
             continue;
         }
 
+        if (std.mem.eql(u8, "--advertise-host", opt) or std.mem.eql(u8, "--advertise_host", opt)) {
+            const str = args.next() orelse {
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
+                return error.InvalidArgument;
+            };
+            serve.advertise_host = try allocator.dupe(u8, str);
+            continue;
+        }
+
         if (std.mem.eql(u8, "--timeout", opt)) {
             const str = args.next() orelse {
                 log.fatal(.app, "missing argument value", .{ .arg = "--timeout" });
@@ -554,27 +599,27 @@ fn parseServeArgs(
             continue;
         }
 
-        if (std.mem.eql(u8, "--cdp_max_connections", opt)) {
+        if (std.mem.eql(u8, "--cdp-max-connections", opt) or std.mem.eql(u8, "--cdp_max_connections", opt)) {
             const str = args.next() orelse {
-                log.fatal(.app, "missing argument value", .{ .arg = "--cdp_max_connections" });
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
                 return error.InvalidArgument;
             };
 
             serve.cdp_max_connections = std.fmt.parseInt(u16, str, 10) catch |err| {
-                log.fatal(.app, "invalid argument value", .{ .arg = "--cdp_max_connections", .err = err });
+                log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
                 return error.InvalidArgument;
             };
             continue;
         }
 
-        if (std.mem.eql(u8, "--cdp_max_pending_connections", opt)) {
+        if (std.mem.eql(u8, "--cdp-max-pending-connections", opt) or std.mem.eql(u8, "--cdp_max_pending_connections", opt)) {
             const str = args.next() orelse {
-                log.fatal(.app, "missing argument value", .{ .arg = "--cdp_max_pending_connections" });
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
                 return error.InvalidArgument;
             };
 
             serve.cdp_max_pending_connections = std.fmt.parseInt(u16, str, 10) catch |err| {
-                log.fatal(.app, "invalid argument value", .{ .arg = "--cdp_max_pending_connections", .err = err });
+                log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
                 return error.InvalidArgument;
             };
             continue;
@@ -619,8 +664,34 @@ fn parseFetchArgs(
     var url: ?[:0]const u8 = null;
     var common: Common = .{};
     var strip: dump.Opts.Strip = .{};
+    var wait_ms: u32 = 5000;
+    var wait_until: WaitUntil = .load;
 
     while (args.next()) |opt| {
+        if (std.mem.eql(u8, "--wait-ms", opt) or std.mem.eql(u8, "--wait_ms", opt)) {
+            const str = args.next() orelse {
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
+                return error.InvalidArgument;
+            };
+            wait_ms = std.fmt.parseInt(u32, str, 10) catch |err| {
+                log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
+                return error.InvalidArgument;
+            };
+            continue;
+        }
+
+        if (std.mem.eql(u8, "--wait-until", opt) or std.mem.eql(u8, "--wait_until", opt)) {
+            const str = args.next() orelse {
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
+                return error.InvalidArgument;
+            };
+            wait_until = std.meta.stringToEnum(WaitUntil, str) orelse {
+                log.fatal(.app, "invalid argument value", .{ .arg = opt, .val = str });
+                return error.InvalidArgument;
+            };
+            continue;
+        }
+
         if (std.mem.eql(u8, "--dump", opt)) {
             var peek_args = args.*;
             if (peek_args.next()) |next_arg| {
@@ -639,25 +710,25 @@ fn parseFetchArgs(
         if (std.mem.eql(u8, "--noscript", opt)) {
             log.warn(.app, "deprecation warning", .{
                 .feature = "--noscript argument",
-                .hint = "use '--strip_mode js' instead",
+                .hint = "use '--strip-mode js' instead",
             });
             strip.js = true;
             continue;
         }
 
-        if (std.mem.eql(u8, "--with_base", opt)) {
+        if (std.mem.eql(u8, "--with-base", opt) or std.mem.eql(u8, "--with_base", opt)) {
             with_base = true;
             continue;
         }
 
-        if (std.mem.eql(u8, "--with_frames", opt)) {
+        if (std.mem.eql(u8, "--with-frames", opt) or std.mem.eql(u8, "--with_frames", opt)) {
             with_frames = true;
             continue;
         }
 
-        if (std.mem.eql(u8, "--strip_mode", opt)) {
+        if (std.mem.eql(u8, "--strip-mode", opt) or std.mem.eql(u8, "--strip_mode", opt)) {
             const str = args.next() orelse {
-                log.fatal(.app, "missing argument value", .{ .arg = "--strip_mode" });
+                log.fatal(.app, "missing argument value", .{ .arg = opt });
                 return error.InvalidArgument;
             };
 
@@ -675,7 +746,7 @@ fn parseFetchArgs(
                     strip.ui = true;
                     strip.css = true;
                 } else {
-                    log.fatal(.app, "invalid option choice", .{ .arg = "--strip_mode", .value = trimmed });
+                    log.fatal(.app, "invalid option choice", .{ .arg = opt, .value = trimmed });
                 }
             }
             continue;
@@ -709,6 +780,8 @@ fn parseFetchArgs(
         .common = common,
         .with_base = with_base,
         .with_frames = with_frames,
+        .wait_ms = wait_ms,
+        .wait_until = wait_until,
     };
 }
 
@@ -718,102 +791,102 @@ fn parseCommonArg(
     args: *std.process.ArgIterator,
     common: *Common,
 ) !bool {
-    if (std.mem.eql(u8, "--insecure_disable_tls_host_verification", opt)) {
+    if (std.mem.eql(u8, "--insecure-disable-tls-host-verification", opt) or std.mem.eql(u8, "--insecure_disable_tls_host_verification", opt)) {
         common.tls_verify_host = false;
         return true;
     }
 
-    if (std.mem.eql(u8, "--obey_robots", opt)) {
+    if (std.mem.eql(u8, "--obey-robots", opt) or std.mem.eql(u8, "--obey_robots", opt)) {
         common.obey_robots = true;
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_proxy", opt)) {
+    if (std.mem.eql(u8, "--http-proxy", opt) or std.mem.eql(u8, "--http_proxy", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_proxy" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         common.http_proxy = try allocator.dupeZ(u8, str);
         return true;
     }
 
-    if (std.mem.eql(u8, "--proxy_bearer_token", opt)) {
+    if (std.mem.eql(u8, "--proxy-bearer-token", opt) or std.mem.eql(u8, "--proxy_bearer_token", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--proxy_bearer_token" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         common.proxy_bearer_token = try allocator.dupeZ(u8, str);
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_max_concurrent", opt)) {
+    if (std.mem.eql(u8, "--http-max-concurrent", opt) or std.mem.eql(u8, "--http_max_concurrent", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_max_concurrent" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.http_max_concurrent = std.fmt.parseInt(u8, str, 10) catch |err| {
-            log.fatal(.app, "invalid argument value", .{ .arg = "--http_max_concurrent", .err = err });
+            log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_max_host_open", opt)) {
+    if (std.mem.eql(u8, "--http-max-host-open", opt) or std.mem.eql(u8, "--http_max_host_open", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_max_host_open" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.http_max_host_open = std.fmt.parseInt(u8, str, 10) catch |err| {
-            log.fatal(.app, "invalid argument value", .{ .arg = "--http_max_host_open", .err = err });
+            log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_connect_timeout", opt)) {
+    if (std.mem.eql(u8, "--http-connect-timeout", opt) or std.mem.eql(u8, "--http_connect_timeout", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_connect_timeout" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.http_connect_timeout = std.fmt.parseInt(u31, str, 10) catch |err| {
-            log.fatal(.app, "invalid argument value", .{ .arg = "--http_connect_timeout", .err = err });
+            log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_timeout", opt)) {
+    if (std.mem.eql(u8, "--http-timeout", opt) or std.mem.eql(u8, "--http_timeout", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_timeout" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.http_timeout = std.fmt.parseInt(u31, str, 10) catch |err| {
-            log.fatal(.app, "invalid argument value", .{ .arg = "--http_timeout", .err = err });
+            log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--http_max_response_size", opt)) {
+    if (std.mem.eql(u8, "--http-max-response-size", opt) or std.mem.eql(u8, "--http_max_response_size", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--http_max_response_size" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.http_max_response_size = std.fmt.parseInt(usize, str, 10) catch |err| {
-            log.fatal(.app, "invalid argument value", .{ .arg = "--http_max_response_size", .err = err });
+            log.fatal(.app, "invalid argument value", .{ .arg = opt, .err = err });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--log_level", opt)) {
+    if (std.mem.eql(u8, "--log-level", opt) or std.mem.eql(u8, "--log_level", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--log_level" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
@@ -821,26 +894,26 @@ fn parseCommonArg(
             if (std.mem.eql(u8, str, "error")) {
                 break :blk .err;
             }
-            log.fatal(.app, "invalid option choice", .{ .arg = "--log_level", .value = str });
+            log.fatal(.app, "invalid option choice", .{ .arg = opt, .value = str });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--log_format", opt)) {
+    if (std.mem.eql(u8, "--log-format", opt) or std.mem.eql(u8, "--log_format", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--log_format" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
 
         common.log_format = std.meta.stringToEnum(log.Format, str) orelse {
-            log.fatal(.app, "invalid option choice", .{ .arg = "--log_format", .value = str });
+            log.fatal(.app, "invalid option choice", .{ .arg = opt, .value = str });
             return error.InvalidArgument;
         };
         return true;
     }
 
-    if (std.mem.eql(u8, "--log_filter_scopes", opt)) {
+    if (std.mem.eql(u8, "--log-filter-scopes", opt) or std.mem.eql(u8, "--log_filter_scopes", opt)) {
         if (builtin.mode != .Debug) {
             log.fatal(.app, "experimental", .{ .help = "log scope filtering is only available in debug builds" });
             return false;
@@ -857,7 +930,7 @@ fn parseCommonArg(
         var it = std.mem.splitScalar(u8, str, ',');
         while (it.next()) |part| {
             try arr.append(allocator, std.meta.stringToEnum(log.Scope, part) orelse {
-                log.fatal(.app, "invalid option choice", .{ .arg = "--log_filter_scopes", .value = part });
+                log.fatal(.app, "invalid option choice", .{ .arg = opt, .value = part });
                 return false;
             });
         }
@@ -865,14 +938,14 @@ fn parseCommonArg(
         return true;
     }
 
-    if (std.mem.eql(u8, "--user_agent_suffix", opt)) {
+    if (std.mem.eql(u8, "--user-agent-suffix", opt) or std.mem.eql(u8, "--user_agent_suffix", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--user_agent_suffix" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         for (str) |c| {
             if (!std.ascii.isPrint(c)) {
-                log.fatal(.app, "not printable character", .{ .arg = "--user_agent_suffix" });
+                log.fatal(.app, "not printable character", .{ .arg = opt });
                 return error.InvalidArgument;
             }
         }
@@ -880,27 +953,27 @@ fn parseCommonArg(
         return true;
     }
 
-    if (std.mem.eql(u8, "--web_bot_auth_key_file", opt)) {
+    if (std.mem.eql(u8, "--web-bot-auth-key-file", opt) or std.mem.eql(u8, "--web_bot_auth_key_file", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--web_bot_auth_key_file" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         common.web_bot_auth_key_file = try allocator.dupe(u8, str);
         return true;
     }
 
-    if (std.mem.eql(u8, "--web_bot_auth_keyid", opt)) {
+    if (std.mem.eql(u8, "--web-bot-auth-keyid", opt) or std.mem.eql(u8, "--web_bot_auth_keyid", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--web_bot_auth_keyid" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         common.web_bot_auth_keyid = try allocator.dupe(u8, str);
         return true;
     }
 
-    if (std.mem.eql(u8, "--web_bot_auth_domain", opt)) {
+    if (std.mem.eql(u8, "--web-bot-auth-domain", opt) or std.mem.eql(u8, "--web_bot_auth_domain", opt)) {
         const str = args.next() orelse {
-            log.fatal(.app, "missing argument value", .{ .arg = "--web_bot_auth_domain" });
+            log.fatal(.app, "missing argument value", .{ .arg = opt });
             return error.InvalidArgument;
         };
         common.web_bot_auth_domain = try allocator.dupe(u8, str);

src/SemanticTree.zig

@@ -47,7 +47,15 @@ pub fn jsonStringify(self: @This(), jw: *std.json.Stringify) error{WriteFailed}!
         log.err(.app, "listener map failed", .{ .err = err });
         return error.WriteFailed;
     };
-    self.walk(self.dom_node, &xpath_buffer, null, &visitor, 1, listener_targets, 0) catch |err| {
+    var visibility_cache: Element.VisibilityCache = .empty;
+    var pointer_events_cache: Element.PointerEventsCache = .empty;
+    var ctx: WalkContext = .{
+        .xpath_buffer = &xpath_buffer,
+        .listener_targets = listener_targets,
+        .visibility_cache = &visibility_cache,
+        .pointer_events_cache = &pointer_events_cache,
+    };
+    self.walk(&ctx, self.dom_node, null, &visitor, 1, 0) catch |err| {
         log.err(.app, "semantic tree json dump failed", .{ .err = err });
         return error.WriteFailed;
     };
@@ -60,7 +68,15 @@ pub fn textStringify(self: @This(), writer: *std.Io.Writer) error{WriteFailed}!v
         log.err(.app, "listener map failed", .{ .err = err });
         return error.WriteFailed;
     };
-    self.walk(self.dom_node, &xpath_buffer, null, &visitor, 1, listener_targets, 0) catch |err| {
+    var visibility_cache: Element.VisibilityCache = .empty;
+    var pointer_events_cache: Element.PointerEventsCache = .empty;
+    var ctx: WalkContext = .{
+        .xpath_buffer = &xpath_buffer,
+        .listener_targets = listener_targets,
+        .visibility_cache = &visibility_cache,
+        .pointer_events_cache = &pointer_events_cache,
+    };
+    self.walk(&ctx, self.dom_node, null, &visitor, 1, 0) catch |err| {
         log.err(.app, "semantic tree text dump failed", .{ .err = err });
         return error.WriteFailed;
     };
@@ -84,7 +100,22 @@ const NodeData = struct {
     node_name: []const u8,
 };
 
-fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_name: ?[]const u8, visitor: anytype, index: usize, listener_targets: interactive.ListenerTargetMap, current_depth: u32) !void {
+const WalkContext = struct {
+    xpath_buffer: *std.ArrayList(u8),
+    listener_targets: interactive.ListenerTargetMap,
+    visibility_cache: *Element.VisibilityCache,
+    pointer_events_cache: *Element.PointerEventsCache,
+};
+
+fn walk(
+    self: @This(),
+    ctx: *WalkContext,
+    node: *Node,
+    parent_name: ?[]const u8,
+    visitor: anytype,
+    index: usize,
+    current_depth: u32,
+) !void {
     if (current_depth > self.max_depth) return;
 
     // 1. Skip non-content nodes
@@ -96,7 +127,7 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
         if (tag == .datalist or tag == .option or tag == .optgroup) return;
 
         // Check visibility using the engine's checkVisibility which handles CSS display: none
-        if (!el.checkVisibility(self.page)) {
+        if (!el.checkVisibilityCached(ctx.visibility_cache, self.page)) {
             return;
         }
 
@@ -137,7 +168,7 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
         }
 
         if (el.is(Element.Html)) |html_el| {
-            if (interactive.classifyInteractivity(el, html_el, listener_targets) != null) {
+            if (interactive.classifyInteractivity(self.page, el, html_el, ctx.listener_targets, ctx.pointer_events_cache) != null) {
                 is_interactive = true;
             }
         }
@@ -145,9 +176,9 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
         node_name = "root";
     }
 
-    const initial_xpath_len = xpath_buffer.items.len;
+    const initial_xpath_len = ctx.xpath_buffer.items.len;
-    try appendXPathSegment(node, xpath_buffer.writer(self.arena), index);
+    try appendXPathSegment(node, ctx.xpath_buffer.writer(self.arena), index);
-    const xpath = xpath_buffer.items;
+    const xpath = ctx.xpath_buffer.items;
 
     var name = try axn.getName(self.page, self.arena);
 
@@ -165,18 +196,6 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
         name = null;
     }
 
-    var data = NodeData{
-        .id = cdp_node.id,
-        .axn = axn,
-        .role = role,
-        .name = name,
-        .value = value,
-        .options = options,
-        .xpath = xpath,
-        .is_interactive = is_interactive,
-        .node_name = node_name,
-    };
-
     var should_visit = true;
     if (self.interactive_only) {
         var keep = false;
@@ -208,6 +227,18 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
 
     var did_visit = false;
     var should_walk_children = true;
+    var data: NodeData = .{
+        .id = cdp_node.id,
+        .axn = axn,
+        .role = role,
+        .name = name,
+        .value = value,
+        .options = options,
+        .xpath = xpath,
+        .is_interactive = is_interactive,
+        .node_name = node_name,
+    };
+
     if (should_visit) {
         should_walk_children = try visitor.visit(node, &data);
         did_visit = true; // Always true if should_visit was true, because visit() executed and opened structures
@@ -233,7 +264,7 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
             }
             gop.value_ptr.* += 1;
 
-            try self.walk(child, xpath_buffer, name, visitor, gop.value_ptr.*, listener_targets, current_depth + 1);
+            try self.walk(ctx, child, name, visitor, gop.value_ptr.*, current_depth + 1);
         }
     }
 
@@ -241,11 +272,11 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
         try visitor.leave();
     }
 
-    xpath_buffer.shrinkRetainingCapacity(initial_xpath_len);
+    ctx.xpath_buffer.shrinkRetainingCapacity(initial_xpath_len);
 }
 
 fn extractSelectOptions(node: *Node, page: *Page, arena: std.mem.Allocator) ![]OptionData {
-    var options = std.ArrayListUnmanaged(OptionData){};
+    var options: std.ArrayList(OptionData) = .empty;
     var it = node.childrenIterator();
     while (it.next()) |child| {
         if (child.is(Element)) |el| {

src/Server.zig

@@ -45,7 +45,7 @@ clients_pool: std.heap.MemoryPool(Client),
 
 pub fn init(app: *App, address: net.Address) !*Server {
     const allocator = app.allocator;
-    const json_version_response = try buildJSONVersionResponse(allocator, address);
+    const json_version_response = try buildJSONVersionResponse(app);
     errdefer allocator.free(json_version_response);
 
     const self = try allocator.create(Server);
@@ -302,15 +302,8 @@ pub const Client = struct {
         var ms_remaining = self.ws.timeout_ms;
 
         while (true) {
-            switch (cdp.pageWait(ms_remaining)) {
+            const result = cdp.pageWait(ms_remaining) catch |wait_err| switch (wait_err) {
-                .cdp_socket => {
+                error.NoPage => {
-                    if (self.readSocket() == false) {
-                        return;
-                    }
-                    last_message = milliTimestamp(.monotonic);
-                    ms_remaining = self.ws.timeout_ms;
-                },
-                .no_page => {
                     const status = http.tick(ms_remaining) catch |err| {
                         log.err(.app, "http tick", .{ .err = err });
                         return;
@@ -324,6 +317,18 @@ pub const Client = struct {
                     }
                     last_message = milliTimestamp(.monotonic);
                     ms_remaining = self.ws.timeout_ms;
+                    continue;
+                },
+                else => return wait_err,
+            };
+
+            switch (result) {
+                .cdp_socket => {
+                    if (self.readSocket() == false) {
+                        return;
+                    }
+                    last_message = milliTimestamp(.monotonic);
+                    ms_remaining = self.ws.timeout_ms;
                 },
                 .done => {
                     const now = milliTimestamp(.monotonic);
@@ -484,11 +489,17 @@ pub const Client = struct {
 // --------
 
 fn buildJSONVersionResponse(
-    allocator: Allocator,
+    app: *const App,
-    address: net.Address,
 ) ![]const u8 {
-    const body_format = "{{\"webSocketDebuggerUrl\": \"ws://{f}/\"}}";
+    const port = app.config.port();
-    const body_len = std.fmt.count(body_format, .{address});
+    const host = app.config.advertiseHost();
+    if (std.mem.eql(u8, host, "0.0.0.0")) {
+        log.info(.cdp, "unreachable advertised host", .{
+            .message = "when --host is set to 0.0.0.0 consider setting --advertise-host to a reachable address",
+        });
+    }
+    const body_format = "{{\"webSocketDebuggerUrl\": \"ws://{s}:{d}/\"}}";
+    const body_len = std.fmt.count(body_format, .{ host, port });
 
     // We send a Connection: Close (and actually close the connection)
     // because chromedp (Go driver) sends a request to /json/version and then
@@ -502,23 +513,22 @@ fn buildJSONVersionResponse(
         "Connection: Close\r\n" ++
         "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++
         body_format;
-    return try std.fmt.allocPrint(allocator, response_format, .{ body_len, address });
+    return try std.fmt.allocPrint(app.allocator, response_format, .{ body_len, host, port });
 }
 
 pub const timestamp = @import("datetime.zig").timestamp;
 pub const milliTimestamp = @import("datetime.zig").milliTimestamp;
 
-const testing = std.testing;
+const testing = @import("testing.zig");
 test "server: buildJSONVersionResponse" {
-    const address = try net.Address.parseIp4("127.0.0.1", 9001);
+    const res = try buildJSONVersionResponse(testing.test_app);
-    const res = try buildJSONVersionResponse(testing.allocator, address);
+    defer testing.test_app.allocator.free(res);
-    defer testing.allocator.free(res);
 
-    try testing.expectEqualStrings("HTTP/1.1 200 OK\r\n" ++
+    try testing.expectEqual("HTTP/1.1 200 OK\r\n" ++
         "Content-Length: 48\r\n" ++
         "Connection: Close\r\n" ++
         "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++
-        "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9001/\"}", res);
+        "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9222/\"}", res);
 }
 
 test "Client: http invalid request" {
@@ -526,7 +536,7 @@ test "Client: http invalid request" {
     defer c.deinit();
 
     const res = try c.httpRequest("GET /over/9000 HTTP/1.1\r\n" ++ "Header: " ++ ("a" ** 4100) ++ "\r\n\r\n");
-    try testing.expectEqualStrings("HTTP/1.1 413 \r\n" ++
+    try testing.expectEqual("HTTP/1.1 413 \r\n" ++
         "Connection: Close\r\n" ++
         "Content-Length: 17\r\n\r\n" ++
         "Request too large", res);
@@ -595,7 +605,7 @@ test "Client: http valid handshake" {
         "Custom:  Header-Value\r\n\r\n";
 
     const res = try c.httpRequest(request);
-    try testing.expectEqualStrings("HTTP/1.1 101 Switching Protocols\r\n" ++
+    try testing.expectEqual("HTTP/1.1 101 Switching Protocols\r\n" ++
         "Upgrade: websocket\r\n" ++
         "Connection: upgrade\r\n" ++
         "Sec-Websocket-Accept: flzHu2DevQ2dSCSVqKSii5e9C2o=\r\n\r\n", res);
@@ -723,7 +733,7 @@ test "server: 404" {
     defer c.deinit();
 
     const res = try c.httpRequest("GET /unknown HTTP/1.1\r\n\r\n");
-    try testing.expectEqualStrings("HTTP/1.1 404 \r\n" ++
+    try testing.expectEqual("HTTP/1.1 404 \r\n" ++
         "Connection: Close\r\n" ++
         "Content-Length: 9\r\n\r\n" ++
         "Not found", res);
@@ -735,7 +745,7 @@ test "server: get /json/version" {
         "Content-Length: 48\r\n" ++
         "Connection: Close\r\n" ++
         "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++
-        "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9583/\"}";
+        "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9222/\"}";
 
     {
         // twice on the same connection
@@ -743,7 +753,7 @@ test "server: get /json/version" {
         defer c.deinit();
 
         const res1 = try c.httpRequest("GET /json/version HTTP/1.1\r\n\r\n");
-        try testing.expectEqualStrings(expected_response, res1);
+        try testing.expectEqual(expected_response, res1);
     }
 
     {
@@ -752,7 +762,7 @@ test "server: get /json/version" {
         defer c.deinit();
 
         const res1 = try c.httpRequest("GET /json/version HTTP/1.1\r\n\r\n");
-        try testing.expectEqualStrings(expected_response, res1);
+        try testing.expectEqual(expected_response, res1);
     }
 }
 
@@ -770,7 +780,7 @@ fn assertHTTPError(
         .{ expected_status, expected_body.len, expected_body },
     );
 
-    try testing.expectEqualStrings(expected_response, res);
+    try testing.expectEqual(expected_response, res);
 }
 
 fn assertWebSocketError(close_code: u16, input: []const u8) !void {
@@ -914,7 +924,7 @@ const TestClient = struct {
             "Custom:  Header-Value\r\n\r\n";
 
         const res = try self.httpRequest(request);
-        try testing.expectEqualStrings("HTTP/1.1 101 Switching Protocols\r\n" ++
+        try testing.expectEqual("HTTP/1.1 101 Switching Protocols\r\n" ++
             "Upgrade: websocket\r\n" ++
             "Connection: upgrade\r\n" ++
             "Sec-Websocket-Accept: flzHu2DevQ2dSCSVqKSii5e9C2o=\r\n\r\n", res);

src/browser/HttpClient.zig

@@ -848,14 +848,28 @@ fn processMessages(self: *Client) !bool {
             }
         }
 
+        // When the server sends "Connection: close" and closes the TLS
+        // connection without a close_notify alert, BoringSSL reports
+        // RecvError. If we already received valid HTTP headers, this is
+        // a normal end-of-body (the connection closure signals the end
+        // of the response per HTTP/1.1 when there is no Content-Length).
+        // We must check this before endTransfer, which may reset the
+        // easy handle.
+        const is_conn_close_recv = blk: {
+            const err = msg.err orelse break :blk false;
+            if (err != error.RecvError) break :blk false;
+            const hdr = msg.conn.getResponseHeader("connection", 0) orelse break :blk false;
+            break :blk std.ascii.eqlIgnoreCase(hdr.value, "close");
+        };
+
         // release it ASAP so that it's available; some done_callbacks
         // will load more resources.
         self.endTransfer(transfer);
 
         defer transfer.deinit();
 
-        if (msg.err) |err| {
+        if (msg.err != null and !is_conn_close_recv) {
-            requestFailed(transfer, err, true);
+            requestFailed(transfer, msg.err.?, true);
         } else blk: {
             // make sure the transfer can't be immediately aborted from a callback
             // since we still need it here.

src/browser/Mime.zig

@@ -386,6 +386,14 @@ pub fn isHTML(self: *const Mime) bool {
     return self.content_type == .text_html;
 }
 
+pub fn isText(mime: *const Mime) bool {
+    return switch (mime.content_type) {
+        .text_xml, .text_html, .text_javascript, .text_plain, .text_css => true,
+        .application_json => true,
+        else => false,
+    };
+}
+
 // we expect value to be lowercase
 fn parseContentType(value: []const u8) !struct { ContentType, usize } {
     const end = std.mem.indexOfScalarPos(u8, value, 0, ';') orelse value.len;

src/browser/Page.zig

@@ -35,6 +35,7 @@ const Factory = @import("Factory.zig");
 const Session = @import("Session.zig");
 const EventManager = @import("EventManager.zig");
 const ScriptManager = @import("ScriptManager.zig");
+const StyleManager = @import("StyleManager.zig");
 
 const Parser = @import("parser/Parser.zig");
 
@@ -60,6 +61,7 @@ const IntersectionObserver = @import("webapi/IntersectionObserver.zig");
 const CustomElementDefinition = @import("webapi/CustomElementDefinition.zig");
 const storage = @import("webapi/storage/storage.zig");
 const PageTransitionEvent = @import("webapi/event/PageTransitionEvent.zig");
+const SubmitEvent = @import("webapi/event/SubmitEvent.zig");
 const NavigationKind = @import("webapi/navigation/root.zig").NavigationKind;
 const KeyboardEvent = @import("webapi/event/KeyboardEvent.zig");
 const MouseEvent = @import("webapi/event/MouseEvent.zig");
@@ -144,6 +146,7 @@ _blob_urls: std.StringHashMapUnmanaged(*Blob) = .{},
 /// A call to `documentIsComplete` (which calls `_documentIsComplete`) resets it.
 _to_load: std.ArrayList(*Element.Html) = .{},
 
+_style_manager: StyleManager,
 _script_manager: ScriptManager,
 
 // List of active live ranges (for mutation updates per DOM spec)
@@ -269,6 +272,7 @@ pub fn init(self: *Page, frame_id: u32, session: *Session, parent: ?*Page) !void
         ._factory = factory,
         ._pending_loads = 1, // always 1 for the ScriptManager
         ._type = if (parent == null) .root else .frame,
+        ._style_manager = undefined,
         ._script_manager = undefined,
         ._event_manager = EventManager.init(session.page_arena, self),
     };
@@ -298,11 +302,18 @@ pub fn init(self: *Page, frame_id: u32, session: *Session, parent: ?*Page) !void
         ._visual_viewport = visual_viewport,
     });
 
+    self._style_manager = try StyleManager.init(self);
+    errdefer self._style_manager.deinit();
+
     const browser = session.browser;
     self._script_manager = ScriptManager.init(browser.allocator, browser.http_client, self);
     errdefer self._script_manager.deinit();
 
-    self.js = try browser.env.createContext(self);
+    self.js = try browser.env.createContext(self, .{
+        .identity = &session.identity,
+        .identity_arena = session.page_arena,
+        .call_arena = self.call_arena,
+    });
     errdefer self.js.deinit();
 
     document._page = self;
@@ -356,6 +367,7 @@ pub fn deinit(self: *Page, abort_http: bool) void {
     }
 
     self._script_manager.deinit();
+    self._style_manager.deinit();
 
     session.releaseArena(self.call_arena);
 }
@@ -437,6 +449,12 @@ pub fn navigate(self: *Page, request_url: [:0]const u8, opts: NavigateOpts) !voi
     if (is_about_blank or is_blob) {
         self.url = if (is_about_blank) "about:blank" else try self.arena.dupeZ(u8, request_url);
 
+        // even though this might be the same _data_ as `default_location`, we
+        // have to do this to make sure window.location is at a unique _address_.
+        // If we don't do this, mulitple window._location will have the same
+        // address and thus be mapped to the same v8::Object in the identity map.
+        self.window._location = try Location.init(self.url, self);
+
         if (is_blob) {
             // strip out blob:
             self.origin = try URL.getOrigin(self.arena, request_url[5.. :0]);
@@ -583,13 +601,34 @@ pub fn scheduleNavigation(self: *Page, request_url: []const u8, opts: NavigateOp
 // page that it's acting on.
 fn scheduleNavigationWithArena(originator: *Page, arena: Allocator, request_url: []const u8, opts: NavigateOpts, nt: Navigation) !void {
     const resolved_url, const is_about_blank = blk: {
+        if (URL.isCompleteHTTPUrl(request_url)) {
+            break :blk .{ try arena.dupeZ(u8, request_url), false };
+        }
+
         if (std.mem.eql(u8, request_url, "about:blank")) {
             // navigate will handle this special case
             break :blk .{ "about:blank", true };
         }
+
+        // request_url isn't a "complete" URL, so it has to be resolved with the
+        // originator's base. Unless, originator's base is "about:blank", in which
+        // case we have to walk up the parents and find a real base.
+        const page_base = base_blk: {
+            var maybe_not_blank_page = originator;
+            while (true) {
+                const maybe_base = maybe_not_blank_page.base();
+                if (std.mem.eql(u8, maybe_base, "about:blank") == false) {
+                    break :base_blk maybe_base;
+                }
+                // The orelse here is probably an invalid case, but there isn't
+                // anything we can do about it. It should never happen?
+                maybe_not_blank_page = maybe_not_blank_page.parent orelse break :base_blk "";
+            }
+        };
+
         const u = try URL.resolve(
             arena,
-            originator.base(),
+            page_base,
             request_url,
             .{ .always_dupe = true, .encode = true },
         );
@@ -2557,6 +2596,17 @@ pub fn removeNode(self: *Page, parent: *Node, child: *Node, opts: RemoveNodeOpts
         }
 
         Element.Html.Custom.invokeDisconnectedCallbackOnElement(el, self);
+
+        // If a <style> element is being removed, remove its sheet from the list
+        if (el.is(Element.Html.Style)) |style| {
+            if (style._sheet) |sheet| {
+                if (self.document._style_sheets) |sheets| {
+                    sheets.remove(sheet);
+                }
+                style._sheet = null;
+            }
+            self._style_manager.sheetModified();
+        }
     }
 }
 
@@ -2568,8 +2618,10 @@ pub fn appendAllChildren(self: *Page, parent: *Node, target: *Node) !void {
     self.domChanged();
     const dest_connected = target.isConnected();
 
-    var it = parent.childrenIterator();
+    // Use firstChild() instead of iterator to handle cases where callbacks
-    while (it.next()) |child| {
+    // (like custom element connectedCallback) modify the parent during iteration.
+    // The iterator captures "next" pointers that can become stale.
+    while (parent.firstChild()) |child| {
         // Check if child was connected BEFORE removing it from parent
         const child_was_connected = child.isConnected();
         self.removeNode(parent, child, .{ .will_be_reconnected = dest_connected });
@@ -2581,8 +2633,10 @@ pub fn insertAllChildrenBefore(self: *Page, fragment: *Node, parent: *Node, ref_
     self.domChanged();
     const dest_connected = parent.isConnected();
 
-    var it = fragment.childrenIterator();
+    // Use firstChild() instead of iterator to handle cases where callbacks
-    while (it.next()) |child| {
+    // (like custom element connectedCallback) modify the fragment during iteration.
+    // The iterator captures "next" pointers that can become stale.
+    while (fragment.firstChild()) |child| {
         // Check if child was connected BEFORE removing it from fragment
         const child_was_connected = child.isConnected();
         self.removeNode(fragment, child, .{ .will_be_reconnected = dest_connected });
@@ -3434,7 +3488,8 @@ pub fn submitForm(self: *Page, submitter_: ?*Element, form_: ?*Element.Html.Form
     };
 
     if (submit_opts.fire_event) {
-        const submit_event = try Event.initTrusted(comptime .wrap("submit"), .{ .bubbles = true, .cancelable = true }, self);
+        const submitter_html: ?*HtmlElement = if (submitter_) |s| s.is(HtmlElement) else null;
+        const submit_event = (try SubmitEvent.initTrusted(comptime .wrap("submit"), .{ .bubbles = true, .cancelable = true, .submitter = submitter_html }, self)).asEvent();
 
         // so submit_event is still valid when we check _prevent_default
         submit_event.acquireRef();
@@ -3532,10 +3587,12 @@ test "WebApi: Page" {
 }
 
 test "WebApi: Frames" {
-    const filter: testing.LogFilter = .init(&.{.js});
+    // TOO FLAKY, disabled for now
-    defer filter.deinit();
 
-    try testing.htmlRunner("frames", .{});
+    // const filter: testing.LogFilter = .init(&.{.js});
+    // defer filter.deinit();
+
+    // try testing.htmlRunner("frames", .{});
 }
 
 test "WebApi: Integration" {

src/browser/Runner.zig

@@ -0,0 +1,241 @@
+// 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 lp = @import("lightpanda");
+const builtin = @import("builtin");
+
+const log = @import("../log.zig");
+const App = @import("../App.zig");
+
+const Page = @import("Page.zig");
+const Session = @import("Session.zig");
+const Browser = @import("Browser.zig");
+const Factory = @import("Factory.zig");
+const HttpClient = @import("HttpClient.zig");
+
+const IS_DEBUG = builtin.mode == .Debug;
+
+const Runner = @This();
+
+page: *Page,
+session: *Session,
+http_client: *HttpClient,
+
+pub const Opts = struct {};
+
+pub fn init(session: *Session, _: Opts) !Runner {
+    const page = &(session.page orelse return error.NoPage);
+
+    return .{
+        .page = page,
+        .session = session,
+        .http_client = session.browser.http_client,
+    };
+}
+
+pub const WaitOpts = struct {
+    ms: u32,
+    until: lp.Config.WaitUntil = .done,
+};
+pub fn wait(self: *Runner, opts: WaitOpts) !void {
+    _ = try self._wait(false, opts);
+}
+
+pub const CDPWaitResult = enum {
+    done,
+    cdp_socket,
+};
+pub fn waitCDP(self: *Runner, opts: WaitOpts) !CDPWaitResult {
+    return self._wait(true, opts);
+}
+
+fn _wait(self: *Runner, comptime is_cdp: bool, opts: WaitOpts) !CDPWaitResult {
+    var timer = try std.time.Timer.start();
+    var ms_remaining = opts.ms;
+
+    const tick_opts = TickOpts{
+        .ms = 200,
+        .until = opts.until,
+    };
+    while (true) {
+        const tick_result = self._tick(is_cdp, tick_opts) catch |err| {
+            switch (err) {
+                error.JsError => {}, // already logged (with hopefully more context)
+                else => log.err(.browser, "session wait", .{
+                    .err = err,
+                    .url = self.page.url,
+                }),
+            }
+            return err;
+        };
+
+        const next_ms = switch (tick_result) {
+            .ok => |next_ms| next_ms,
+            .done => return .done,
+            .cdp_socket => if (comptime is_cdp) return .cdp_socket else unreachable,
+        };
+
+        const ms_elapsed = timer.lap() / 1_000_000;
+        if (ms_elapsed >= ms_remaining) {
+            return .done;
+        }
+        ms_remaining -= @intCast(ms_elapsed);
+        if (next_ms > 0) {
+            std.Thread.sleep(std.time.ns_per_ms * next_ms);
+        }
+    }
+}
+
+pub const TickOpts = struct {
+    ms: u32,
+    until: lp.Config.WaitUntil = .done,
+};
+
+pub const TickResult = union(enum) {
+    done,
+    ok: u32,
+};
+pub fn tick(self: *Runner, opts: TickOpts) !TickResult {
+    return switch (try self._tick(false, opts)) {
+        .ok => |ms| .{ .ok = ms },
+        .done => .done,
+        .cdp_socket => unreachable,
+    };
+}
+
+pub const CDPTickResult = union(enum) {
+    done,
+    cdp_socket,
+    ok: u32,
+};
+pub fn tickCDP(self: *Runner, opts: TickOpts) !CDPTickResult {
+    return self._tick(true, opts);
+}
+
+fn _tick(self: *Runner, comptime is_cdp: bool, opts: TickOpts) !CDPTickResult {
+    const page = self.page;
+    const http_client = self.http_client;
+
+    switch (page._parse_state) {
+        .pre, .raw, .text, .image => {
+            // The main page hasn't started/finished navigating.
+            // There's no JS to run, and no reason to run the scheduler.
+            if (http_client.active == 0 and (comptime is_cdp) == false) {
+                // haven't started navigating, I guess.
+                return .done;
+            }
+
+            // Either we have active http connections, or we're in CDP
+            // mode with an extra socket. Either way, we're waiting
+            // for http traffic
+            const http_result = try http_client.tick(@intCast(opts.ms));
+            if ((comptime is_cdp) and http_result == .cdp_socket) {
+                return .cdp_socket;
+            }
+            return .{ .ok = 0 };
+        },
+        .html, .complete => {
+            const session = self.session;
+            if (session.queued_navigation.items.len != 0) {
+                try session.processQueuedNavigation();
+                self.page = &session.page.?; // might have changed
+                return .{ .ok = 0 };
+            }
+            const browser = session.browser;
+
+            // The HTML page was parsed. We now either have JS scripts to
+            // download, or scheduled tasks to execute, or both.
+
+            // scheduler.run could trigger new http transfers, so do not
+            // store http_client.active BEFORE this call and then use
+            // it AFTER.
+            try browser.runMacrotasks();
+
+            // Each call to this runs scheduled load events.
+            try page.dispatchLoad();
+
+            const http_active = http_client.active;
+            const total_network_activity = http_active + http_client.intercepted;
+            if (page._notified_network_almost_idle.check(total_network_activity <= 2)) {
+                page.notifyNetworkAlmostIdle();
+            }
+            if (page._notified_network_idle.check(total_network_activity == 0)) {
+                page.notifyNetworkIdle();
+            }
+
+            if (http_active == 0 and (comptime is_cdp == false)) {
+                // we don't need to consider http_client.intercepted here
+                // because is_cdp is true, and that can only be
+                // the case when interception isn't possible.
+                if (comptime IS_DEBUG) {
+                    std.debug.assert(http_client.intercepted == 0);
+                }
+
+                if (browser.hasBackgroundTasks()) {
+                    // _we_ have nothing to run, but v8 is working on
+                    // background tasks. We'll wait for them.
+                    browser.waitForBackgroundTasks();
+                }
+
+                switch (opts.until) {
+                    .done => {},
+                    .domcontentloaded => if (page._load_state == .load or page._load_state == .complete) {
+                        return .done;
+                    },
+                    .load => if (page._load_state == .complete) {
+                        return .done;
+                    },
+                    .networkidle => if (page._notified_network_idle == .done) {
+                        return .done;
+                    },
+                }
+
+                // We never advertise a wait time of more than 20, there can
+                // always be new background tasks to run.
+                if (browser.msToNextMacrotask()) |ms_to_next_task| {
+                    return .{ .ok = @min(ms_to_next_task, 20) };
+                }
+                return .done;
+            }
+
+            // We're here because we either have active HTTP
+            // connections, or is_cdp == false (aka, there's
+            // an cdp_socket registered with the http client).
+            // We should continue to run tasks, so we minimize how long
+            // we'll poll for network I/O.
+            var ms_to_wait = @min(opts.ms, browser.msToNextMacrotask() orelse 200);
+            if (ms_to_wait > 10 and browser.hasBackgroundTasks()) {
+                // if we have background tasks, we don't want to wait too
+                // long for a message from the client. We want to go back
+                // to the top of the loop and run macrotasks.
+                ms_to_wait = 10;
+            }
+            const http_result = try http_client.tick(@intCast(@min(opts.ms, ms_to_wait)));
+            if ((comptime is_cdp) and http_result == .cdp_socket) {
+                return .cdp_socket;
+            }
+            return .{ .ok = 0 };
+        },
+        .err => |err| {
+            page._parse_state = .{ .raw_done = @errorName(err) };
+            return err;
+        },
+        .raw_done => return .done,
+    }
+}

src/browser/Session.zig

@@ -24,11 +24,13 @@ const log = @import("../log.zig");
 const App = @import("../App.zig");
 
 const js = @import("js/js.zig");
+const v8 = js.v8;
 const storage = @import("webapi/storage/storage.zig");
 const Navigation = @import("webapi/navigation/Navigation.zig");
 const History = @import("webapi/History.zig");
 
 const Page = @import("Page.zig");
+pub const Runner = @import("Runner.zig");
 const Browser = @import("Browser.zig");
 const Factory = @import("Factory.zig");
 const Notification = @import("../Notification.zig");
@@ -65,36 +67,41 @@ page_arena: Allocator,
 // Origin map for same-origin context sharing. Scoped to the root page lifetime.
 origins: std.StringHashMapUnmanaged(*js.Origin) = .empty,
 
+// Identity tracking for the main world. All main world contexts share this,
+// ensuring object identity works across same-origin frames.
+identity: js.Identity = .{},
+
 // Shared resources for all pages in this session.
 // These live for the duration of the page tree (root + frames).
 arena_pool: *ArenaPool,
 
-// In Debug, we use this to see if anything fails to release an arena back to
-// the pool.
-_arena_pool_leak_track: if (IS_DEBUG) std.AutoHashMapUnmanaged(usize, struct {
-    owner: []const u8,
-    count: usize,
-}) else void = if (IS_DEBUG) .empty else {},
-
 page: ?Page,
 
-queued_navigation: std.ArrayList(*Page),
+// Double buffer so that, as we process one list of queued navigations, new entries
+// are added to the separate buffer. This ensures that we don't end up with
+// endless navigation loops AND that we don't invalidate the list while iterating
+// if a new entry gets appended
+queued_navigation_1: std.ArrayList(*Page),
+queued_navigation_2: std.ArrayList(*Page),
+// pointer to either queued_navigation_1 or queued_navigation_2
+queued_navigation: *std.ArrayList(*Page),
+
 // Temporary buffer for about:blank navigations during processing.
 // We process async navigations first (safe from re-entrance), then sync
 // about:blank navigations (which may add to queued_navigation).
 queued_queued_navigation: std.ArrayList(*Page),
 
-page_id_gen: u32,
+page_id_gen: u32 = 0,
-frame_id_gen: u32,
+frame_id_gen: u32 = 0,
 
 pub fn init(self: *Session, browser: *Browser, notification: *Notification) !void {
     const allocator = browser.app.allocator;
     const arena_pool = browser.arena_pool;
 
-    const arena = try arena_pool.acquire();
+    const arena = try arena_pool.acquire(.{ .debug = "Session" });
     errdefer arena_pool.release(arena);
 
-    const page_arena = try arena_pool.acquire();
+    const page_arena = try arena_pool.acquire(.{ .debug = "Session.page_arena" });
     errdefer arena_pool.release(page_arena);
 
     self.* = .{
@@ -104,17 +111,18 @@ pub fn init(self: *Session, browser: *Browser, notification: *Notification) !voi
         .page_arena = page_arena,
         .factory = Factory.init(page_arena),
         .history = .{},
-        .page_id_gen = 0,
-        .frame_id_gen = 0,
         // The prototype (EventTarget) for Navigation is created when a Page is created.
         .navigation = .{ ._proto = undefined },
         .storage_shed = .{},
         .browser = browser,
-        .queued_navigation = .{},
+        .queued_navigation = undefined,
+        .queued_navigation_1 = .{},
+        .queued_navigation_2 = .{},
         .queued_queued_navigation = .{},
         .notification = notification,
         .cookie_jar = storage.Cookie.Jar.init(allocator),
     };
+    self.queued_navigation = &self.queued_navigation_1;
 }
 
 pub fn deinit(self: *Session) void {
@@ -171,32 +179,11 @@ pub const GetArenaOpts = struct {
 };
 
 pub fn getArena(self: *Session, opts: GetArenaOpts) !Allocator {
-    const allocator = try self.arena_pool.acquire();
+    return self.arena_pool.acquire(.{ .debug = opts.debug });
-    if (comptime IS_DEBUG) {
-        // Use session's arena (not page_arena) since page_arena gets reset between pages
-        const gop = try self._arena_pool_leak_track.getOrPut(self.arena, @intFromPtr(allocator.ptr));
-        if (gop.found_existing and gop.value_ptr.count != 0) {
-            log.err(.bug, "ArenaPool Double Use", .{ .owner = gop.value_ptr.*.owner });
-            @panic("ArenaPool Double Use");
-        }
-        gop.value_ptr.* = .{ .owner = opts.debug, .count = 1 };
-    }
-    return allocator;
 }
 
 pub fn releaseArena(self: *Session, allocator: Allocator) void {
-    if (comptime IS_DEBUG) {
+    self.arena_pool.release(allocator);
-        const found = self._arena_pool_leak_track.getPtr(@intFromPtr(allocator.ptr)).?;
-        if (found.count != 1) {
-            log.err(.bug, "ArenaPool Double Free", .{ .owner = found.owner, .count = found.count });
-            if (comptime builtin.is_test) {
-                @panic("ArenaPool Double Free");
-            }
-            return;
-        }
-        found.count = 0;
-    }
-    return self.arena_pool.release(allocator);
 }
 
 pub fn getOrCreateOrigin(self: *Session, key_: ?[]const u8) !*js.Origin {
@@ -237,18 +224,9 @@ pub fn releaseOrigin(self: *Session, origin: *js.Origin) void {
 /// Reset page_arena and factory for a clean slate.
 /// Called when root page is removed.
 fn resetPageResources(self: *Session) void {
-    // Check for arena leaks before releasing
+    self.identity.deinit();
-    if (comptime IS_DEBUG) {
+    self.identity = .{};
-        var it = self._arena_pool_leak_track.valueIterator();
-        while (it.next()) |value_ptr| {
-            if (value_ptr.count > 0) {
-                log.err(.bug, "ArenaPool Leak", .{ .owner = value_ptr.owner });
-            }
-        }
-        self._arena_pool_leak_track.clearRetainingCapacity();
-    }
 
-    // All origins should have been released when contexts were destroyed
     if (comptime IS_DEBUG) {
         std.debug.assert(self.origins.count() == 0);
     }
@@ -259,10 +237,9 @@ fn resetPageResources(self: *Session) void {
         while (it.next()) |value| {
             value.*.deinit(app);
         }
-        self.origins.clearRetainingCapacity();
+        self.origins = .empty;
     }
 
-    // Release old page_arena and acquire fresh one
     self.frame_id_gen = 0;
     self.arena_pool.reset(self.page_arena, 64 * 1024);
     self.factory = Factory.init(self.page_arena);
@@ -293,12 +270,6 @@ pub fn currentPage(self: *Session) ?*Page {
     return &(self.page orelse return null);
 }
 
-pub const WaitResult = enum {
-    done,
-    no_page,
-    cdp_socket,
-};
-
 pub fn findPageByFrameId(self: *Session, frame_id: u32) ?*Page {
     const page = self.currentPage() orelse return null;
     return findPageBy(page, "_frame_id", frame_id);
@@ -319,194 +290,12 @@ fn findPageBy(page: *Page, comptime field: []const u8, id: u32) ?*Page {
     return null;
 }
 
-pub fn wait(self: *Session, wait_ms: u32) WaitResult {
+pub fn runner(self: *Session, opts: Runner.Opts) !Runner {
-    var page = &(self.page orelse return .no_page);
+    return Runner.init(self, opts);
-    while (true) {
-        const wait_result = self._wait(page, wait_ms) catch |err| {
-            switch (err) {
-                error.JsError => {}, // already logged (with hopefully more context)
-                else => log.err(.browser, "session wait", .{
-                    .err = err,
-                    .url = page.url,
-                }),
-            }
-            return .done;
-        };
-
-        switch (wait_result) {
-            .done => {
-                if (self.queued_navigation.items.len == 0) {
-                    return .done;
-                }
-                self.processQueuedNavigation() catch return .done;
-                page = &self.page.?; // might have changed
-            },
-            else => |result| return result,
-        }
-    }
-}
-
-fn _wait(self: *Session, page: *Page, wait_ms: u32) !WaitResult {
-    var timer = try std.time.Timer.start();
-    var ms_remaining = wait_ms;
-
-    const browser = self.browser;
-    var http_client = browser.http_client;
-
-    // I'd like the page to know NOTHING about cdp_socket / CDP, but the
-    // fact is that the behavior of wait changes depending on whether or
-    // not we're using CDP.
-    // If we aren't using CDP, as soon as we think there's nothing left
-    // to do, we can exit - we'de done.
-    // But if we are using CDP, we should wait for the whole `wait_ms`
-    // because the http_click.tick() also monitors the CDP socket. And while
-    // we could let CDP poll http (like it does for HTTP requests), the fact
-    // is that we know more about the timing of stuff (e.g. how long to
-    // poll/sleep) in the page.
-    const exit_when_done = http_client.cdp_client == null;
-
-    while (true) {
-        switch (page._parse_state) {
-            .pre, .raw, .text, .image => {
-                // The main page hasn't started/finished navigating.
-                // There's no JS to run, and no reason to run the scheduler.
-                if (http_client.active == 0 and exit_when_done) {
-                    // haven't started navigating, I guess.
-                    return .done;
-                }
-                // Either we have active http connections, or we're in CDP
-                // mode with an extra socket. Either way, we're waiting
-                // for http traffic
-                if (try http_client.tick(@intCast(ms_remaining)) == .cdp_socket) {
-                    // exit_when_done is explicitly set when there isn't
-                    // an extra socket, so it should not be possibl to
-                    // get an cdp_socket message when exit_when_done
-                    // is true.
-                    if (IS_DEBUG) {
-                        std.debug.assert(exit_when_done == false);
-                    }
-
-                    // data on a socket we aren't handling, return to caller
-                    return .cdp_socket;
-                }
-            },
-            .html, .complete => {
-                if (self.queued_navigation.items.len != 0) {
-                    return .done;
-                }
-
-                // The HTML page was parsed. We now either have JS scripts to
-                // download, or scheduled tasks to execute, or both.
-
-                // scheduler.run could trigger new http transfers, so do not
-                // store http_client.active BEFORE this call and then use
-                // it AFTER.
-                try browser.runMacrotasks();
-
-                // Each call to this runs scheduled load events.
-                try page.dispatchLoad();
-
-                const http_active = http_client.active;
-                const total_network_activity = http_active + http_client.intercepted;
-                if (page._notified_network_almost_idle.check(total_network_activity <= 2)) {
-                    page.notifyNetworkAlmostIdle();
-                }
-                if (page._notified_network_idle.check(total_network_activity == 0)) {
-                    page.notifyNetworkIdle();
-                }
-
-                if (http_active == 0 and exit_when_done) {
-                    // we don't need to consider http_client.intercepted here
-                    // because exit_when_done is true, and that can only be
-                    // the case when interception isn't possible.
-                    if (comptime IS_DEBUG) {
-                        std.debug.assert(http_client.intercepted == 0);
-                    }
-
-                    var ms = blk: {
-                        // if (wait_ms - ms_remaining < 100) {
-                        //     if (comptime builtin.is_test) {
-                        //         return .done;
-                        //     }
-                        //     // Look, we want to exit ASAP, but we don't want
-                        //     // to exit so fast that we've run none of the
-                        //     // background jobs.
-                        //     break :blk 50;
-                        // }
-
-                        if (browser.hasBackgroundTasks()) {
-                            // _we_ have nothing to run, but v8 is working on
-                            // background tasks. We'll wait for them.
-                            browser.waitForBackgroundTasks();
-                            break :blk 20;
-                        }
-
-                        break :blk browser.msToNextMacrotask() orelse return .done;
-                    };
-
-                    if (ms > ms_remaining) {
-                        // Same as above, except we have a scheduled task,
-                        // it just happens to be too far into the future
-                        // compared to how long we were told to wait.
-                        if (!browser.hasBackgroundTasks()) {
-                            return .done;
-                        }
-                        // _we_ have nothing to run, but v8 is working on
-                        // background tasks. We'll wait for them.
-                        browser.waitForBackgroundTasks();
-                        ms = 20;
-                    }
-
-                    // We have a task to run in the not-so-distant future.
-                    // You might think we can just sleep until that task is
-                    // ready, but we should continue to run lowPriority tasks
-                    // in the meantime, and that could unblock things. So
-                    // we'll just sleep for a bit, and then restart our wait
-                    // loop to see if anything new can be processed.
-                    std.Thread.sleep(std.time.ns_per_ms * @as(u64, @intCast(@min(ms, 20))));
-                } else {
-                    // We're here because we either have active HTTP
-                    // connections, or exit_when_done == false (aka, there's
-                    // an cdp_socket registered with the http client).
-                    // We should continue to run tasks, so we minimize how long
-                    // we'll poll for network I/O.
-                    var ms_to_wait = @min(200, browser.msToNextMacrotask() orelse 200);
-                    if (ms_to_wait > 10 and browser.hasBackgroundTasks()) {
-                        // if we have background tasks, we don't want to wait too
-                        // long for a message from the client. We want to go back
-                        // to the top of the loop and run macrotasks.
-                        ms_to_wait = 10;
-                    }
-                    if (try http_client.tick(@min(ms_remaining, ms_to_wait)) == .cdp_socket) {
-                        // data on a socket we aren't handling, return to caller
-                        return .cdp_socket;
-                    }
-                }
-            },
-            .err => |err| {
-                page._parse_state = .{ .raw_done = @errorName(err) };
-                return err;
-            },
-            .raw_done => {
-                if (exit_when_done) {
-                    return .done;
-                }
-                // we _could_ http_client.tick(ms_to_wait), but this has
-                // the same result, and I feel is more correct.
-                return .no_page;
-            },
-        }
-
-        const ms_elapsed = timer.lap() / 1_000_000;
-        if (ms_elapsed >= ms_remaining) {
-            return .done;
-        }
-        ms_remaining -= @intCast(ms_elapsed);
-    }
 }
 
 pub fn scheduleNavigation(self: *Session, page: *Page) !void {
-    const list = &self.queued_navigation;
+    const list = self.queued_navigation;
 
     // Check if page is already queued
     for (list.items) |existing| {
@@ -519,8 +308,13 @@ pub fn scheduleNavigation(self: *Session, page: *Page) !void {
     return list.append(self.arena, page);
 }
 
-fn processQueuedNavigation(self: *Session) !void {
+pub fn processQueuedNavigation(self: *Session) !void {
-    const navigations = &self.queued_navigation;
+    const navigations = self.queued_navigation;
+    if (self.queued_navigation == &self.queued_navigation_1) {
+        self.queued_navigation = &self.queued_navigation_2;
+    } else {
+        self.queued_navigation = &self.queued_navigation_1;
+    }
 
     if (self.page.?._queued_navigation != null) {
         // This is both an optimization and a simplification of sorts. If the
@@ -536,7 +330,6 @@ fn processQueuedNavigation(self: *Session) !void {
     defer about_blank_queue.clearRetainingCapacity();
 
     // First pass: process async navigations (non-about:blank)
-    // These cannot cause re-entrant navigation scheduling
     for (navigations.items) |page| {
         const qn = page._queued_navigation.?;
 
@@ -551,7 +344,6 @@ fn processQueuedNavigation(self: *Session) !void {
         };
     }
 
-    // Clear the queue after first pass
     navigations.clearRetainingCapacity();
 
     // Second pass: process synchronous navigations (about:blank)
@@ -561,15 +353,17 @@ fn processQueuedNavigation(self: *Session) !void {
         try self.processFrameNavigation(page, qn);
     }
 
-    // Safety: Remove any about:blank navigations that were queued during the
+    // Safety: Remove any about:blank navigations that were queued during
-    // second pass to prevent infinite loops
+    // processing to prevent infinite loops. New navigations have been queued
+    // in the other buffer.
+    const new_navigations = self.queued_navigation;
     var i: usize = 0;
-    while (i < navigations.items.len) {
+    while (i < new_navigations.items.len) {
-        const page = navigations.items[i];
+        const page = new_navigations.items[i];
         if (page._queued_navigation) |qn| {
             if (qn.is_about_blank) {
-                log.warn(.page, "recursive about    blank", .{});
+                log.warn(.page, "recursive about blank", .{});
-                _ = navigations.swapRemove(i);
+                _ = self.queued_navigation.swapRemove(i);
                 continue;
             }
         }
@@ -632,16 +426,6 @@ fn processRootQueuedNavigation(self: *Session) !void {
 
     defer self.arena_pool.release(qn.arena);
 
-    // HACK
-    // Mark as released in tracking BEFORE removePage clears the map.
-    // We can't call releaseArena() because that would also return the arena
-    // to the pool, making the memory invalid before we use qn.url/qn.opts.
-    if (comptime IS_DEBUG) {
-        if (self._arena_pool_leak_track.getPtr(@intFromPtr(qn.arena.ptr))) |found| {
-            found.count = 0;
-        }
-    }
-
     self.removePage();
 
     self.page = @as(Page, undefined);
@@ -672,3 +456,36 @@ pub fn nextPageId(self: *Session) u32 {
     self.page_id_gen = id;
     return id;
 }
+
+// A type that has a finalizer can have its finalizer called one of two ways.
+// The first is from V8 via the WeakCallback we give to weakRef. But that isn't
+// guaranteed to fire, so we track this in finalizer_callbacks and call them on
+// page reset.
+pub const FinalizerCallback = struct {
+    arena: Allocator,
+    session: *Session,
+    ptr: *anyopaque,
+    global: v8.Global,
+    identity: *js.Identity,
+    zig_finalizer: *const fn (ptr: *anyopaque, session: *Session) void,
+
+    pub fn deinit(self: *FinalizerCallback) void {
+        self.zig_finalizer(self.ptr, self.session);
+        self.session.releaseArena(self.arena);
+    }
+
+    /// Release this item from the identity tracking maps (called after finalizer runs from V8)
+    pub fn releaseIdentity(self: *FinalizerCallback) void {
+        const session = self.session;
+        const id = @intFromPtr(self.ptr);
+
+        if (self.identity.identity_map.fetchRemove(id)) |kv| {
+            var global = kv.value;
+            v8.v8__Global__Reset(&global);
+        }
+
+        _ = self.identity.finalizer_callbacks.remove(id);
+
+        session.releaseArena(self.arena);
+    }
+};

src/browser/StyleManager.zig

@@ -0,0 +1,855 @@
+// Copyright (C) 2023-2026  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 String = @import("../string.zig").String;
+
+const Page = @import("Page.zig");
+
+const CssParser = @import("css/Parser.zig");
+const Element = @import("webapi/Element.zig");
+
+const Selector = @import("webapi/selector/Selector.zig");
+const SelectorParser = @import("webapi/selector/Parser.zig");
+const SelectorList = @import("webapi/selector/List.zig");
+
+const CSSStyleRule = @import("webapi/css/CSSStyleRule.zig");
+const CSSStyleSheet = @import("webapi/css/CSSStyleSheet.zig");
+const CSSStyleProperties = @import("webapi/css/CSSStyleProperties.zig");
+const CSSStyleProperty = @import("webapi/css/CSSStyleDeclaration.zig").Property;
+
+const Allocator = std.mem.Allocator;
+
+pub const VisibilityCache = std.AutoHashMapUnmanaged(*Element, bool);
+pub const PointerEventsCache = std.AutoHashMapUnmanaged(*Element, bool);
+
+// Tracks visibility-relevant CSS rules from <style> elements.
+// Rules are bucketed by their rightmost selector part for fast lookup.
+const StyleManager = @This();
+
+const Tag = Element.Tag;
+const RuleList = std.MultiArrayList(VisibilityRule);
+
+page: *Page,
+
+arena: Allocator,
+
+// Bucketed rules for fast lookup - keyed by rightmost selector part
+id_rules: std.StringHashMapUnmanaged(RuleList) = .empty,
+class_rules: std.StringHashMapUnmanaged(RuleList) = .empty,
+tag_rules: std.AutoHashMapUnmanaged(Tag, RuleList) = .empty,
+other_rules: RuleList = .empty, // universal, attribute, pseudo-class endings
+
+// Document order counter for tie-breaking equal specificity
+next_doc_order: u32 = 0,
+
+// When true, rules need to be rebuilt
+dirty: bool = false,
+
+pub fn init(page: *Page) !StyleManager {
+    return .{
+        .page = page,
+        .arena = try page.getArena(.{ .debug = "StyleManager" }),
+    };
+}
+
+pub fn deinit(self: *StyleManager) void {
+    self.page.releaseArena(self.arena);
+}
+
+fn parseSheet(self: *StyleManager, sheet: *CSSStyleSheet) !void {
+    if (sheet._css_rules) |css_rules| {
+        for (css_rules._rules.items) |rule| {
+            const style_rule = rule.is(CSSStyleRule) orelse continue;
+            try self.addRule(style_rule);
+        }
+        return;
+    }
+
+    const owner_node = sheet.getOwnerNode() orelse return;
+    if (owner_node.is(Element.Html.Style)) |style| {
+        const text = try style.asNode().getTextContentAlloc(self.arena);
+        var it = CssParser.parseStylesheet(text);
+        while (it.next()) |parsed_rule| {
+            try self.addRawRule(parsed_rule.selector, parsed_rule.block);
+        }
+    }
+}
+
+fn addRawRule(self: *StyleManager, selector_text: []const u8, block_text: []const u8) !void {
+    if (selector_text.len == 0) return;
+
+    var props = VisibilityProperties{};
+    var it = CssParser.parseDeclarationsList(block_text);
+    while (it.next()) |decl| {
+        const name = decl.name;
+        const val = decl.value;
+        if (std.ascii.eqlIgnoreCase(name, "display")) {
+            props.display_none = std.ascii.eqlIgnoreCase(val, "none");
+        } else if (std.ascii.eqlIgnoreCase(name, "visibility")) {
+            props.visibility_hidden = std.ascii.eqlIgnoreCase(val, "hidden") or std.ascii.eqlIgnoreCase(val, "collapse");
+        } else if (std.ascii.eqlIgnoreCase(name, "opacity")) {
+            props.opacity_zero = std.ascii.eqlIgnoreCase(val, "0");
+        } else if (std.ascii.eqlIgnoreCase(name, "pointer-events")) {
+            props.pointer_events_none = std.ascii.eqlIgnoreCase(val, "none");
+        }
+    }
+
+    if (!props.isRelevant()) return;
+
+    const selectors = SelectorParser.parseList(self.arena, selector_text, self.page) catch return;
+    for (selectors) |selector| {
+        const rightmost = if (selector.segments.len > 0) selector.segments[selector.segments.len - 1].compound else selector.first;
+        const bucket_key = getBucketKey(rightmost) orelse continue;
+        const rule = VisibilityRule{
+            .props = props,
+            .selector = selector,
+            .priority = (@as(u64, computeSpecificity(selector)) << 32) | @as(u64, self.next_doc_order),
+        };
+        self.next_doc_order += 1;
+
+        switch (bucket_key) {
+            .id => |id| {
+                const gop = try self.id_rules.getOrPut(self.arena, id);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .class => |class| {
+                const gop = try self.class_rules.getOrPut(self.arena, class);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .tag => |tag| {
+                const gop = try self.tag_rules.getOrPut(self.arena, tag);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .other => {
+                try self.other_rules.append(self.arena, rule);
+            },
+        }
+    }
+}
+
+pub fn sheetRemoved(self: *StyleManager) void {
+    self.dirty = true;
+}
+
+pub fn sheetModified(self: *StyleManager) void {
+    self.dirty = true;
+}
+
+/// Rebuilds the rule list from all document stylesheets.
+/// Called lazily when dirty flag is set and rules are needed.
+fn rebuildIfDirty(self: *StyleManager) !void {
+    if (!self.dirty) {
+        return;
+    }
+
+    self.dirty = false;
+    errdefer self.dirty = true;
+    const id_rules_count = self.id_rules.count();
+    const class_rules_count = self.class_rules.count();
+    const tag_rules_count = self.tag_rules.count();
+    const other_rules_count = self.other_rules.len;
+
+    self.page._session.arena_pool.resetRetain(self.arena);
+
+    self.next_doc_order = 0;
+
+    self.id_rules = .empty;
+    try self.id_rules.ensureTotalCapacity(self.arena, id_rules_count);
+
+    self.class_rules = .empty;
+    try self.class_rules.ensureTotalCapacity(self.arena, class_rules_count);
+
+    self.tag_rules = .empty;
+    try self.tag_rules.ensureTotalCapacity(self.arena, tag_rules_count);
+
+    self.other_rules = .{};
+    try self.other_rules.ensureTotalCapacity(self.arena, other_rules_count);
+
+    const sheets = self.page.document._style_sheets orelse return;
+    for (sheets._sheets.items) |sheet| {
+        self.parseSheet(sheet) catch |err| {
+            log.err(.browser, "StyleManager parseSheet", .{ .err = err });
+            return err;
+        };
+    }
+}
+
+// Check if an element is hidden based on options.
+// By default only checks display:none.
+// Walks up the tree to check ancestors.
+pub fn isHidden(self: *StyleManager, el: *Element, cache: ?*VisibilityCache, options: CheckVisibilityOptions) bool {
+    self.rebuildIfDirty() catch return false;
+
+    var current: ?*Element = el;
+
+    while (current) |elem| {
+        // Check cache first (only when checking all properties for caching consistency)
+        if (cache) |c| {
+            if (c.get(elem)) |hidden| {
+                if (hidden) {
+                    return true;
+                }
+                current = elem.parentElement();
+                continue;
+            }
+        }
+
+        const hidden = self.isElementHidden(elem, options);
+
+        // Store in cache
+        if (cache) |c| {
+            c.put(self.page.call_arena, elem, hidden) catch {};
+        }
+
+        if (hidden) {
+            return true;
+        }
+        current = elem.parentElement();
+    }
+
+    return false;
+}
+
+/// Check if a single element (not ancestors) is hidden.
+fn isElementHidden(self: *StyleManager, el: *Element, options: CheckVisibilityOptions) bool {
+    // Track best match per property (value + priority)
+    // Initialize priority to INLINE_PRIORITY for properties we don't care about - this makes
+    // the loop naturally skip them since no stylesheet rule can have priority >= INLINE_PRIORITY
+    var display_none: ?bool = null;
+    var display_priority: u64 = 0;
+
+    var visibility_hidden: ?bool = null;
+    var visibility_priority: u64 = 0;
+
+    var opacity_zero: ?bool = null;
+    var opacity_priority: u64 = 0;
+
+    // Check inline styles FIRST - they use INLINE_PRIORITY so no stylesheet can beat them
+    if (getInlineStyleProperty(el, comptime .wrap("display"), self.page)) |property| {
+        if (property._value.eql(comptime .wrap("none"))) {
+            return true; // Early exit for hiding value
+        }
+        display_none = false;
+        display_priority = INLINE_PRIORITY;
+    }
+
+    if (options.check_visibility) {
+        if (getInlineStyleProperty(el, comptime .wrap("visibility"), self.page)) |property| {
+            if (property._value.eql(comptime .wrap("hidden")) or property._value.eql(comptime .wrap("collapse"))) {
+                return true;
+            }
+            visibility_hidden = false;
+            visibility_priority = INLINE_PRIORITY;
+        }
+    } else {
+        // This can't be beat. Setting this means that, when checking rules
+        // we no longer have to check if options.check_visibility is enabled.
+        // We can just compare the priority.
+        visibility_priority = INLINE_PRIORITY;
+    }
+
+    if (options.check_opacity) {
+        if (getInlineStyleProperty(el, comptime .wrap("opacity"), self.page)) |property| {
+            if (property._value.eql(comptime .wrap("0"))) {
+                return true;
+            }
+            opacity_zero = false;
+            opacity_priority = INLINE_PRIORITY;
+        }
+    } else {
+        opacity_priority = INLINE_PRIORITY;
+    }
+
+    if (display_priority == INLINE_PRIORITY and visibility_priority == INLINE_PRIORITY and opacity_priority == INLINE_PRIORITY) {
+        return false;
+    }
+
+    // Helper to check a single rule
+    const Ctx = struct {
+        display_none: *?bool,
+        display_priority: *u64,
+        visibility_hidden: *?bool,
+        visibility_priority: *u64,
+        opacity_zero: *?bool,
+        opacity_priority: *u64,
+        el: *Element,
+        page: *Page,
+
+        fn checkRules(ctx: @This(), rules: *const RuleList) void {
+            if (ctx.display_priority.* == INLINE_PRIORITY and
+                ctx.visibility_priority.* == INLINE_PRIORITY and
+                ctx.opacity_priority.* == INLINE_PRIORITY)
+            {
+                return;
+            }
+
+            const priorities = rules.items(.priority);
+            const props_list = rules.items(.props);
+            const selectors = rules.items(.selector);
+
+            for (priorities, props_list, selectors) |p, props, selector| {
+                // Fast skip using packed u64 priority
+                if (p <= ctx.display_priority.* and p <= ctx.visibility_priority.* and p <= ctx.opacity_priority.*) {
+                    continue;
+                }
+
+                // Logic for property dominance
+                const dominated = (props.display_none == null or p <= ctx.display_priority.*) and
+                    (props.visibility_hidden == null or p <= ctx.visibility_priority.*) and
+                    (props.opacity_zero == null or p <= ctx.opacity_priority.*);
+
+                if (dominated) continue;
+
+                if (matchesSelector(ctx.el, selector, ctx.page)) {
+                    // Update best priorities
+                    if (props.display_none != null and p > ctx.display_priority.*) {
+                        ctx.display_none.* = props.display_none;
+                        ctx.display_priority.* = p;
+                    }
+                    if (props.visibility_hidden != null and p > ctx.visibility_priority.*) {
+                        ctx.visibility_hidden.* = props.visibility_hidden;
+                        ctx.visibility_priority.* = p;
+                    }
+                    if (props.opacity_zero != null and p > ctx.opacity_priority.*) {
+                        ctx.opacity_zero.* = props.opacity_zero;
+                        ctx.opacity_priority.* = p;
+                    }
+                }
+            }
+        }
+    };
+    const ctx = Ctx{
+        .display_none = &display_none,
+        .display_priority = &display_priority,
+        .visibility_hidden = &visibility_hidden,
+        .visibility_priority = &visibility_priority,
+        .opacity_zero = &opacity_zero,
+        .opacity_priority = &opacity_priority,
+        .el = el,
+        .page = self.page,
+    };
+
+    if (el.getAttributeSafe(comptime .wrap("id"))) |id| {
+        if (self.id_rules.get(id)) |rules| {
+            ctx.checkRules(&rules);
+        }
+    }
+
+    if (el.getAttributeSafe(comptime .wrap("class"))) |class_attr| {
+        var it = std.mem.tokenizeAny(u8, class_attr, &std.ascii.whitespace);
+        while (it.next()) |class| {
+            if (self.class_rules.get(class)) |rules| {
+                ctx.checkRules(&rules);
+            }
+        }
+    }
+
+    if (self.tag_rules.get(el.getTag())) |rules| {
+        ctx.checkRules(&rules);
+    }
+
+    ctx.checkRules(&self.other_rules);
+
+    return (display_none orelse false) or (visibility_hidden orelse false) or (opacity_zero orelse false);
+}
+
+/// Check if an element has pointer-events:none.
+/// Checks inline style first - if set, skips stylesheet lookup.
+/// Walks up the tree to check ancestors.
+pub fn hasPointerEventsNone(self: *StyleManager, el: *Element, cache: ?*PointerEventsCache) bool {
+    self.rebuildIfDirty() catch return false;
+
+    var current: ?*Element = el;
+
+    while (current) |elem| {
+        // Check cache first
+        if (cache) |c| {
+            if (c.get(elem)) |pe_none| {
+                if (pe_none) return true;
+                current = elem.parentElement();
+                continue;
+            }
+        }
+
+        const pe_none = self.elementHasPointerEventsNone(elem);
+
+        if (cache) |c| {
+            c.put(self.page.call_arena, elem, pe_none) catch {};
+        }
+
+        if (pe_none) {
+            return true;
+        }
+        current = elem.parentElement();
+    }
+
+    return false;
+}
+
+/// Check if a single element (not ancestors) has pointer-events:none.
+fn elementHasPointerEventsNone(self: *StyleManager, el: *Element) bool {
+    const page = self.page;
+
+    // Check inline style first
+    if (getInlineStyleProperty(el, .wrap("pointer-events"), page)) |property| {
+        if (property._value.eql(comptime .wrap("none"))) {
+            return true;
+        }
+        return false;
+    }
+
+    var result: ?bool = null;
+    var best_priority: u64 = 0;
+
+    // Helper to check a single rule
+    const checkRules = struct {
+        fn check(rules: *const RuleList, res: *?bool, current_priority: *u64, elem: *Element, p: *Page) void {
+            if (current_priority.* == INLINE_PRIORITY) return;
+
+            const priorities = rules.items(.priority);
+            const props_list = rules.items(.props);
+            const selectors = rules.items(.selector);
+
+            for (priorities, props_list, selectors) |priority, props, selector| {
+                if (priority <= current_priority.*) continue;
+                if (props.pointer_events_none == null) continue;
+
+                if (matchesSelector(elem, selector, p)) {
+                    res.* = props.pointer_events_none;
+                    current_priority.* = priority;
+                }
+            }
+        }
+    }.check;
+
+    if (el.getAttributeSafe(comptime .wrap("id"))) |id| {
+        if (self.id_rules.get(id)) |rules| {
+            checkRules(&rules, &result, &best_priority, el, page);
+        }
+    }
+
+    if (el.getAttributeSafe(comptime .wrap("class"))) |class_attr| {
+        var it = std.mem.tokenizeAny(u8, class_attr, &std.ascii.whitespace);
+        while (it.next()) |class| {
+            if (self.class_rules.get(class)) |rules| {
+                checkRules(&rules, &result, &best_priority, el, page);
+            }
+        }
+    }
+
+    if (self.tag_rules.get(el.getTag())) |rules| {
+        checkRules(&rules, &result, &best_priority, el, page);
+    }
+
+    checkRules(&self.other_rules, &result, &best_priority, el, page);
+
+    return result orelse false;
+}
+
+// Extracts visibility-relevant rules from a CSS rule.
+// Creates one VisibilityRule per selector (not per selector list) so each has correct specificity.
+// Buckets rules by their rightmost selector part for fast lookup.
+fn addRule(self: *StyleManager, style_rule: *CSSStyleRule) !void {
+    const selector_text = style_rule._selector_text;
+    if (selector_text.len == 0) {
+        return;
+    }
+
+    // Check if the rule has visibility-relevant properties
+    const style = style_rule._style orelse return;
+    const props = extractVisibilityProperties(style);
+    if (!props.isRelevant()) {
+        return;
+    }
+
+    // Parse the selector list
+    const selectors = SelectorParser.parseList(self.arena, selector_text, self.page) catch return;
+    if (selectors.len == 0) {
+        return;
+    }
+
+    // Create one rule per selector - each has its own specificity
+    // e.g., "#id, .class { display: none }" becomes two rules with different specificities
+    for (selectors) |selector| {
+        // Get the rightmost compound (last segment, or first if no segments)
+        const rightmost = if (selector.segments.len > 0)
+            selector.segments[selector.segments.len - 1].compound
+        else
+            selector.first;
+
+        // Find the bucketing key from rightmost compound
+        const bucket_key = getBucketKey(rightmost) orelse continue; // skip if dynamic pseudo-class
+
+        const rule = VisibilityRule{
+            .props = props,
+            .selector = selector,
+            .priority = (@as(u64, computeSpecificity(selector)) << 32) | @as(u64, self.next_doc_order),
+        };
+        self.next_doc_order += 1;
+
+        // Add to appropriate bucket
+        switch (bucket_key) {
+            .id => |id| {
+                const gop = try self.id_rules.getOrPut(self.arena, id);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .class => |class| {
+                const gop = try self.class_rules.getOrPut(self.arena, class);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .tag => |tag| {
+                const gop = try self.tag_rules.getOrPut(self.arena, tag);
+                if (!gop.found_existing) gop.value_ptr.* = .{};
+                try gop.value_ptr.append(self.arena, rule);
+            },
+            .other => {
+                try self.other_rules.append(self.arena, rule);
+            },
+        }
+    }
+}
+
+const BucketKey = union(enum) {
+    id: []const u8,
+    class: []const u8,
+    tag: Tag,
+    other,
+};
+
+/// Returns the best bucket key for a compound selector, or null if it contains
+/// a dynamic pseudo-class we should skip (hover, active, focus, etc.)
+/// Priority: id > class > tag > other
+fn getBucketKey(compound: Selector.Compound) ?BucketKey {
+    var best_key: BucketKey = .other;
+
+    for (compound.parts) |part| {
+        switch (part) {
+            .id => |id| {
+                best_key = .{ .id = id };
+            },
+            .class => |class| {
+                if (best_key != .id) {
+                    best_key = .{ .class = class };
+                }
+            },
+            .tag => |tag| {
+                if (best_key == .other) {
+                    best_key = .{ .tag = tag };
+                }
+            },
+            .tag_name => {
+                // Custom tag - put in other bucket (can't efficiently look up)
+                // Keep current best_key if we have something better
+            },
+            .pseudo_class => |pc| {
+                // Skip dynamic pseudo-classes - they depend on interaction state
+                switch (pc) {
+                    .hover, .active, .focus, .focus_within, .focus_visible, .visited, .target => {
+                        return null; // Skip this selector entirely
+                    },
+                    else => {},
+                }
+            },
+            .universal, .attribute => {},
+        }
+    }
+
+    return best_key;
+}
+
+/// Extracts visibility-relevant properties from a style declaration.
+fn extractVisibilityProperties(style: *CSSStyleProperties) VisibilityProperties {
+    var props = VisibilityProperties{};
+    const decl = style.asCSSStyleDeclaration();
+
+    if (decl.findProperty(comptime .wrap("display"))) |property| {
+        props.display_none = property._value.eql(comptime .wrap("none"));
+    }
+
+    if (decl.findProperty(comptime .wrap("visibility"))) |property| {
+        props.visibility_hidden = property._value.eql(comptime .wrap("hidden")) or property._value.eql(comptime .wrap("collapse"));
+    }
+
+    if (decl.findProperty(comptime .wrap("opacity"))) |property| {
+        props.opacity_zero = property._value.eql(comptime .wrap("0"));
+    }
+
+    if (decl.findProperty(.wrap("pointer-events"))) |property| {
+        props.pointer_events_none = property._value.eql(comptime .wrap("none"));
+    }
+
+    return props;
+}
+
+// Computes CSS specificity for a selector.
+// Returns packed value: (id_count << 20) | (class_count << 10) | element_count
+pub fn computeSpecificity(selector: Selector.Selector) u32 {
+    var ids: u32 = 0;
+    var classes: u32 = 0; // includes classes, attributes, pseudo-classes
+    var elements: u32 = 0; // includes elements, pseudo-elements
+
+    // Count specificity for first compound
+    countCompoundSpecificity(selector.first, &ids, &classes, &elements);
+
+    // Count specificity for subsequent segments
+    for (selector.segments) |segment| {
+        countCompoundSpecificity(segment.compound, &ids, &classes, &elements);
+    }
+
+    // Pack into single u32: (ids << 20) | (classes << 10) | elements
+    // This gives us 10 bits each, supporting up to 1023 of each type
+    return (@as(u32, @min(ids, 1023)) << 20) | (@as(u32, @min(classes, 1023)) << 10) | @min(elements, 1023);
+}
+
+fn countCompoundSpecificity(compound: Selector.Compound, ids: *u32, classes: *u32, elements: *u32) void {
+    for (compound.parts) |part| {
+        switch (part) {
+            .id => ids.* += 1,
+            .class => classes.* += 1,
+            .tag, .tag_name => elements.* += 1,
+            .universal => {}, // zero specificity
+            .attribute => classes.* += 1,
+            .pseudo_class => |pc| {
+                switch (pc) {
+                    // :where() has zero specificity
+                    .where => {},
+                    // :not(), :is(), :has() take specificity of their most specific argument
+                    .not, .is, .has => |nested| {
+                        var max_nested: u32 = 0;
+                        for (nested) |nested_sel| {
+                            const spec = computeSpecificity(nested_sel);
+                            if (spec > max_nested) max_nested = spec;
+                        }
+                        // Unpack and add to our counts
+                        ids.* += (max_nested >> 20) & 0x3FF;
+                        classes.* += (max_nested >> 10) & 0x3FF;
+                        elements.* += max_nested & 0x3FF;
+                    },
+                    // All other pseudo-classes count as class-level specificity
+                    else => classes.* += 1,
+                }
+            },
+        }
+    }
+}
+
+fn matchesSelector(el: *Element, selector: Selector.Selector, page: *Page) bool {
+    const node = el.asNode();
+    return SelectorList.matches(node, selector, node, page);
+}
+
+const VisibilityProperties = struct {
+    display_none: ?bool = null,
+    visibility_hidden: ?bool = null,
+    opacity_zero: ?bool = null,
+    pointer_events_none: ?bool = null,
+
+    // returne true if any field in VisibilityProperties is not null
+    fn isRelevant(self: VisibilityProperties) bool {
+        return self.display_none != null or
+            self.visibility_hidden != null or
+            self.opacity_zero != null or
+            self.pointer_events_none != null;
+    }
+};
+
+const VisibilityRule = struct {
+    selector: Selector.Selector, // Single selector, not a list
+    props: VisibilityProperties,
+
+    // Packed priority: (specificity << 32) | doc_order
+    priority: u64,
+};
+
+const CheckVisibilityOptions = struct {
+    check_opacity: bool = false,
+    check_visibility: bool = false,
+};
+
+// Inline styles always win over stylesheets - use max u64 as sentinel
+const INLINE_PRIORITY: u64 = std.math.maxInt(u64);
+
+fn getInlineStyleProperty(el: *Element, property_name: String, page: *Page) ?*CSSStyleProperty {
+    const style = el.getOrCreateStyle(page) catch |err| {
+        log.err(.browser, "StyleManager getOrCreateStyle", .{ .err = err });
+        return null;
+    };
+    return style.asCSSStyleDeclaration().findProperty(property_name);
+}
+
+const testing = @import("../testing.zig");
+test "StyleManager: computeSpecificity: element selector" {
+    // div -> (0, 0, 1)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .tag = .div }} },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: class selector" {
+    // .foo -> (0, 1, 0)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .class = "foo" }} },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1 << 10, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: id selector" {
+    // #bar -> (1, 0, 0)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .id = "bar" }} },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1 << 20, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: combined selector" {
+    // div.foo#bar -> (1, 1, 1)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .tag = .div },
+            .{ .class = "foo" },
+            .{ .id = "bar" },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual((1 << 20) | (1 << 10) | 1, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: universal selector" {
+    // * -> (0, 0, 0)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{.universal} },
+        .segments = &.{},
+    };
+    try testing.expectEqual(0, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: multiple classes" {
+    // .a.b.c -> (0, 3, 0)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .class = "a" },
+            .{ .class = "b" },
+            .{ .class = "c" },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual(3 << 10, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: descendant combinator" {
+    // div span -> (0, 0, 2)
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .tag = .div }} },
+        .segments = &.{
+            .{ .combinator = .descendant, .compound = .{ .parts = &.{.{ .tag = .span }} } },
+        },
+    };
+    try testing.expectEqual(2, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: :where() has zero specificity" {
+    // :where(.foo) -> (0, 0, 0) regardless of what's inside
+    const inner_selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .class = "foo" }} },
+        .segments = &.{},
+    };
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .pseudo_class = .{ .where = &.{inner_selector} } },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual(0, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: :not() takes inner specificity" {
+    // :not(.foo) -> (0, 1, 0) - takes specificity of .foo
+    const inner_selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .class = "foo" }} },
+        .segments = &.{},
+    };
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .pseudo_class = .{ .not = &.{inner_selector} } },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1 << 10, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: :is() takes most specific inner" {
+    // :is(.foo, #bar) -> (1, 0, 0) - takes the most specific (#bar)
+    const class_selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .class = "foo" }} },
+        .segments = &.{},
+    };
+    const id_selector = Selector.Selector{
+        .first = .{ .parts = &.{.{ .id = "bar" }} },
+        .segments = &.{},
+    };
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .pseudo_class = .{ .is = &.{ class_selector, id_selector } } },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1 << 20, computeSpecificity(selector));
+}
+
+test "StyleManager: computeSpecificity: pseudo-class (general)" {
+    // :hover -> (0, 1, 0) - pseudo-classes count as class-level
+    const selector = Selector.Selector{
+        .first = .{ .parts = &.{
+            .{ .pseudo_class = .hover },
+        } },
+        .segments = &.{},
+    };
+    try testing.expectEqual(1 << 10, computeSpecificity(selector));
+}
+
+test "StyleManager: document order tie-breaking" {
+    // When specificity is equal, higher doc_order (later in document) wins
+    const beats = struct {
+        fn f(spec: u32, doc_order: u32, best_spec: u32, best_doc_order: u32) bool {
+            return spec > best_spec or (spec == best_spec and doc_order > best_doc_order);
+        }
+    }.f;
+
+    // Higher specificity always wins regardless of doc_order
+    try testing.expect(beats(2, 0, 1, 10));
+    try testing.expect(!beats(1, 10, 2, 0));
+
+    // Equal specificity: higher doc_order wins
+    try testing.expect(beats(1, 5, 1, 3)); // doc_order 5 > 3
+    try testing.expect(!beats(1, 3, 1, 5)); // doc_order 3 < 5
+
+    // Equal specificity and doc_order: no win
+    try testing.expect(!beats(1, 5, 1, 5));
+}

src/browser/URL.zig

@@ -204,7 +204,7 @@ pub fn ensureEncoded(allocator: Allocator, url: [:0]const u8) ![:0]const u8 {
     return buf.items[0 .. buf.items.len - 1 :0];
 }
 
-const EncodeSet = enum { path, query, userinfo };
+const EncodeSet = enum { path, query, userinfo, fragment };
 
 fn percentEncodeSegment(allocator: Allocator, segment: []const u8, comptime encode_set: EncodeSet) ![]const u8 {
     // Check if encoding is needed
@@ -256,8 +256,10 @@ fn shouldPercentEncode(c: u8, comptime encode_set: EncodeSet) bool {
         ';', '=' => encode_set == .userinfo,
         // Separators: userinfo must encode these
         '/', ':', '@' => encode_set == .userinfo,
-        // '?' is allowed in queries but not in paths or userinfo
+        // '?' is allowed in queries only
         '?' => encode_set != .query,
+        // '#' is allowed in fragments only
+        '#' => encode_set != .fragment,
         // Everything else needs encoding (including space)
         else => true,
     };
@@ -323,14 +325,22 @@ pub fn getPassword(raw: [:0]const u8) []const u8 {
 }
 
 pub fn getPathname(raw: [:0]const u8) []const u8 {
-    const protocol_end = std.mem.indexOf(u8, raw, "://") orelse 0;
+    const protocol_end = std.mem.indexOf(u8, raw, "://");
-    const path_start = std.mem.indexOfScalarPos(u8, raw, if (protocol_end > 0) protocol_end + 3 else 0, '/') orelse raw.len;
+
+    // Handle scheme:path URLs like about:blank (no "://")
+    if (protocol_end == null) {
+        const colon_pos = std.mem.indexOfScalar(u8, raw, ':') orelse return "";
+        const path = raw[colon_pos + 1 ..];
+        const query_or_hash = std.mem.indexOfAny(u8, path, "?#") orelse path.len;
+        return path[0..query_or_hash];
+    }
+
+    const path_start = std.mem.indexOfScalarPos(u8, raw, protocol_end.? + 3, '/') orelse raw.len;
 
     const query_or_hash_start = std.mem.indexOfAnyPos(u8, raw, path_start, "?#") orelse raw.len;
 
     if (path_start >= query_or_hash_start) {
-        if (std.mem.indexOf(u8, raw, "://") != null) return "/";
+        return "/";
-        return "";
     }
 
     return raw[path_start..query_or_hash_start];
@@ -587,11 +597,13 @@ pub fn setPathname(current: [:0]const u8, value: []const u8, allocator: Allocato
     const search = getSearch(current);
     const hash = getHash(current);
 
+    const encoded = try percentEncodeSegment(allocator, value, .path);
+
     // Add / prefix if not present and value is not empty
-    const pathname = if (value.len > 0 and value[0] != '/')
+    const pathname = if (encoded.len > 0 and encoded[0] != '/')
-        try std.fmt.allocPrint(allocator, "/{s}", .{value})
+        try std.fmt.allocPrint(allocator, "/{s}", .{encoded})
     else
-        value;
+        encoded;
 
     return buildUrl(allocator, protocol, host, pathname, search, hash);
 }
@@ -602,11 +614,13 @@ pub fn setSearch(current: [:0]const u8, value: []const u8, allocator: Allocator)
     const pathname = getPathname(current);
     const hash = getHash(current);
 
+    const encoded = try percentEncodeSegment(allocator, value, .query);
+
     // Add ? prefix if not present and value is not empty
-    const search = if (value.len > 0 and value[0] != '?')
+    const search = if (encoded.len > 0 and value[0] != '?')
-        try std.fmt.allocPrint(allocator, "?{s}", .{value})
+        try std.fmt.allocPrint(allocator, "?{s}", .{encoded})
     else
-        value;
+        encoded;
 
     return buildUrl(allocator, protocol, host, pathname, search, hash);
 }
@@ -617,11 +631,13 @@ pub fn setHash(current: [:0]const u8, value: []const u8, allocator: Allocator) !
     const pathname = getPathname(current);
     const search = getSearch(current);
 
+    const encoded = try percentEncodeSegment(allocator, value, .fragment);
+
     // Add # prefix if not present and value is not empty
-    const hash = if (value.len > 0 and value[0] != '#')
+    const hash = if (encoded.len > 0 and encoded[0] != '#')
-        try std.fmt.allocPrint(allocator, "#{s}", .{value})
+        try std.fmt.allocPrint(allocator, "#{s}", .{encoded})
     else
-        value;
+        encoded;
 
     return buildUrl(allocator, protocol, host, pathname, search, hash);
 }
@@ -1414,3 +1430,22 @@ test "URL: getHost" {
     try testing.expectEqualSlices(u8, "example.com:8080", getHost("https://user:pass@example.com:8080/page"));
     try testing.expectEqualSlices(u8, "", getHost("not-a-url"));
 }
+
+test "URL: setPathname percent-encodes" {
+    // Use arena allocator to match production usage (setPathname makes intermediate allocations)
+    var arena = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+    const allocator = arena.allocator();
+
+    // Spaces must be encoded as %20
+    const result1 = try setPathname("http://a/", "c d", allocator);
+    try testing.expectEqualSlices(u8, "http://a/c%20d", result1);
+
+    // Already-encoded sequences must not be double-encoded
+    const result2 = try setPathname("https://example.com/path", "/already%20encoded", allocator);
+    try testing.expectEqualSlices(u8, "https://example.com/already%20encoded", result2);
+
+    // Query and hash must be preserved
+    const result3 = try setPathname("https://example.com/path?a=b#hash", "/new path", allocator);
+    try testing.expectEqualSlices(u8, "https://example.com/new%20path?a=b#hash", result3);
+}

src/browser/actions.zig

@@ -23,6 +23,8 @@ const Element = @import("webapi/Element.zig");
 const Event = @import("webapi/Event.zig");
 const MouseEvent = @import("webapi/event/MouseEvent.zig");
 const Page = @import("Page.zig");
+const Session = @import("Session.zig");
+const Selector = @import("webapi/selector/Selector.zig");
 
 pub fn click(node: *DOMNode, page: *Page) !void {
     const el = node.is(Element) orelse return error.InvalidNodeType;
@@ -102,3 +104,34 @@ pub fn scroll(node: ?*DOMNode, x: ?i32, y: ?i32, page: *Page) !void {
         };
     }
 }
+
+pub fn waitForSelector(selector: [:0]const u8, timeout_ms: u32, session: *Session) !*DOMNode {
+    var timer = try std.time.Timer.start();
+    var runner = try session.runner(.{});
+    try runner.wait(.{ .ms = timeout_ms, .until = .load });
+
+    while (true) {
+        const page = runner.page;
+        const element = Selector.querySelector(page.document.asNode(), selector, page) catch {
+            return error.InvalidSelector;
+        };
+
+        if (element) |el| {
+            return el.asNode();
+        }
+
+        const elapsed: u32 = @intCast(timer.read() / std.time.ns_per_ms);
+        if (elapsed >= timeout_ms) {
+            return error.Timeout;
+        }
+        switch (try runner.tick(.{ .ms = timeout_ms - elapsed })) {
+            .done => return error.Timeout,
+            .ok => |recommended_sleep_ms| {
+                if (recommended_sleep_ms > 0) {
+                    // guanrateed to be <= 20ms
+                    std.Thread.sleep(std.time.ns_per_ms * recommended_sleep_ms);
+                }
+            },
+        }
+    }
+}

src/browser/css/Parser.zig

@@ -293,3 +293,191 @@ fn isBang(token: Tokenizer.Token) bool {
         else => false,
     };
 }
+
+pub const Rule = struct {
+    selector: []const u8,
+    block: []const u8,
+};
+
+pub fn parseStylesheet(input: []const u8) RulesIterator {
+    return RulesIterator.init(input);
+}
+
+pub const RulesIterator = struct {
+    input: []const u8,
+    stream: TokenStream,
+    has_skipped_at_rule: bool = false,
+
+    pub fn init(input: []const u8) RulesIterator {
+        return .{
+            .input = input,
+            .stream = TokenStream.init(input),
+        };
+    }
+
+    pub fn next(self: *RulesIterator) ?Rule {
+        var selector_start: ?usize = null;
+        var selector_end: ?usize = null;
+
+        while (true) {
+            const peeked = self.stream.peek() orelse return null;
+
+            if (peeked.token == .curly_bracket_block) {
+                if (selector_start == null) {
+                    self.skipBlock();
+                    continue;
+                }
+
+                const open_brace = self.stream.next() orelse return null;
+                const block_start = open_brace.end;
+                var block_end = block_start;
+
+                var depth: usize = 1;
+                while (true) {
+                    const span = self.stream.next() orelse {
+                        block_end = self.input.len;
+                        break;
+                    };
+                    if (span.token == .curly_bracket_block) {
+                        depth += 1;
+                    } else if (span.token == .close_curly_bracket) {
+                        depth -= 1;
+                        if (depth == 0) {
+                            block_end = span.start;
+                            break;
+                        }
+                    }
+                }
+
+                var selector = self.input[selector_start.?..selector_end.?];
+                selector = std.mem.trim(u8, selector, &std.ascii.whitespace);
+
+                return .{
+                    .selector = selector,
+                    .block = self.input[block_start..block_end],
+                };
+            }
+
+            if (peeked.token == .at_keyword) {
+                self.has_skipped_at_rule = true;
+                self.skipAtRule();
+                selector_start = null;
+                selector_end = null;
+                continue;
+            }
+
+            if (selector_start == null and (isWhitespaceOrComment(peeked.token) or isSemicolon(peeked.token))) {
+                _ = self.stream.next();
+                continue;
+            }
+
+            const span = self.stream.next() orelse return null;
+            if (!isWhitespaceOrComment(span.token)) {
+                if (selector_start == null) selector_start = span.start;
+                selector_end = span.end;
+            }
+        }
+    }
+
+    fn skipBlock(self: *RulesIterator) void {
+        const span = self.stream.next() orelse return;
+        if (span.token != .curly_bracket_block) return;
+
+        var depth: usize = 1;
+        while (true) {
+            const next_span = self.stream.next() orelse return;
+            if (next_span.token == .curly_bracket_block) {
+                depth += 1;
+            } else if (next_span.token == .close_curly_bracket) {
+                depth -= 1;
+                if (depth == 0) return;
+            }
+        }
+    }
+
+    fn skipAtRule(self: *RulesIterator) void {
+        _ = self.stream.next(); // consume @keyword
+        var depth: usize = 0;
+        var saw_block = false;
+
+        while (true) {
+            const peeked = self.stream.peek() orelse return;
+            if (!saw_block and isSemicolon(peeked.token) and depth == 0) {
+                _ = self.stream.next();
+                return;
+            }
+
+            const span = self.stream.next() orelse return;
+            if (isWhitespaceOrComment(span.token)) continue;
+
+            if (span.token == .curly_bracket_block) {
+                depth += 1;
+                saw_block = true;
+            } else if (span.token == .close_curly_bracket) {
+                if (depth > 0) depth -= 1;
+                if (saw_block and depth == 0) return;
+            }
+        }
+    }
+};
+
+const testing = std.testing;
+
+test "RulesIterator: single rule" {
+    var it = RulesIterator.init(".test { color: red; }");
+    const rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings(".test", rule.selector);
+    try testing.expectEqualStrings(" color: red; ", rule.block);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: multiple rules" {
+    var it = RulesIterator.init("h1 { margin: 0; } p { padding: 10px; }");
+
+    var rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("h1", rule.selector);
+    try testing.expectEqualStrings(" margin: 0; ", rule.block);
+
+    rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("p", rule.selector);
+    try testing.expectEqualStrings(" padding: 10px; ", rule.block);
+
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: skips at-rules without block" {
+    var it = RulesIterator.init("@import url('style.css'); .test { color: red; }");
+
+    const rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings(".test", rule.selector);
+    try testing.expectEqualStrings(" color: red; ", rule.block);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: skips at-rules with block" {
+    var it = RulesIterator.init("@media screen { .test { color: blue; } } .test2 { color: green; }");
+
+    const rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings(".test2", rule.selector);
+    try testing.expectEqualStrings(" color: green; ", rule.block);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: comments and whitespace" {
+    var it = RulesIterator.init("  /* comment */  .test  /* comment */ { /* comment */ color: red; } \n\t");
+
+    const rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings(".test", rule.selector);
+    try testing.expectEqualStrings(" /* comment */ color: red; ", rule.block);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: top-level semicolons" {
+    var it = RulesIterator.init("*{}; ; p{}");
+    var rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("*", rule.selector);
+
+    rule = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("p", rule.selector);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}

src/browser/forms.zig

@@ -0,0 +1,460 @@
+// Copyright (C) 2023-2026  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 Page = @import("Page.zig");
+const TreeWalker = @import("webapi/TreeWalker.zig");
+const Element = @import("webapi/Element.zig");
+const Node = @import("webapi/Node.zig");
+
+const Allocator = std.mem.Allocator;
+
+pub const SelectOption = struct {
+    value: []const u8,
+    text: []const u8,
+
+    pub fn jsonStringify(self: *const SelectOption, jw: anytype) !void {
+        try jw.beginObject();
+        try jw.objectField("value");
+        try jw.write(self.value);
+        try jw.objectField("text");
+        try jw.write(self.text);
+        try jw.endObject();
+    }
+};
+
+pub const FormField = struct {
+    backendNodeId: ?u32 = null,
+    node: *Node,
+    tag_name: []const u8,
+    name: ?[]const u8,
+    input_type: ?[]const u8,
+    required: bool,
+    disabled: bool,
+    value: ?[]const u8,
+    placeholder: ?[]const u8,
+    options: []SelectOption,
+
+    pub fn jsonStringify(self: *const FormField, jw: anytype) !void {
+        try jw.beginObject();
+
+        if (self.backendNodeId) |id| {
+            try jw.objectField("backendNodeId");
+            try jw.write(id);
+        }
+
+        try jw.objectField("tagName");
+        try jw.write(self.tag_name);
+
+        if (self.name) |v| {
+            try jw.objectField("name");
+            try jw.write(v);
+        }
+
+        if (self.input_type) |v| {
+            try jw.objectField("inputType");
+            try jw.write(v);
+        }
+
+        try jw.objectField("required");
+        try jw.write(self.required);
+
+        try jw.objectField("disabled");
+        try jw.write(self.disabled);
+
+        if (self.value) |v| {
+            try jw.objectField("value");
+            try jw.write(v);
+        }
+
+        if (self.placeholder) |v| {
+            try jw.objectField("placeholder");
+            try jw.write(v);
+        }
+
+        if (self.options.len > 0) {
+            try jw.objectField("options");
+            try jw.beginArray();
+            for (self.options) |opt| {
+                try opt.jsonStringify(jw);
+            }
+            try jw.endArray();
+        }
+
+        try jw.endObject();
+    }
+};
+
+pub const FormInfo = struct {
+    backendNodeId: ?u32 = null,
+    node: *Node,
+    action: ?[]const u8,
+    method: ?[]const u8,
+    fields: []FormField,
+
+    pub fn jsonStringify(self: *const FormInfo, jw: anytype) !void {
+        try jw.beginObject();
+
+        if (self.backendNodeId) |id| {
+            try jw.objectField("backendNodeId");
+            try jw.write(id);
+        }
+
+        if (self.action) |v| {
+            try jw.objectField("action");
+            try jw.write(v);
+        }
+
+        if (self.method) |v| {
+            try jw.objectField("method");
+            try jw.write(v);
+        }
+
+        try jw.objectField("fields");
+        try jw.beginArray();
+        for (self.fields) |field| {
+            try field.jsonStringify(jw);
+        }
+        try jw.endArray();
+
+        try jw.endObject();
+    }
+};
+
+/// Populate backendNodeId on each form and its fields by registering
+/// their nodes in the given registry. Works with both CDP and MCP registries.
+pub fn registerNodes(forms_data: []FormInfo, registry: anytype) !void {
+    for (forms_data) |*form| {
+        const form_registered = try registry.register(form.node);
+        form.backendNodeId = form_registered.id;
+        for (form.fields) |*field| {
+            const field_registered = try registry.register(field.node);
+            field.backendNodeId = field_registered.id;
+        }
+    }
+}
+
+/// Collect all forms and their fields under `root`.
+/// Uses Form.getElements() to include fields outside the <form> that
+/// reference it via the form="id" attribute, matching browser behavior.
+/// `arena` must be an arena allocator — returned slices borrow its memory.
+pub fn collectForms(
+    arena: Allocator,
+    root: *Node,
+    page: *Page,
+) ![]FormInfo {
+    var forms: std.ArrayList(FormInfo) = .empty;
+
+    var tw = TreeWalker.Full.init(root, .{});
+    while (tw.next()) |node| {
+        const form = node.is(Element.Html.Form) orelse continue;
+        const el = form.asElement();
+
+        const fields = try collectFormFields(arena, form, page);
+        if (fields.len == 0) continue;
+
+        const action_attr = el.getAttributeSafe(comptime .wrap("action"));
+        const method_str = form.getMethod();
+
+        try forms.append(arena, .{
+            .node = node,
+            .action = if (action_attr) |a| if (a.len > 0) a else null else null,
+            .method = method_str,
+            .fields = fields,
+        });
+    }
+
+    return forms.items;
+}
+
+fn collectFormFields(
+    arena: Allocator,
+    form: *Element.Html.Form,
+    page: *Page,
+) ![]FormField {
+    var fields: std.ArrayList(FormField) = .empty;
+
+    var elements = try form.getElements(page);
+    var it = try elements.iterator();
+    while (it.next()) |el| {
+        const node = el.asNode();
+
+        const is_disabled = el.isDisabled();
+
+        if (el.is(Element.Html.Input)) |input| {
+            if (input._input_type == .hidden) continue;
+            if (input._input_type == .submit or input._input_type == .button or input._input_type == .image) continue;
+
+            try fields.append(arena, .{
+                .node = node,
+                .tag_name = "input",
+                .name = el.getAttributeSafe(comptime .wrap("name")),
+                .input_type = input._input_type.toString(),
+                .required = el.getAttributeSafe(comptime .wrap("required")) != null,
+                .disabled = is_disabled,
+                .value = input.getValue(),
+                .placeholder = el.getAttributeSafe(comptime .wrap("placeholder")),
+                .options = &.{},
+            });
+            continue;
+        }
+
+        if (el.is(Element.Html.TextArea)) |textarea| {
+            try fields.append(arena, .{
+                .node = node,
+                .tag_name = "textarea",
+                .name = el.getAttributeSafe(comptime .wrap("name")),
+                .input_type = null,
+                .required = el.getAttributeSafe(comptime .wrap("required")) != null,
+                .disabled = is_disabled,
+                .value = textarea.getValue(),
+                .placeholder = el.getAttributeSafe(comptime .wrap("placeholder")),
+                .options = &.{},
+            });
+            continue;
+        }
+
+        if (el.is(Element.Html.Select)) |select| {
+            const options = try collectSelectOptions(arena, node, page);
+
+            try fields.append(arena, .{
+                .node = node,
+                .tag_name = "select",
+                .name = el.getAttributeSafe(comptime .wrap("name")),
+                .input_type = null,
+                .required = el.getAttributeSafe(comptime .wrap("required")) != null,
+                .disabled = is_disabled,
+                .value = select.getValue(page),
+                .placeholder = null,
+                .options = options,
+            });
+            continue;
+        }
+
+        // Button elements from getElements() - skip (not fillable)
+    }
+
+    return fields.items;
+}
+
+fn collectSelectOptions(
+    arena: Allocator,
+    select_node: *Node,
+    page: *Page,
+) ![]SelectOption {
+    var options: std.ArrayList(SelectOption) = .empty;
+    const Option = Element.Html.Option;
+
+    var tw = TreeWalker.Full.init(select_node, .{});
+    while (tw.next()) |node| {
+        const el = node.is(Element) orelse continue;
+        const option = el.is(Option) orelse continue;
+
+        try options.append(arena, .{
+            .value = option.getValue(page),
+            .text = option.getText(page),
+        });
+    }
+
+    return options.items;
+}
+
+const testing = @import("../testing.zig");
+
+fn testForms(html: []const u8) ![]FormInfo {
+    const page = try testing.test_session.createPage();
+
+    const doc = page.window._document;
+    const div = try doc.createElement("div", null, page);
+    try page.parseHtmlAsChildren(div.asNode(), html);
+
+    return collectForms(page.call_arena, div.asNode(), page);
+}
+
+test "browser.forms: login form" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form action="/login" method="POST">
+        \\  <input type="email" name="email" required placeholder="Email">
+        \\  <input type="password" name="password" required>
+        \\  <input type="submit" value="Log In">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual("/login", forms[0].action.?);
+    try testing.expectEqual("post", forms[0].method.?);
+    try testing.expectEqual(2, forms[0].fields.len);
+    try testing.expectEqual("email", forms[0].fields[0].name.?);
+    try testing.expectEqual("email", forms[0].fields[0].input_type.?);
+    try testing.expect(forms[0].fields[0].required);
+    try testing.expect(!forms[0].fields[0].disabled);
+    try testing.expectEqual("password", forms[0].fields[1].name.?);
+}
+
+test "browser.forms: form with select" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <select name="color">
+        \\    <option value="red">Red</option>
+        \\    <option value="blue">Blue</option>
+        \\  </select>
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(1, forms[0].fields.len);
+    try testing.expectEqual("select", forms[0].fields[0].tag_name);
+    try testing.expectEqual(2, forms[0].fields[0].options.len);
+    try testing.expectEqual("red", forms[0].fields[0].options[0].value);
+    try testing.expectEqual("Red", forms[0].fields[0].options[0].text);
+}
+
+test "browser.forms: form with textarea" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form method="POST">
+        \\  <textarea name="message" placeholder="Your message"></textarea>
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(1, forms[0].fields.len);
+    try testing.expectEqual("textarea", forms[0].fields[0].tag_name);
+    try testing.expectEqual("Your message", forms[0].fields[0].placeholder.?);
+}
+
+test "browser.forms: empty form skipped" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form action="/empty">
+        \\  <p>No fields here</p>
+        \\</form>
+    );
+    try testing.expectEqual(0, forms.len);
+}
+
+test "browser.forms: hidden inputs excluded" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <input type="hidden" name="csrf" value="token123">
+        \\  <input type="text" name="username">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(1, forms[0].fields.len);
+    try testing.expectEqual("username", forms[0].fields[0].name.?);
+}
+
+test "browser.forms: multiple forms" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form action="/search" method="GET">
+        \\  <input type="text" name="q" placeholder="Search">
+        \\</form>
+        \\<form action="/login" method="POST">
+        \\  <input type="email" name="email">
+        \\  <input type="password" name="pass">
+        \\</form>
+    );
+    try testing.expectEqual(2, forms.len);
+    try testing.expectEqual(1, forms[0].fields.len);
+    try testing.expectEqual(2, forms[1].fields.len);
+}
+
+test "browser.forms: disabled fields flagged" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <input type="text" name="enabled_field">
+        \\  <input type="text" name="disabled_field" disabled>
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(2, forms[0].fields.len);
+    try testing.expect(!forms[0].fields[0].disabled);
+    try testing.expect(forms[0].fields[1].disabled);
+}
+
+test "browser.forms: disabled fieldset" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <fieldset disabled>
+        \\    <input type="text" name="in_disabled_fieldset">
+        \\  </fieldset>
+        \\  <input type="text" name="outside_fieldset">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(2, forms[0].fields.len);
+    try testing.expect(forms[0].fields[0].disabled);
+    try testing.expect(!forms[0].fields[1].disabled);
+}
+
+test "browser.forms: external field via form attribute" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<input type="text" name="external" form="myform">
+        \\<form id="myform" action="/submit">
+        \\  <input type="text" name="internal">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(2, forms[0].fields.len);
+}
+
+test "browser.forms: checkbox and radio return value attribute" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <input type="checkbox" name="agree" value="yes" checked>
+        \\  <input type="radio" name="color" value="red">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(2, forms[0].fields.len);
+    try testing.expectEqual("checkbox", forms[0].fields[0].input_type.?);
+    try testing.expectEqual("yes", forms[0].fields[0].value.?);
+    try testing.expectEqual("radio", forms[0].fields[1].input_type.?);
+    try testing.expectEqual("red", forms[0].fields[1].value.?);
+}
+
+test "browser.forms: form without action or method" {
+    defer testing.reset();
+    defer testing.test_session.removePage();
+    const forms = try testForms(
+        \\<form>
+        \\  <input type="text" name="q">
+        \\</form>
+    );
+    try testing.expectEqual(1, forms.len);
+    try testing.expectEqual(null, forms[0].action);
+    try testing.expectEqual("get", forms[0].method.?);
+    try testing.expectEqual(1, forms[0].fields.len);
+}

src/browser/interactive.zig

@@ -133,6 +133,8 @@ pub fn collectInteractiveElements(
     // so classify and getListenerTypes are both O(1) per element.
     const listener_targets = try buildListenerTargetMap(page, arena);
 
+    var css_cache: Element.PointerEventsCache = .empty;
+
     var results: std.ArrayList(InteractiveElement) = .empty;
 
     var tw = TreeWalker.Full.init(root, .{});
@@ -146,7 +148,7 @@ pub fn collectInteractiveElements(
             else => {},
         }
 
-        const itype = classifyInteractivity(el, html_el, listener_targets) orelse continue;
+        const itype = classifyInteractivity(page, el, html_el, listener_targets, &css_cache) orelse continue;
 
         const listener_types = getListenerTypes(
             el.asEventTarget(),
@@ -160,7 +162,7 @@ pub fn collectInteractiveElements(
             .name = try getAccessibleName(el, arena),
             .interactivity_type = itype,
             .listener_types = listener_types,
-            .disabled = isDisabled(el),
+            .disabled = el.isDisabled(),
             .tab_index = html_el.getTabIndex(),
             .id = el.getAttributeSafe(comptime .wrap("id")),
             .class = el.getAttributeSafe(comptime .wrap("class")),
@@ -210,10 +212,14 @@ pub fn buildListenerTargetMap(page: *Page, arena: Allocator) !ListenerTargetMap
 }
 
 pub fn classifyInteractivity(
+    page: *Page,
     el: *Element,
     html_el: *Element.Html,
     listener_targets: ListenerTargetMap,
+    cache: ?*Element.PointerEventsCache,
 ) ?InteractivityType {
+    if (el.hasPointerEventsNone(cache, page)) return null;
+
     // 1. Native interactive by tag
     switch (el.getTag()) {
         .button, .summary, .details, .select, .textarea => return .native,
@@ -406,36 +412,6 @@ fn getTextContent(node: *Node, arena: Allocator) !?[]const u8 {
     // strip out trailing space
     return arr.items[0 .. arr.items.len - 1];
 }
-fn isDisabled(el: *Element) bool {
-    if (el.getAttributeSafe(comptime .wrap("disabled")) != null) return true;
-    return isDisabledByFieldset(el);
-}
-
-/// Check if an element is disabled by an ancestor <fieldset disabled>.
-/// Per spec, elements inside the first <legend> child of a disabled fieldset
-/// are NOT disabled by that fieldset.
-fn isDisabledByFieldset(el: *Element) bool {
-    const element_node = el.asNode();
-    var current: ?*Node = element_node._parent;
-    while (current) |node| {
-        current = node._parent;
-        const ancestor = node.is(Element) orelse continue;
-
-        if (ancestor.getTag() == .fieldset and ancestor.getAttributeSafe(comptime .wrap("disabled")) != null) {
-            // Check if element is inside the first <legend> child of this fieldset
-            var child = ancestor.firstElementChild();
-            while (child) |c| {
-                if (c.getTag() == .legend) {
-                    if (c.asNode().contains(element_node)) return false;
-                    break;
-                }
-                child = c.nextElementSibling();
-            }
-            return true;
-        }
-    }
-    return false;
-}
 
 fn getInputType(el: *Element) ?[]const u8 {
     if (el.is(Element.Html.Input)) |input| {
@@ -554,6 +530,11 @@ test "browser.interactive: disabled by fieldset" {
     try testing.expect(!elements[1].disabled);
 }
 
+test "browser.interactive: pointer-events none" {
+    const elements = try testInteractive("<button style=\"pointer-events: none;\">Click me</button>");
+    try testing.expectEqual(0, elements.len);
+}
+
 test "browser.interactive: non-interactive div" {
     const elements = try testInteractive("<div>Just text</div>");
     try testing.expectEqual(0, elements.len);

src/browser/js/Context.zig

@@ -63,7 +63,9 @@ templates: []*const v8.FunctionTemplate,
 // Arena for the lifetime of the context
 arena: Allocator,
 
-// The page.call_arena
+// The call_arena for this context. For main world contexts this is
+// page.call_arena. For isolated world contexts this is a separate arena
+// owned by the IsolatedWorld.
 call_arena: Allocator,
 
 // Because calls can be nested (i.e.a function calling a callback),
@@ -79,6 +81,16 @@ local: ?*const js.Local = null,
 
 origin: *Origin,
 
+// Identity tracking for this context. For main world contexts, this points to
+// Session's Identity. For isolated world contexts (CDP inspector), this points
+// to IsolatedWorld's Identity. This ensures same-origin frames share object
+// identity while isolated worlds have separate identity tracking.
+identity: *js.Identity,
+
+// Allocator to use for identity map operations. For main world contexts this is
+// session.page_arena, for isolated worlds it's the isolated world's arena.
+identity_arena: Allocator,
+
 // Unlike other v8 types, like functions or objects, modules are not shared
 // across origins.
 global_modules: std.ArrayList(v8.Global) = .empty,
@@ -185,9 +197,8 @@ pub fn setOrigin(self: *Context, key: ?[]const u8) !void {
     lp.assert(self.origin.rc == 1, "Ref opaque origin", .{ .rc = self.origin.rc });
 
     const origin = try self.session.getOrCreateOrigin(key);
-    errdefer self.session.releaseOrigin(origin);
-    try origin.takeover(self.origin);
 
+    self.session.releaseOrigin(self.origin);
     self.origin = origin;
 
     {
@@ -203,16 +214,16 @@ pub fn setOrigin(self: *Context, key: ?[]const u8) !void {
 }
 
 pub fn trackGlobal(self: *Context, global: v8.Global) !void {
-    return self.origin.trackGlobal(global);
+    return self.identity.globals.append(self.identity_arena, global);
 }
 
 pub fn trackTemp(self: *Context, global: v8.Global) !void {
-    return self.origin.trackTemp(global);
+    return self.identity.temps.put(self.identity_arena, global.data_ptr, global);
 }
 
 pub fn weakRef(self: *Context, obj: anytype) void {
     const resolved = js.Local.resolveValue(obj);
-    const fc = self.origin.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
+    const fc = self.identity.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
         if (comptime IS_DEBUG) {
             // should not be possible
             std.debug.assert(false);
@@ -224,7 +235,7 @@ pub fn weakRef(self: *Context, obj: anytype) void {
 
 pub fn safeWeakRef(self: *Context, obj: anytype) void {
     const resolved = js.Local.resolveValue(obj);
-    const fc = self.origin.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
+    const fc = self.identity.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
         if (comptime IS_DEBUG) {
             // should not be possible
             std.debug.assert(false);
@@ -237,7 +248,7 @@ pub fn safeWeakRef(self: *Context, obj: anytype) void {
 
 pub fn strongRef(self: *Context, obj: anytype) void {
     const resolved = js.Local.resolveValue(obj);
-    const fc = self.origin.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
+    const fc = self.identity.finalizer_callbacks.get(@intFromPtr(resolved.ptr)) orelse {
         if (comptime IS_DEBUG) {
             // should not be possible
             std.debug.assert(false);
@@ -247,6 +258,48 @@ pub fn strongRef(self: *Context, obj: anytype) void {
     v8.v8__Global__ClearWeak(&fc.global);
 }
 
+pub const IdentityResult = struct {
+    value_ptr: *v8.Global,
+    found_existing: bool,
+};
+
+pub fn addIdentity(self: *Context, ptr: usize) !IdentityResult {
+    const gop = try self.identity.identity_map.getOrPut(self.identity_arena, ptr);
+    return .{
+        .value_ptr = gop.value_ptr,
+        .found_existing = gop.found_existing,
+    };
+}
+
+pub fn releaseTemp(self: *Context, global: v8.Global) void {
+    if (self.identity.temps.fetchRemove(global.data_ptr)) |kv| {
+        var g = kv.value;
+        v8.v8__Global__Reset(&g);
+    }
+}
+
+pub fn createFinalizerCallback(
+    self: *Context,
+    global: v8.Global,
+    ptr: *anyopaque,
+    zig_finalizer: *const fn (ptr: *anyopaque, session: *Session) void,
+) !*Session.FinalizerCallback {
+    const session = self.session;
+    const arena = try session.getArena(.{ .debug = "FinalizerCallback" });
+    errdefer session.releaseArena(arena);
+    const fc = try arena.create(Session.FinalizerCallback);
+    fc.* = .{
+        .arena = arena,
+        .session = session,
+        .ptr = ptr,
+        .global = global,
+        .zig_finalizer = zig_finalizer,
+        // Store identity pointer for cleanup when V8 GCs the object
+        .identity = self.identity,
+    };
+    return fc;
+}
+
 // Any operation on the context have to be made from a local.
 pub fn localScope(self: *Context, ls: *js.Local.Scope) void {
     const isolate = self.isolate;

src/browser/js/Env.zig

@@ -34,6 +34,7 @@ const Snapshot = @import("Snapshot.zig");
 const Inspector = @import("Inspector.zig");
 
 const Page = @import("../Page.zig");
+const Session = @import("../Session.zig");
 const Window = @import("../webapi/Window.zig");
 
 const JsApis = bridge.JsApis;
@@ -254,8 +255,15 @@ pub fn deinit(self: *Env) void {
     allocator.destroy(self.isolate_params);
 }
 
-pub fn createContext(self: *Env, page: *Page) !*Context {
+pub const ContextParams = struct {
-    const context_arena = try self.app.arena_pool.acquire();
+    identity: *js.Identity,
+    identity_arena: Allocator,
+    call_arena: Allocator,
+    debug_name: []const u8 = "Context",
+};
+
+pub fn createContext(self: *Env, page: *Page, params: ContextParams) !*Context {
+    const context_arena = try self.app.arena_pool.acquire(.{ .debug = params.debug_name });
     errdefer self.app.arena_pool.release(context_arena);
 
     const isolate = self.isolate;
@@ -300,33 +308,43 @@ pub fn createContext(self: *Env, page: *Page) !*Context {
         v8.v8__Object__SetAlignedPointerInInternalField(global_obj, 0, tao);
     }
 
-    // our window wrapped in a v8::Global
-    var global_global: v8.Global = undefined;
-    v8.v8__Global__New(isolate.handle, global_obj, &global_global);
-
     const context_id = self.context_id;
     self.context_id = context_id + 1;
 
-    const origin = try page._session.getOrCreateOrigin(null);
+    const session = page._session;
-    errdefer page._session.releaseOrigin(origin);
+    const origin = try session.getOrCreateOrigin(null);
+    errdefer session.releaseOrigin(origin);
 
     const context = try context_arena.create(Context);
     context.* = .{
         .env = self,
         .page = page,
-        .session = page._session,
         .origin = origin,
         .id = context_id,
+        .session = session,
         .isolate = isolate,
         .arena = context_arena,
         .handle = context_global,
         .templates = self.templates,
-        .call_arena = page.call_arena,
+        .call_arena = params.call_arena,
         .microtask_queue = microtask_queue,
         .script_manager = &page._script_manager,
         .scheduler = .init(context_arena),
+        .identity = params.identity,
+        .identity_arena = params.identity_arena,
     };
-    try context.origin.identity_map.putNoClobber(origin.arena, @intFromPtr(page.window), global_global);
+
+    {
+        // Multiple contexts can be created for the same Window (via CDP). We only
+        // need to register the first one.
+        const gop = try params.identity.identity_map.getOrPut(params.identity_arena, @intFromPtr(page.window));
+        if (gop.found_existing == false) {
+            // our window wrapped in a v8::Global
+            var global_global: v8.Global = undefined;
+            v8.v8__Global__New(isolate.handle, global_obj, &global_global);
+            gop.value_ptr.* = global_global;
+        }
+    }
 
     // Store a pointer to our context inside the v8 context so that, given
     // a v8 context, we can get our context out

src/browser/js/Function.zig

@@ -21,6 +21,7 @@ const js = @import("js.zig");
 const v8 = js.v8;
 
 const log = @import("../../log.zig");
+const Session = @import("../Session.zig");
 
 const Function = @This();
 
@@ -210,10 +211,10 @@ fn _persist(self: *const Function, comptime is_global: bool) !(if (is_global) Gl
     v8.v8__Global__New(ctx.isolate.handle, self.handle, &global);
     if (comptime is_global) {
         try ctx.trackGlobal(global);
-        return .{ .handle = global, .origin = {} };
+        return .{ .handle = global, .temps = {} };
     }
     try ctx.trackTemp(global);
-    return .{ .handle = global, .origin = ctx.origin };
+    return .{ .handle = global, .temps = &ctx.identity.temps };
 }
 
 pub fn tempWithThis(self: *const Function, value: anytype) !Temp {
@@ -237,7 +238,7 @@ const GlobalType = enum(u8) {
 fn G(comptime global_type: GlobalType) type {
     return struct {
         handle: v8.Global,
-        origin: if (global_type == .temp) *js.Origin else void,
+        temps: if (global_type == .temp) *std.AutoHashMapUnmanaged(usize, v8.Global) else void,
 
         const Self = @This();
 
@@ -257,7 +258,10 @@ fn G(comptime global_type: GlobalType) type {
         }
 
         pub fn release(self: *const Self) void {
-            self.origin.releaseTemp(self.handle);
+            if (self.temps.fetchRemove(self.handle.data_ptr)) |kv| {
+                var g = kv.value;
+                v8.v8__Global__Reset(&g);
+            }
         }
     };
 }

src/browser/js/Identity.zig

@@ -0,0 +1,76 @@
+// Copyright (C) 2023-2026  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/>.
+
+// Identity manages the mapping between Zig instances and their v8::Object wrappers.
+// This provides object identity semantics - the same Zig instance always maps to
+// the same JS object within a given Identity scope.
+//
+// Main world contexts share a single Identity (on Session), ensuring that
+// `window.top.document === top's document` works across same-origin frames.
+//
+// Isolated worlds (CDP inspector) have their own Identity, ensuring their
+// v8::Global wrappers don't leak into the main world.
+
+const std = @import("std");
+const js = @import("js.zig");
+
+const Session = @import("../Session.zig");
+
+const v8 = js.v8;
+const Allocator = std.mem.Allocator;
+
+const Identity = @This();
+
+// Maps Zig instance pointers to their v8::Global(Object) wrappers.
+identity_map: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
+
+// Tracked global v8 objects that need to be released on cleanup.
+globals: std.ArrayList(v8.Global) = .empty,
+
+// Temporary v8 globals that can be released early. Key is global.data_ptr.
+temps: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
+
+// Finalizer callbacks for weak references. Key is @intFromPtr of the Zig instance.
+finalizer_callbacks: std.AutoHashMapUnmanaged(usize, *Session.FinalizerCallback) = .empty,
+
+pub fn deinit(self: *Identity) void {
+    {
+        var it = self.finalizer_callbacks.valueIterator();
+        while (it.next()) |finalizer| {
+            finalizer.*.deinit();
+        }
+    }
+
+    {
+        var it = self.identity_map.valueIterator();
+        while (it.next()) |global| {
+            v8.v8__Global__Reset(global);
+        }
+    }
+
+    for (self.globals.items) |*global| {
+        v8.v8__Global__Reset(global);
+    }
+
+    {
+        var it = self.temps.valueIterator();
+        while (it.next()) |global| {
+            v8.v8__Global__Reset(global);
+        }
+    }
+}

src/browser/js/Local.zig

@@ -202,20 +202,20 @@ pub fn compileAndRun(self: *const Local, src: []const u8, name: ?[]const u8) !js
 //      we can just grab it from the identity_map)
 pub fn mapZigInstanceToJs(self: *const Local, js_obj_handle: ?*const v8.Object, value: anytype) !js.Object {
     const ctx = self.ctx;
-    const origin_arena = ctx.origin.arena;
+    const context_arena = ctx.arena;
 
     const T = @TypeOf(value);
     switch (@typeInfo(T)) {
         .@"struct" => {
             // Struct, has to be placed on the heap
-            const heap = try origin_arena.create(T);
+            const heap = try context_arena.create(T);
             heap.* = value;
             return self.mapZigInstanceToJs(js_obj_handle, heap);
         },
         .pointer => |ptr| {
             const resolved = resolveValue(value);
 
-            const gop = try ctx.origin.addIdentity(@intFromPtr(resolved.ptr));
+            const gop = try ctx.addIdentity(@intFromPtr(resolved.ptr));
             if (gop.found_existing) {
                 // we've seen this instance before, return the same object
                 return (js.Object.Global{ .handle = gop.value_ptr.* }).local(self);
@@ -244,7 +244,7 @@ pub fn mapZigInstanceToJs(self: *const Local, js_obj_handle: ?*const v8.Object,
                 // The TAO contains the pointer to our Zig instance as
                 // well as any meta data we'll need to use it later.
                 // See the TaggedOpaque struct for more details.
-                const tao = try origin_arena.create(TaggedOpaque);
+                const tao = try context_arena.create(TaggedOpaque);
                 tao.* = .{
                     .value = resolved.ptr,
                     .prototype_chain = resolved.prototype_chain.ptr,
@@ -276,10 +276,10 @@ pub fn mapZigInstanceToJs(self: *const Local, js_obj_handle: ?*const v8.Object,
                 // Instead, we check if the base has finalizer. The assumption
                 // here is that if a resolve type has a finalizer, then the base
                 // should have a finalizer too.
-                const fc = try ctx.origin.createFinalizerCallback(ctx.session, gop.value_ptr.*, resolved.ptr, resolved.finalizer_from_zig.?);
+                const fc = try ctx.createFinalizerCallback(gop.value_ptr.*, resolved.ptr, resolved.finalizer_from_zig.?);
                 {
                     errdefer fc.deinit();
-                    try ctx.origin.finalizer_callbacks.put(ctx.origin.arena, @intFromPtr(resolved.ptr), fc);
+                    try ctx.identity.finalizer_callbacks.put(ctx.identity_arena, @intFromPtr(resolved.ptr), fc);
                 }
 
                 conditionallyReference(value);

src/browser/js/Origin.zig

@@ -16,19 +16,21 @@
 // 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/>.
 
-// Origin represents the shared Zig<->JS bridge state for all contexts within
+// Origin represents the security token for contexts within the same origin.
-// the same origin. Multiple contexts (frames) from the same origin share a
+// Multiple contexts (frames) from the same origin share a single Origin,
-// single Origin, ensuring that JS objects maintain their identity across frames.
+// which provides the V8 SecurityToken that allows cross-context access.
+//
+// Note: Identity tracking (mapping Zig instances to v8::Objects) is managed
+// separately via js.Identity - Session has the main world Identity, and
+// IsolatedWorlds have their own Identity instances.
 
 const std = @import("std");
 const js = @import("js.zig");
 
 const App = @import("../../App.zig");
-const Session = @import("../Session.zig");
 
 const v8 = js.v8;
 const Allocator = std.mem.Allocator;
-const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const Origin = @This();
 
@@ -38,40 +40,12 @@ arena: Allocator,
 // The key, e.g. lightpanda.io:443
 key: []const u8,
 
-// Security token - all contexts in this realm must use the same v8::Value instance
+// Security token - all contexts in this origin must use the same v8::Value instance
 // as their security token for V8 to allow cross-context access
 security_token: v8.Global,
 
-// Serves two purposes. Like `global_objects`, this is used to free
-// every Global(Object) we've created during the lifetime of the realm.
-// More importantly, it serves as an identity map - for a given Zig
-// instance, we map it to the same Global(Object).
-// The key is the @intFromPtr of the Zig value
-identity_map: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
-
-// Some web APIs have to manage opaque values. Ideally, they use an
-// js.Object, but the js.Object has no lifetime guarantee beyond the
-// current call. They can call .persist() on their js.Object to get
-// a `Global(Object)`. We need to track these to free them.
-// This used to be a map and acted like identity_map; the key was
-// the @intFromPtr(js_obj.handle). But v8 can re-use address. Without
-// a reliable way to know if an object has already been persisted,
-// we now simply persist every time persist() is called.
-globals: std.ArrayList(v8.Global) = .empty,
-
-// Temp variants stored in HashMaps for O(1) early cleanup.
-// Key is global.data_ptr.
-temps: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
-
-// Any type that is stored in the identity_map which has a finalizer declared
-// will have its finalizer stored here. This is only used when shutting down
-// if v8 hasn't called the finalizer directly itself.
-finalizer_callbacks: std.AutoHashMapUnmanaged(usize, *FinalizerCallback) = .empty,
-
-taken_over: std.ArrayList(*Origin),
-
 pub fn init(app: *App, isolate: js.Isolate, key: []const u8) !*Origin {
-    const arena = try app.arena_pool.acquire();
+    const arena = try app.arena_pool.acquire(.{ .debug = "Origin" });
     errdefer app.arena_pool.release(arena);
 
     var hs: js.HandleScope = undefined;
@@ -88,175 +62,12 @@ pub fn init(app: *App, isolate: js.Isolate, key: []const u8) !*Origin {
         .rc = 1,
         .arena = arena,
         .key = owned_key,
-        .temps = .empty,
-        .globals = .empty,
-        .taken_over = .empty,
         .security_token = token_global,
     };
     return self;
 }
 
 pub fn deinit(self: *Origin, app: *App) void {
-    for (self.taken_over.items) |o| {
-        o.deinit(app);
-    }
-
-    // Call finalizers before releasing anything
-    {
-        var it = self.finalizer_callbacks.valueIterator();
-        while (it.next()) |finalizer| {
-            finalizer.*.deinit();
-        }
-    }
-
     v8.v8__Global__Reset(&self.security_token);
-
-    {
-        var it = self.identity_map.valueIterator();
-        while (it.next()) |global| {
-            v8.v8__Global__Reset(global);
-        }
-    }
-
-    for (self.globals.items) |*global| {
-        v8.v8__Global__Reset(global);
-    }
-
-    {
-        var it = self.temps.valueIterator();
-        while (it.next()) |global| {
-            v8.v8__Global__Reset(global);
-        }
-    }
-
     app.arena_pool.release(self.arena);
 }
-
-pub fn trackGlobal(self: *Origin, global: v8.Global) !void {
-    return self.globals.append(self.arena, global);
-}
-
-pub const IdentityResult = struct {
-    value_ptr: *v8.Global,
-    found_existing: bool,
-};
-
-pub fn addIdentity(self: *Origin, ptr: usize) !IdentityResult {
-    const gop = try self.identity_map.getOrPut(self.arena, ptr);
-    return .{
-        .value_ptr = gop.value_ptr,
-        .found_existing = gop.found_existing,
-    };
-}
-
-pub fn trackTemp(self: *Origin, global: v8.Global) !void {
-    return self.temps.put(self.arena, global.data_ptr, global);
-}
-
-pub fn releaseTemp(self: *Origin, global: v8.Global) void {
-    if (self.temps.fetchRemove(global.data_ptr)) |kv| {
-        var g = kv.value;
-        v8.v8__Global__Reset(&g);
-    }
-}
-
-/// Release an item from the identity_map (called after finalizer runs from V8)
-pub fn release(self: *Origin, item: *anyopaque) void {
-    var global = self.identity_map.fetchRemove(@intFromPtr(item)) orelse {
-        if (comptime IS_DEBUG) {
-            std.debug.assert(false);
-        }
-        return;
-    };
-    v8.v8__Global__Reset(&global.value);
-
-    // The item has been finalized, remove it from the finalizer callback so that
-    // we don't try to call it again on shutdown.
-    const kv = self.finalizer_callbacks.fetchRemove(@intFromPtr(item)) orelse {
-        if (comptime IS_DEBUG) {
-            std.debug.assert(false);
-        }
-        return;
-    };
-    const fc = kv.value;
-    fc.session.releaseArena(fc.arena);
-}
-
-pub fn createFinalizerCallback(
-    self: *Origin,
-    session: *Session,
-    global: v8.Global,
-    ptr: *anyopaque,
-    zig_finalizer: *const fn (ptr: *anyopaque, session: *Session) void,
-) !*FinalizerCallback {
-    const arena = try session.getArena(.{ .debug = "FinalizerCallback" });
-    errdefer session.releaseArena(arena);
-    const fc = try arena.create(FinalizerCallback);
-    fc.* = .{
-        .arena = arena,
-        .origin = self,
-        .session = session,
-        .ptr = ptr,
-        .global = global,
-        .zig_finalizer = zig_finalizer,
-    };
-    return fc;
-}
-
-pub fn takeover(self: *Origin, original: *Origin) !void {
-    const arena = self.arena;
-
-    try self.globals.ensureUnusedCapacity(arena, original.globals.items.len);
-    for (original.globals.items) |obj| {
-        self.globals.appendAssumeCapacity(obj);
-    }
-    original.globals.clearRetainingCapacity();
-
-    {
-        try self.temps.ensureUnusedCapacity(arena, original.temps.count());
-        var it = original.temps.iterator();
-        while (it.next()) |kv| {
-            try self.temps.put(arena, kv.key_ptr.*, kv.value_ptr.*);
-        }
-        original.temps.clearRetainingCapacity();
-    }
-
-    {
-        try self.finalizer_callbacks.ensureUnusedCapacity(arena, original.finalizer_callbacks.count());
-        var it = original.finalizer_callbacks.iterator();
-        while (it.next()) |kv| {
-            kv.value_ptr.*.origin = self;
-            try self.finalizer_callbacks.put(arena, kv.key_ptr.*, kv.value_ptr.*);
-        }
-        original.finalizer_callbacks.clearRetainingCapacity();
-    }
-
-    {
-        try self.identity_map.ensureUnusedCapacity(arena, original.identity_map.count());
-        var it = original.identity_map.iterator();
-        while (it.next()) |kv| {
-            try self.identity_map.put(arena, kv.key_ptr.*, kv.value_ptr.*);
-        }
-        original.identity_map.clearRetainingCapacity();
-    }
-
-    try self.taken_over.append(self.arena, original);
-}
-
-// A type that has a finalizer can have its finalizer called one of two ways.
-// The first is from V8 via the WeakCallback we give to weakRef. But that isn't
-// guaranteed to fire, so we track this in finalizer_callbacks and call them on
-// origin shutdown.
-pub const FinalizerCallback = struct {
-    arena: Allocator,
-    origin: *Origin,
-    session: *Session,
-    ptr: *anyopaque,
-    global: v8.Global,
-    zig_finalizer: *const fn (ptr: *anyopaque, session: *Session) void,
-
-    pub fn deinit(self: *FinalizerCallback) void {
-        self.zig_finalizer(self.ptr, self.session);
-        self.session.releaseArena(self.arena);
-    }
-};

src/browser/js/Promise.zig

@@ -16,9 +16,12 @@
 // 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.zig");
 const v8 = js.v8;
 
+const Session = @import("../Session.zig");
+
 const Promise = @This();
 
 local: *const js.Local,
@@ -63,10 +66,10 @@ fn _persist(self: *const Promise, comptime is_global: bool) !(if (is_global) Glo
     v8.v8__Global__New(ctx.isolate.handle, self.handle, &global);
     if (comptime is_global) {
         try ctx.trackGlobal(global);
-        return .{ .handle = global, .origin = {} };
+        return .{ .handle = global, .temps = {} };
     }
     try ctx.trackTemp(global);
-    return .{ .handle = global, .origin = ctx.origin };
+    return .{ .handle = global, .temps = &ctx.identity.temps };
 }
 
 pub const Temp = G(.temp);
@@ -80,7 +83,7 @@ const GlobalType = enum(u8) {
 fn G(comptime global_type: GlobalType) type {
     return struct {
         handle: v8.Global,
-        origin: if (global_type == .temp) *js.Origin else void,
+        temps: if (global_type == .temp) *std.AutoHashMapUnmanaged(usize, v8.Global) else void,
 
         const Self = @This();
 
@@ -96,7 +99,10 @@ fn G(comptime global_type: GlobalType) type {
         }
 
         pub fn release(self: *const Self) void {
-            self.origin.releaseTemp(self.handle);
+            if (self.temps.fetchRemove(self.handle.data_ptr)) |kv| {
+                var g = kv.value;
+                v8.v8__Global__Reset(&g);
+            }
         }
     };
 }

src/browser/js/String.zig

@@ -56,7 +56,7 @@ fn _toSlice(self: String, comptime null_terminate: bool, allocator: Allocator) !
 
 pub fn toSSO(self: String, comptime global: bool) !(if (global) SSO.Global else SSO) {
     if (comptime global) {
-        return .{ .str = try self.toSSOWithAlloc(self.local.ctx.origin.arena) };
+        return .{ .str = try self.toSSOWithAlloc(self.local.ctx.session.page_arena) };
     }
     return self.toSSOWithAlloc(self.local.call_arena);
 }

src/browser/js/Value.zig

@@ -25,6 +25,7 @@ const v8 = js.v8;
 const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const Allocator = std.mem.Allocator;
+const Session = @import("../Session.zig");
 
 const Value = @This();
 
@@ -300,10 +301,10 @@ fn _persist(self: *const Value, comptime is_global: bool) !(if (is_global) Globa
     v8.v8__Global__New(ctx.isolate.handle, self.handle, &global);
     if (comptime is_global) {
         try ctx.trackGlobal(global);
-        return .{ .handle = global, .origin = {} };
+        return .{ .handle = global, .temps = {} };
     }
     try ctx.trackTemp(global);
-    return .{ .handle = global, .origin = ctx.origin };
+    return .{ .handle = global, .temps = &ctx.identity.temps };
 }
 
 pub fn toZig(self: Value, comptime T: type) !T {
@@ -361,7 +362,7 @@ const GlobalType = enum(u8) {
 fn G(comptime global_type: GlobalType) type {
     return struct {
         handle: v8.Global,
-        origin: if (global_type == .temp) *js.Origin else void,
+        temps: if (global_type == .temp) *std.AutoHashMapUnmanaged(usize, v8.Global) else void,
 
         const Self = @This();
 
@@ -381,7 +382,10 @@ fn G(comptime global_type: GlobalType) type {
         }
 
         pub fn release(self: *const Self) void {
-            self.origin.releaseTemp(self.handle);
+            if (self.temps.fetchRemove(self.handle.data_ptr)) |kv| {
+                var g = kv.value;
+                v8.v8__Global__Reset(&g);
+            }
         }
     };
 }

src/browser/js/bridge.zig

@@ -27,7 +27,6 @@ const v8 = js.v8;
 
 const Caller = @import("Caller.zig");
 const Context = @import("Context.zig");
-const Origin = @import("Origin.zig");
 
 const IS_DEBUG = @import("builtin").mode == .Debug;
 
@@ -117,13 +116,12 @@ pub fn Builder(comptime T: type) type {
                 .from_v8 = struct {
                     fn wrap(handle: ?*const v8.WeakCallbackInfo) callconv(.c) void {
                         const ptr = v8.v8__WeakCallbackInfo__GetParameter(handle.?).?;
-                        const fc: *Origin.FinalizerCallback = @ptrCast(@alignCast(ptr));
+                        const fc: *Session.FinalizerCallback = @ptrCast(@alignCast(ptr));
 
-                        const origin = fc.origin;
                         const value_ptr = fc.ptr;
-                        if (origin.finalizer_callbacks.contains(@intFromPtr(value_ptr))) {
+                        if (fc.identity.finalizer_callbacks.contains(@intFromPtr(value_ptr))) {
                             func(@ptrCast(@alignCast(value_ptr)), false, fc.session);
-                            origin.release(value_ptr);
+                            fc.releaseIdentity();
                         } else {
                             // A bit weird, but v8 _requires_ that we release it
                             // If we don't. We'll 100% crash.
@@ -852,6 +850,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/event/TextEvent.zig"),
     @import("../webapi/event/InputEvent.zig"),
     @import("../webapi/event/PromiseRejectionEvent.zig"),
+    @import("../webapi/event/SubmitEvent.zig"),
     @import("../webapi/MessageChannel.zig"),
     @import("../webapi/MessagePort.zig"),
     @import("../webapi/media/MediaError.zig"),
@@ -901,6 +900,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/canvas/OffscreenCanvas.zig"),
     @import("../webapi/canvas/OffscreenCanvasRenderingContext2D.zig"),
     @import("../webapi/SubtleCrypto.zig"),
+    @import("../webapi/CryptoKey.zig"),
     @import("../webapi/Selection.zig"),
     @import("../webapi/ImageData.zig"),
 });

src/browser/js/js.zig

@@ -25,6 +25,7 @@ pub const Env = @import("Env.zig");
 pub const bridge = @import("bridge.zig");
 pub const Caller = @import("Caller.zig");
 pub const Origin = @import("Origin.zig");
+pub const Identity = @import("Identity.zig");
 pub const Context = @import("Context.zig");
 pub const Local = @import("Local.zig");
 pub const Inspector = @import("Inspector.zig");

src/browser/tests/animation/animation.html

@@ -15,10 +15,10 @@
     a1.play();
     cb.push(a1.playState);
   });
-  testing.eventually(() => testing.expectEqual(['idle', 'running', 'finished', true], cb));
+  testing.onload(() => testing.expectEqual(['idle', 'running', 'finished', true], cb));
 </script>
 
-<script id=startTime>
+<!-- <script id=startTime>
   let a2 = document.createElement('div').animate(null, null);
   // startTime defaults to null
   testing.expectEqual(null, a2.startTime);
@@ -39,7 +39,7 @@
   // onfinish callback should be scheduled and called asynchronously
   a3.onfinish = function() { calls.push('finish'); };
   a3.play();
-  testing.eventually(() => testing.expectEqual(['finish'], calls));
+  testing.onload(() => testing.expectEqual(['finish'], calls));
 </script>
 
 <script id=pause>
@@ -52,7 +52,7 @@
     a4.pause();
     cb4.push(a4.playState)
   });
-  testing.eventually(() => testing.expectEqual(['running', 'paused'], cb4));
+  testing.onload(() => testing.expectEqual(['running', 'paused'], cb4));
 </script>
 
 <script id=finish>
@@ -65,5 +65,6 @@
     cb5.push(a5.playState);
     a5.play();
   });
-  testing.eventually(() => testing.expectEqual(['idle', 'finished'], cb5));
+  testing.onload(() => testing.expectEqual(['idle', 'finished'], cb5));
 </script>
+ -->

src/browser/tests/css/font_face_set.html

@@ -71,7 +71,7 @@
 
     document.fonts.load("italic bold 16px Roboto");
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, loading);
       testing.expectEqual(true, loadingdone);
     });

src/browser/tests/css/stylesheet.html

@@ -419,3 +419,117 @@
     testing.expectEqual('anchor-size(--foo width, anchor-size(--bar height))', div.style.width);
 }
 </script>
+
+<script id="CSSStyleSheet_insertRule_deleteRule">
+{
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    const sheet = style.sheet;
+
+    testing.expectEqual(0, sheet.cssRules.length);
+
+    sheet.insertRule('.test { color: green; }', 0);
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual('.test', sheet.cssRules[0].selectorText);
+    testing.expectEqual('green', sheet.cssRules[0].style.color);
+
+    sheet.deleteRule(0);
+    testing.expectEqual(0, sheet.cssRules.length);
+
+    let caught = false;
+    try {
+        sheet.deleteRule(5);
+    } catch (e) {
+        caught = true;
+        testing.expectEqual('IndexSizeError', e.name);
+    }
+    testing.expectTrue(caught);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_default_index">
+{
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    const sheet = style.sheet;
+
+    testing.expectEqual(0, sheet.cssRules.length);
+
+    // Call without index, should default to 0
+    sheet.insertRule('.test-default { color: blue; }');
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual('.test-default', sheet.cssRules[0].selectorText);
+
+    // Insert another rule without index, should default to 0 and push the first one to index 1
+    sheet.insertRule('.test-at-0 { color: red; }');
+    testing.expectEqual(2, sheet.cssRules.length);
+    testing.expectEqual('.test-at-0', sheet.cssRules[0].selectorText);
+    testing.expectEqual('.test-default', sheet.cssRules[1].selectorText);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_semicolon">
+{
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    const sheet = style.sheet;
+
+    // Should not throw even with trailing semicolon
+    sheet.insertRule('*{};');
+    testing.expectEqual(1, sheet.cssRules.length);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_multiple_rules">
+{
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    const sheet = style.sheet;
+
+    let caught = false;
+    try {
+        sheet.insertRule('a { color: red; } b { color: blue; }');
+    } catch (e) {
+        caught = true;
+        testing.expectEqual('SyntaxError', e.name);
+    }
+    testing.expectTrue(caught);
+    testing.expectEqual(0, sheet.cssRules.length);
+}
+</script>
+
+<script id="CSSStyleSheet_replaceSync">
+{
+    const sheet = new CSSStyleSheet();
+    testing.expectEqual(0, sheet.cssRules.length);
+
+    sheet.replaceSync('.test { color: blue; }');
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual('.test', sheet.cssRules[0].selectorText);
+    testing.expectEqual('blue', sheet.cssRules[0].style.color);
+
+    let replacedAsync = false;
+    testing.async(async () => {
+        const result = await sheet.replace('.async-test { margin: 10px; }');
+        testing.expectTrue(result === sheet);
+        testing.expectEqual(1, sheet.cssRules.length);
+        testing.expectEqual('.async-test', sheet.cssRules[0].selectorText);
+        replacedAsync = true;
+    });
+    testing.onload(() => testing.expectTrue(replacedAsync));
+}
+</script>
+
+<script id="CSSStyleRule_cssText">
+{
+    const sheet = new CSSStyleSheet();
+    sheet.replaceSync('.test { color: red; margin: 10px; }');
+
+    // Check serialization format
+    const cssText = sheet.cssRules[0].cssText;
+    testing.expectTrue(cssText.includes('.test { '));
+    testing.expectTrue(cssText.includes('color: red;'));
+    testing.expectTrue(cssText.includes('margin: 10px;'));
+    testing.expectTrue(cssText.includes('}'));
+}
+</script>

src/browser/tests/document/replace_children.html

@@ -342,3 +342,4 @@
     testing.expectEqual('html', doc.lastChild.nodeName);
   }
 </script>
+

src/browser/tests/document/write.html

@@ -131,7 +131,7 @@
     document.open();
   }, 5);
 
-  testing.eventually(() => {
+  testing.onload(() => {
     // The element should be gone now
     const afterOpen = document.getElementById('will_be_removed');
     testing.expectEqual(null, afterOpen);

src/browser/tests/element/check_visibility.html

@@ -0,0 +1,226 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+<body></body>
+
+<!-
+<script id="inline_display_none">
+  {
+    const el = document.createElement("div");
+    document.body.appendChild(el);
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.style.display = "none";
+    testing.expectEqual(false, el.checkVisibility());
+
+    el.style.display = "block";
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.remove();
+  }
+</script>
+
+<script id="inline_visibility_hidden">
+  {
+    const el = document.createElement("div");
+    document.body.appendChild(el);
+
+    el.style.visibility = "hidden";
+    // Without visibilityProperty option, visibility:hidden is not checked
+    testing.expectEqual(true, el.checkVisibility());
+    // With visibilityProperty: true, visibility:hidden is detected
+    testing.expectEqual(false, el.checkVisibility({ visibilityProperty: true }));
+
+    el.style.visibility = "collapse";
+    testing.expectEqual(false, el.checkVisibility({ visibilityProperty: true }));
+
+    el.style.visibility = "visible";
+    testing.expectEqual(true, el.checkVisibility({ visibilityProperty: true }));
+
+    el.remove();
+  }
+</script>
+
+<script id="inline_opacity_zero">
+  {
+    const el = document.createElement("div");
+    document.body.appendChild(el);
+
+    el.style.opacity = "0";
+    // Without checkOpacity option, opacity:0 is not checked
+    testing.expectEqual(true, el.checkVisibility());
+    // With checkOpacity: true, opacity:0 is detected
+    testing.expectEqual(false, el.checkVisibility({ checkOpacity: true }));
+
+    el.style.opacity = "0.5";
+    testing.expectEqual(true, el.checkVisibility({ checkOpacity: true }));
+
+    el.style.opacity = "1";
+    testing.expectEqual(true, el.checkVisibility({ checkOpacity: true }));
+
+    el.remove();
+  }
+</script>
+
+<script id="parent_hidden_hides_child">
+  {
+    const parent = document.createElement("div");
+    const child = document.createElement("span");
+    parent.appendChild(child);
+    document.body.appendChild(parent);
+
+    testing.expectEqual(true, child.checkVisibility());
+
+    // display:none on parent hides children (no option needed)
+    parent.style.display = "none";
+    testing.expectEqual(false, child.checkVisibility());
+
+    // visibility:hidden on parent - needs visibilityProperty option
+    parent.style.display = "block";
+    parent.style.visibility = "hidden";
+    testing.expectEqual(true, child.checkVisibility()); // without option
+    testing.expectEqual(false, child.checkVisibility({ visibilityProperty: true }));
+
+    // opacity:0 on parent - needs checkOpacity option
+    parent.style.visibility = "visible";
+    parent.style.opacity = "0";
+    testing.expectEqual(true, child.checkVisibility()); // without option
+    testing.expectEqual(false, child.checkVisibility({ checkOpacity: true }));
+
+    parent.remove();
+  }
+</script>
+
+<style id="style-basic">
+  .hidden-by-class { display: none; }
+  .visible-by-class { display: block; }
+</style>
+<script id="style_tag_basic">
+  {
+    const el = document.createElement("div");
+    document.body.appendChild(el);
+
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.className = "hidden-by-class";
+    testing.expectEqual(false, el.checkVisibility());
+
+    el.className = "visible-by-class";
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.className = "";
+    el.remove();
+  }
+</script>
+
+<style id="style-specificity">
+  .spec-hidden { display: none; }
+  #spec-visible { display: block; }
+</style>
+<script id="specificity_id_beats_class">
+  {
+    const el = document.createElement("div");
+    el.id = "spec-visible";
+    el.className = "spec-hidden";
+    document.body.appendChild(el);
+
+    // ID selector (#spec-visible: display:block) should beat class selector (.spec-hidden: display:none)
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.remove();
+  }
+</script>
+
+<style id="style-order-1">
+  .order-test { display: none; }
+</style>
+<style id="style-order-2">
+  .order-test { display: block; }
+</style>
+<script id="rule_order_later_wins">
+  {
+    const el = document.createElement("div");
+    el.className = "order-test";
+    document.body.appendChild(el);
+
+    // Second style block should win (display: block)
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.remove();
+  }
+</script>
+
+<style id="style-override">
+  .should-be-hidden { display: none; }
+</style>
+<script id="inline_overrides_stylesheet">
+  {
+    const el = document.createElement("div");
+    el.className = "should-be-hidden";
+    document.body.appendChild(el);
+
+    testing.expectEqual(false, el.checkVisibility());
+
+    // Inline style should override
+    el.style.display = "block";
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.remove();
+  }
+</script>
+
+<script id="dynamic_style_element">
+  {
+    const el = document.createElement("div");
+    el.className = "dynamic-style-test";
+    document.body.appendChild(el);
+
+    testing.expectEqual(true, el.checkVisibility());
+
+    // Add a style element
+    const style = document.createElement("style");
+    style.textContent = ".dynamic-style-test { display: none; }";
+    document.head.appendChild(style);
+
+    testing.expectEqual(false, el.checkVisibility());
+
+    // Remove the style element
+    style.remove();
+    testing.expectEqual(true, el.checkVisibility());
+
+    el.remove();
+  }
+</script>
+
+<script id="deep_nesting">
+  {
+    const levels = 5;
+    let current = document.body;
+    const elements = [];
+
+    for (let i = 0; i < levels; i++) {
+      const el = document.createElement("div");
+      current.appendChild(el);
+      elements.push(el);
+      current = el;
+    }
+
+    // All should be visible
+    for (let i = 0; i < levels; i++) {
+      testing.expectEqual(true, elements[i].checkVisibility());
+    }
+
+    // Hide middle element
+    elements[2].style.display = "none";
+
+    // Elements 0, 1 should still be visible
+    testing.expectEqual(true, elements[0].checkVisibility());
+    testing.expectEqual(true, elements[1].checkVisibility());
+
+    // Elements 2, 3, 4 should be hidden
+    testing.expectEqual(false, elements[2].checkVisibility());
+    testing.expectEqual(false, elements[3].checkVisibility());
+    testing.expectEqual(false, elements[4].checkVisibility());
+
+    elements[0].remove();
+  }
+</script>

src/browser/tests/element/html/event_listeners.html

@@ -532,6 +532,6 @@
     testing.expectEqual(true, result);
   });
 
-  testing.eventually(() => testing.expectEqual(true, asyncBlockDispatched));
+  testing.onload(() => testing.expectEqual(true, asyncBlockDispatched));
 }
 </script>

src/browser/tests/element/html/form.html

@@ -463,3 +463,44 @@
   });
 }
 </script>
+
+<!-- Test: requestSubmit(submitter) sets SubmitEvent.submitter -->
+<form id="test_form_submitter" action="/should-not-navigate6" method="get">
+  <button id="submitter_btn" type="submit">Save</button>
+</form>
+
+<script id="requestSubmit_sets_submitter">
+{
+  const form = $('#test_form_submitter');
+  const btn = $('#submitter_btn');
+  let capturedSubmitter = undefined;
+
+  form.addEventListener('submit', (e) => {
+    e.preventDefault();
+    capturedSubmitter = e.submitter;
+  });
+
+  form.requestSubmit(btn);
+  testing.expectEqual(btn, capturedSubmitter);
+}
+</script>
+
+<!-- Test: requestSubmit() without submitter sets submitter to the form element -->
+<form id="test_form_submitter2" action="/should-not-navigate7" method="get">
+  <input type="text" name="q" value="test">
+</form>
+
+<script id="requestSubmit_default_submitter_is_form">
+{
+  const form = $('#test_form_submitter2');
+  let capturedSubmitter = undefined;
+
+  form.addEventListener('submit', (e) => {
+    e.preventDefault();
+    capturedSubmitter = e.submitter;
+  });
+
+  form.requestSubmit();
+  testing.expectEqual(form, capturedSubmitter);
+}
+</script>

src/browser/tests/element/html/image.html

@@ -29,10 +29,12 @@
 
     testing.expectEqual('', img.src);
     testing.expectEqual('', img.alt);
+    testing.expectEqual('', img.currentSrc);
 
     img.src = 'test.png';
     // src property returns resolved absolute URL
     testing.expectEqual(testing.BASE_URL + 'element/html/test.png', img.src);
+    testing.expectEqual(testing.BASE_URL + 'element/html/test.png', img.currentSrc);
     // getAttribute returns the raw attribute value
     testing.expectEqual('test.png', img.getAttribute('src'));
 
@@ -137,7 +139,7 @@
     });
   });
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
@@ -148,7 +150,7 @@
   const img = document.createElement("img");
   img.addEventListener("load", () => { fired = true; });
   document.body.appendChild(img);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -161,7 +163,7 @@
   document.body.appendChild(img);
   img.src = "https://cdn.lightpanda.io/website/assets/images/docs/hn.png";
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 

src/browser/tests/element/html/input.html

@@ -210,7 +210,7 @@
     });
     input.setSelectionRange(1, 4);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(5, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(input, lastEvent.target);
@@ -247,7 +247,7 @@
 
     input.select();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, eventCount);
       testing.expectEqual('select', lastEvent.type);
       testing.expectEqual(input, lastEvent.target);

src/browser/tests/element/html/link.html

@@ -54,7 +54,7 @@
   link.rel = 'stylesheet';
   link.addEventListener('load', () => { fired = true; });
   document.head.appendChild(link);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -66,7 +66,7 @@
   link.href = 'https://lightpanda.io/opensource-browser/15';
   link.addEventListener('load', () => { fired = true; });
   document.head.appendChild(link);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -81,7 +81,7 @@
   // then set href.
   link.href = 'https://lightpanda.io/opensource-browser/15';
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
@@ -98,7 +98,7 @@
   });
 
 
-  testing.eventually(() => {
+  testing.onload(() => {
     results.forEach((r) => {
       testing.expectEqual(true, r);
     });

src/browser/tests/element/html/media.html

@@ -236,9 +236,11 @@
   {
     const audio = document.createElement('audio');
     testing.expectEqual('', audio.src);
+    testing.expectEqual('', audio.currentSrc);
 
     audio.src = 'test.mp3';
     testing.expectEqual(testing.BASE_URL + 'element/html/test.mp3', audio.src);
+    testing.expectEqual(testing.BASE_URL + 'element/html/test.mp3', audio.currentSrc);
   }
 </script>
 

src/browser/tests/element/html/script/dynamic.html

@@ -8,14 +8,14 @@
   script1.async = false;
   script1.src = "dynamic1.js";
   document.getElementsByTagName('head')[0].appendChild(script1);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, loaded1);
   });
 </script>
 
 <script id=no_double_execute>
   document.getElementsByTagName('head')[0].appendChild(script1);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, loaded1);
   });
 </script>
@@ -25,7 +25,7 @@
   const script2a = document.createElement('script');
   script2a.src = "dynamic2.js";
   document.getElementsByTagName('head')[0].appendChild(script2a);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, loaded2);
   });
 </script>
@@ -38,7 +38,7 @@
 </script>
 
 <script id=src_after_append>
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, loaded2);
   });
 </script>

src/browser/tests/element/html/script/dynamic_inline.html

@@ -48,7 +48,7 @@
   s6.type = 'module';
   s6.textContent = 'window.module_executed = true;';
   document.head.appendChild(s6);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectTrue(window.module_executed);
   });
 </script>

src/browser/tests/element/html/script/script.html

@@ -21,7 +21,7 @@
    testing.expectEqual(testing.BASE_URL + 'element/html/script/empty.js', s.src);
    document.head.appendChild(s);
 
-   testing.eventually(() => {
+   testing.onload(() => {
       testing.expectEqual(true, dom_load);
       testing.expectEqual(true, attribute_load);
    });

src/browser/tests/element/html/slot.html

@@ -427,7 +427,7 @@
     div.setAttribute('slot', 'content');
     host.appendChild(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -455,7 +455,7 @@
 
     div.setAttribute('slot', 'other');
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -483,7 +483,7 @@
 
     div.remove();
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -511,7 +511,7 @@
 
     div.slot = 'other';
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }

src/browser/tests/element/html/style.html

@@ -128,6 +128,20 @@
     });
   });
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
+}
+</script>
+
+<script id="style-tag-content-parsing">
+{
+  const style = document.createElement("style");
+  style.textContent = '.content-test { padding: 5px; }';
+  document.head.appendChild(style);
+
+  const sheet = style.sheet;
+  testing.expectTrue(sheet instanceof CSSStyleSheet);
+  testing.expectEqual(1, sheet.cssRules.length);
+  testing.expectEqual('.content-test', sheet.cssRules[0].selectorText);
+  testing.expectEqual('5px', sheet.cssRules[0].style.padding);
 }
 </script>

src/browser/tests/element/html/textarea.html

@@ -256,7 +256,7 @@
 
     textarea.select();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, eventCount);
       testing.expectEqual('select', lastEvent.type);
       testing.expectEqual(textarea, lastEvent.target);
@@ -295,7 +295,7 @@
     });
     textarea.setSelectionRange(1, 4);
     
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(5, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(textarea, lastEvent.target);

src/browser/tests/element/replace_children.html

@@ -0,0 +1,139 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+
+<head>
+  <title>element.replaceChildren Tests</title>
+</head>
+<body>
+  <div id="test">Original content</div>
+</body>
+
+<script id=error_replace_with_self>
+  {
+    // Test that element.replaceChildren(element) throws HierarchyRequestError
+    const doc = document.implementation.createHTMLDocument("title");
+    testing.expectError('HierarchyRequest', () => {
+      doc.body.replaceChildren(doc.body);
+    });
+  }
+</script>
+
+<script id=error_replace_with_ancestor>
+  {
+    // Test that replacing with an ancestor throws HierarchyRequestError
+    const doc = document.implementation.createHTMLDocument("title");
+    const child = doc.createElement('div');
+    doc.body.appendChild(child);
+
+    testing.expectError('HierarchyRequest', () => {
+      child.replaceChildren(doc.body);
+    });
+  }
+</script>
+
+<script id=replace_children_basic>
+  {
+    // Test basic element.replaceChildren
+    const doc = document.implementation.createHTMLDocument("title");
+    const child1 = doc.createElement('div');
+    const child2 = doc.createElement('span');
+    doc.body.appendChild(child1);
+
+    doc.body.replaceChildren(child2);
+
+    testing.expectEqual(1, doc.body.childNodes.length);
+    testing.expectEqual(child2, doc.body.firstChild);
+    testing.expectEqual(null, child1.parentNode);
+  }
+</script>
+
+<script id=replace_children_empty>
+  {
+    // Test element.replaceChildren with no arguments removes all children
+    const doc = document.implementation.createHTMLDocument("title");
+    doc.body.appendChild(doc.createElement('div'));
+    doc.body.appendChild(doc.createElement('span'));
+
+    doc.body.replaceChildren();
+
+    testing.expectEqual(0, doc.body.childNodes.length);
+  }
+</script>
+
+<script id=replace_children_fragment>
+  {
+    // Test element.replaceChildren with DocumentFragment
+    const doc = document.implementation.createHTMLDocument("title");
+    const frag = doc.createDocumentFragment();
+    frag.appendChild(doc.createElement('div'));
+    frag.appendChild(doc.createElement('span'));
+
+    doc.body.replaceChildren(frag);
+
+    testing.expectEqual(2, doc.body.childNodes.length);
+    testing.expectEqual('DIV', doc.body.firstChild.tagName);
+    testing.expectEqual('SPAN', doc.body.lastChild.tagName);
+    testing.expectEqual(0, frag.childNodes.length);
+  }
+</script>
+
+<script id=error_fragment_replace_with_self>
+  {
+    // Test that replacing with a fragment containing self throws
+    const doc = document.implementation.createHTMLDocument("title");
+    const frag = doc.createDocumentFragment();
+    const child = doc.createElement('div');
+    frag.appendChild(child);
+
+    testing.expectError('HierarchyRequest', () => {
+      child.replaceChildren(frag);
+    });
+  }
+</script>
+
+<script id=replace_children_text>
+  {
+    // Test element.replaceChildren with text
+    const doc = document.implementation.createHTMLDocument("title");
+    doc.body.appendChild(doc.createElement('div'));
+
+    doc.body.replaceChildren('Hello', 'World');
+
+    testing.expectEqual(2, doc.body.childNodes.length);
+    testing.expectEqual('Hello', doc.body.firstChild.textContent);
+    testing.expectEqual('World', doc.body.lastChild.textContent);
+  }
+</script>
+
+<script id=replace_children_mixed>
+  {
+    // Test element.replaceChildren with mixed nodes and text
+    const doc = document.implementation.createHTMLDocument("title");
+    const span = doc.createElement('span');
+    span.textContent = 'middle';
+
+    doc.body.replaceChildren('start', span, 'end');
+
+    testing.expectEqual(3, doc.body.childNodes.length);
+    testing.expectEqual('start', doc.body.childNodes[0].textContent);
+    testing.expectEqual('SPAN', doc.body.childNodes[1].tagName);
+    testing.expectEqual('end', doc.body.childNodes[2].textContent);
+  }
+</script>
+
+<script id=replace_children_reparents>
+  {
+    // Test that replaceChildren properly reparents nodes from another parent
+    const doc = document.implementation.createHTMLDocument("title");
+    const div1 = doc.createElement('div');
+    const div2 = doc.createElement('div');
+    const child = doc.createElement('span');
+
+    div1.appendChild(child);
+    testing.expectEqual(div1, child.parentNode);
+
+    div2.replaceChildren(child);
+    testing.expectEqual(div2, child.parentNode);
+    testing.expectEqual(0, div1.childNodes.length);
+  }
+</script>

src/browser/tests/event/abort_controller.html

@@ -242,7 +242,7 @@
 
 <script id=abortsignal_timeout>
   var s3 = AbortSignal.timeout(10);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, s3.aborted);
     testing.expectEqual('TimeoutError', s3.reason);
     testing.expectError('Error: TimeoutError', () => {

src/browser/tests/event/message.html

@@ -61,7 +61,7 @@
 
   window.postMessage('test data', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('test data', receivedEvent.data);
     testing.expectEqual(window, receivedEvent.source);
     testing.expectEqual('message', receivedEvent.type);
@@ -81,7 +81,7 @@
   const testObj = { type: 'test', value: 123, nested: { key: 'value' } };
   window.postMessage(testObj, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(testObj, receivedData);
   });
 }
@@ -111,7 +111,7 @@
 
   window.postMessage(42, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(42, received);
   });
 }
@@ -129,7 +129,7 @@
   const arr = [1, 2, 3, 'test'];
   window.postMessage(arr, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(arr, received);
   });
 }
@@ -146,7 +146,7 @@
 
   window.postMessage(null, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(null, received);
   });
 }
@@ -163,7 +163,7 @@
 
   window.postMessage('test', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('http://127.0.0.1:9582', receivedOrigin);
   });
 }

src/browser/tests/event/message_multiple_listeners.html

@@ -12,7 +12,7 @@
 
   window.postMessage('trigger', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, count);
   });
 }

src/browser/tests/frames/frames.html

@@ -28,7 +28,7 @@
   $('#f2').src = 'support/sub2.html';
   testing.expectEqual(true, true);
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(undefined, window[20]);
 
     testing.expectEqual(window, window[1].top);
@@ -84,7 +84,7 @@
     f3.src = 'invalid'; // still fires load!
     document.documentElement.appendChild(f3);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('f1_onload_loaded', window.f1_onload);
       testing.expectEqual(true, f3_load_event);
     });
@@ -98,7 +98,7 @@
     f4.src = "about:blank";
     document.documentElement.appendChild(f4);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual("<html><head></head><body></body></html>", f4.contentDocument.documentElement.outerHTML);
     });
   }
@@ -112,7 +112,7 @@
     document.documentElement.appendChild(f5);
     f5.src = "about:blank";
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual("<html><head></head><body></body></html>", f5.contentDocument.documentElement.outerHTML);
     });
   }
@@ -120,9 +120,10 @@
 
 <script id=link_click>
   testing.async(async (restore) => {
+    let f6;
     await new Promise((resolve) => {
       let count = 0;
-      let f6 = document.createElement('iframe');
+      f6 = document.createElement('iframe');
       f6.id = 'f6';
       f6.addEventListener('load', () => {
         if (++count == 2) {
@@ -139,8 +140,19 @@
   });
 </script>
 
+<script id=about_blank_nav>
+  {
+    let i = document.createElement('iframe');
+    document.documentElement.appendChild(i);
+    i.contentWindow.location.href = 'support/page.html';
+    testing.onload(() => {
+      testing.expectEqual('<html><head></head><body>a-page\n</body></html>', i.contentDocument.documentElement.outerHTML);
+    });
+  }
+</script>
+
 <script id=count>
-  testing.eventually(() => {
+  testing.onload(() => {
-    testing.expectEqual(8, window.length);
+    testing.expectEqual(9, window.length);
   });
 </script>

src/browser/tests/frames/post_message.html

@@ -17,7 +17,7 @@
     iframe.contentWindow.postMessage('ping', '*');
   });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('pong', reply.data);
     testing.expectEqual(testing.ORIGIN, reply.origin);
   });

src/browser/tests/frames/target.html

@@ -5,7 +5,7 @@
 <a id=l1 target=f1 href=support/page.html></a>
 <script id=anchor>
   $('#l1').click();
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('<html><head></head><body>a-page\n</body></html>', $('#frame1').contentDocument.documentElement.outerHTML);
   });
 </script>
@@ -21,7 +21,7 @@
     form.action = 'support/page.html';
     form.submit();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('<html><head></head><body>a-page\n</body></html>', frame2.contentDocument.documentElement.outerHTML);
     });
   }
@@ -35,7 +35,7 @@
 <script id=formtarget>
   {
     $('#submit1').click();
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('<html><head></head><body>a-page\n</body></html>', $('#f3').contentDocument.documentElement.outerHTML);
     });
   }

src/browser/tests/history.html

@@ -8,7 +8,7 @@
   // If support/history.html has a failed assertion, it'll log the error and
   // stop the script. If it succeeds, it'll set support_history_completed
   // which we can use here to assume everything passed.
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, window.support_history_completed);
     testing.expectEqual(true, window.support_history_popstateEventFired);
     testing.expectEqual({testInProgress: true }, window.support_history_popstateEventState);

src/browser/tests/intersection_observer/basic.html

@@ -14,7 +14,7 @@
 
     observer.observe(target);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(true, callbackCalled);
         testing.expectEqual(1, entries.length);
 
@@ -41,7 +41,7 @@
       count += 1;
     }).observe(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -56,7 +56,7 @@
     }).observe(div1);
 
     div2.appendChild(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }

src/browser/tests/intersection_observer/disconnect.html

@@ -12,7 +12,7 @@
 
     observer.observe(target);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, callCount);
 
         observer.disconnect();
@@ -22,7 +22,7 @@
         const observer2 = new IntersectionObserver(() => {});
         observer2.observe(target);
 
-        testing.eventually(() => {
+        testing.onload(() => {
             observer2.disconnect();
             testing.expectEqual(1, callCount);
         });

src/browser/tests/intersection_observer/multiple_targets.html

@@ -19,7 +19,7 @@
     observer.observe(target1);
     observer.observe(target2);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(2, entryCount);
         testing.expectTrue(seenTargets.has(target1));
         testing.expectTrue(seenTargets.has(target2));

src/browser/tests/intersection_observer/unobserve.html

@@ -20,7 +20,7 @@
     observer.unobserve(target1);
     observer.observe(target2);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         // Should only see target2, not target1
         testing.expectEqual(1, seenTargets.length);
         testing.expectEqual(target2, seenTargets[0]);

src/browser/tests/legacy/cssom/css_stylesheet.html

@@ -12,5 +12,5 @@
 
   let replaced = false;
   css.replace('body{}').then(() => replaced = true);
-  testing.eventually(() => testing.expectEqual(true, replaced));
+  testing.onload(() => testing.expectEqual(true, replaced));
 </script>

src/browser/tests/legacy/dom/animation.html

@@ -11,5 +11,5 @@
     cb.push('finished');
     cb.push(x == a1);
   });
-  testing.eventually(() => testing.expectEqual(['finished', true], cb));
+  testing.onload(() => testing.expectEqual(['finished', true], cb));
 </script>

src/browser/tests/legacy/dom/intersection_observer.html

@@ -11,7 +11,7 @@
       count += 1;
     }).observe(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -27,7 +27,7 @@
     }).observe(div1);
 
     div2.appendChild(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }
@@ -51,7 +51,7 @@
     observer.observe(div1);
     testing.expectEqual(0, count);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }
@@ -75,7 +75,7 @@
     testing.expectEqual(0, count);
 
     observer.unobserve(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -100,7 +100,7 @@
     testing.expectEqual(0, count);
     observer.disconnect();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -117,7 +117,7 @@
     document.body.appendChild(div1);
     new IntersectionObserver(entries => { entry = entries[0]; }).observe(div1);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(125, entry.boundingClientRect.x);
       testing.expectEqual(1, entry.intersectionRatio);
       testing.expectEqual(125, entry.intersectionRect.x);
@@ -150,7 +150,7 @@
     observer.observe(div);
     capture.push('post-observe');
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual([
         'pre-append',
         'post-append',

src/browser/tests/legacy/html/abort_controller.html

@@ -31,7 +31,7 @@
 
 <script id=timeout>
   var s3 = AbortSignal.timeout(10);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, s3.aborted);
     testing.expectEqual('TimeoutError', s3.reason);
     testing.expectError('Error: TimeoutError', () => {

src/browser/tests/legacy/html/history/history.html

@@ -28,7 +28,7 @@
         popstateEventState = event.state;
     });
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, popstateEventFired);
       testing.expectEqual(state, popstateEventState);
     })

src/browser/tests/legacy/html/history/history2.html

@@ -14,7 +14,7 @@
         popstateEventState = event.state;
     };
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, popstateEventFired);
       testing.expectEqual(state, popstateEventState);
     })

src/browser/tests/legacy/html/script/inline_defer.html

@@ -24,5 +24,5 @@
   // inline script should ignore defer and async attributes. If we don't do
   // this correctly, we'd end up in an infinite loop
   // https://github.com/lightpanda-io/browser/issues/1014
-  testing.eventually(() => testing.expectEqual(2, dyn1_loaded));
+  testing.onload(() => testing.expectEqual(2, dyn1_loaded));
 </script>

src/browser/tests/legacy/html/slot.html

@@ -94,7 +94,7 @@
     lp.appendChild(div);
     testing.expectEqual(slot, div.assignedSlot);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -113,7 +113,7 @@
 
     const div = $('#s2');
     div.removeAttribute('slot');
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -132,7 +132,7 @@
 
     const div = $('#s3');
     div.slot = 'other';
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -154,7 +154,7 @@
     div.slot = 'other';
     lp.appendChild(div);
     div.slot = 'slot-1'
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -172,7 +172,7 @@
     });
 
     $('#s5').remove();
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }

src/browser/tests/legacy/window/window.html

@@ -16,7 +16,7 @@
     start = timestamp;
   }
   requestAnimationFrame(step);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, start > 0)
   });
 
@@ -24,23 +24,23 @@
     start = 0;
   });
   cancelAnimationFrame(request_id);
-  testing.eventually(() => testing.expectEqual(true, start > 0));
+  testing.onload(() => testing.expectEqual(true, start > 0));
 </script>
 
 <script id=setTimeout>
   let longCall = false;
   window.setTimeout(() => {longCall = true}, 5001);
-  testing.eventually(() => testing.expectEqual(false, longCall));
+  testing.onload(() => testing.expectEqual(false, longCall));
 
   let wst1 = 0;
   window.setTimeout(() => {wst1 += 1}, 1);
-  testing.eventually(() => testing.expectEqual(1, wst1));
+  testing.onload(() => testing.expectEqual(1, wst1));
 
   let wst2 = 1;
   window.setTimeout((a, b) => {
     wst2 = a + b;
   }, 1, 2, 3);
-  testing.eventually(() => testing.expectEqual(5, wst2));
+  testing.onload(() => testing.expectEqual(5, wst2));
 </script>
 
 <script id=eventTarget>
@@ -70,7 +70,7 @@
 <script id=queueMicroTask>
   var qm = false;
   window.queueMicrotask(() => {qm = true });
-  testing.eventually(() => testing.expectEqual(true, qm));
+  testing.onload(() => testing.expectEqual(true, qm));
 </script>
 
 <script id=DOMContentLoaded>
@@ -79,7 +79,7 @@
   window.addEventListener('DOMContentLoaded', (e) => {
     dcl = e.target == document;
   });
-  testing.eventually(() => testing.expectEqual(true, dcl));
+  testing.onload(() => testing.expectEqual(true, dcl));
 </script>
 
 <script id=window.onload>
@@ -97,7 +97,7 @@
   window.onload = callback;
   testing.expectEqual(callback, window.onload);
 
-  testing.eventually(() => testing.expectEqual(true, isDocumentTarget));
+  testing.onload(() => testing.expectEqual(true, isDocumentTarget));
 </script>
 
 <script id=reportError>

src/browser/tests/mcp_wait_for_selector.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html>
+<body>
+    <div id="existing">Already here</div>
+    <script>
+        setTimeout(function() {
+            var el = document.createElement("div");
+            el.id = "delayed";
+            el.textContent = "Appeared after delay";
+            document.body.appendChild(el);
+        }, 20);
+    </script>
+</body>
+</html>

src/browser/tests/node/append_child.html

@@ -28,3 +28,40 @@
   d1.appendChild(p2);
   assertChildren(['p1', 'p2'], d1);
 </script>
+
+<div id=d3></div>
+<script id=appendChild_fragment_mutation>
+  // Test that appendChild with DocumentFragment handles synchronous callbacks
+  // (like custom element connectedCallback) that modify the fragment during iteration.
+  // This reproduces a bug where the iterator captures "next" node pointers
+  // before processing, but callbacks can remove those nodes from the fragment.
+  const d3 = $('#d3');
+  const fragment = document.createDocumentFragment();
+
+  // Create custom element whose connectedCallback modifies the fragment
+  let bElement = null;
+  class ModifyingElement extends HTMLElement {
+    connectedCallback() {
+      // When this element is connected, remove 'b' from the fragment
+      if (bElement && bElement.parentNode === fragment) {
+        fragment.removeChild(bElement);
+      }
+    }
+  }
+  customElements.define('modifying-element', ModifyingElement);
+
+  const a = document.createElement('modifying-element');
+  a.id = 'a';
+  const b = document.createElement('span');
+  b.id = 'b';
+  bElement = b;
+  fragment.appendChild(a);
+  fragment.appendChild(b);
+
+  // This should not crash - appendChild should handle the modification gracefully
+  d3.appendChild(fragment);
+
+  // 'a' should be in d3, 'b' was removed by connectedCallback and is now detached
+  assertChildren(['a'], d3);
+  testing.expectEqual(null, b.parentNode);
+</script>

src/browser/tests/page/blob.html

@@ -12,7 +12,7 @@
     document.body.appendChild(iframe);
     iframe.src = blob_url;
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('Hello Blob', iframe.contentDocument.getElementById('test').textContent);
     });
   }
@@ -33,7 +33,7 @@
     document.body.appendChild(iframe2);
     iframe2.src = url2;
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('First', iframe1.contentDocument.body.textContent);
       testing.expectEqual('Second', iframe2.contentDocument.body.textContent);
     });

src/browser/tests/page/load_event.html

@@ -9,7 +9,7 @@
     call1 = true;
   });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(document, ex1.target);
     testing.expectEqual('DOMContentLoaded', ex1.type);
     testing.expectEqual(true, call1);

src/browser/tests/performance_observer/performance_observer.html

@@ -86,7 +86,7 @@
   // With buffered: true, existing marks should be delivered
   observer.observe({ type: "mark", buffered: true });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, receivedEntries !== null);
     testing.expectEqual(2, receivedEntries.length);
     testing.expectEqual("early1", receivedEntries[0].name);

src/browser/tests/selection.html

@@ -582,7 +582,7 @@
     document.removeEventListener('selectionchange', listener);
     textNode.textContent = "The quick brown fox";
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(14, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(document, lastEvent.target);

src/browser/tests/testing.js

@@ -52,10 +52,10 @@
     throw new Error('no error');
   }
 
-  function eventually(cb) {
+  function onload(cb) {
     const script_id = _currentScriptId();
     if (!script_id) {
-      throw new Error('testing.eventually called outside of a script');
+      throw new Error('testing.onload called outside of a script');
     }
     eventuallies.push({
       callback: cb,
@@ -110,7 +110,7 @@
     expectEqual: expectEqual,
     expectError: expectError,
     withError: withError,
-    eventually: eventually,
+    onload: onload,
     IS_TEST_RUNNER: IS_TEST_RUNNER,
     HOST: '127.0.0.1',
     ORIGIN: 'http://127.0.0.1:9582',

src/browser/tests/url.html

@@ -591,6 +591,35 @@
   testing.expectEqual('/new/path', url.pathname);
 }
 
+// Pathname setter must percent-encode spaces and special characters
+{
+  const url = new URL('http://a/');
+  url.pathname = 'c d';
+  testing.expectEqual('http://a/c%20d', url.href);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.pathname = '/path with spaces/file name';
+  testing.expectEqual('https://example.com/path%20with%20spaces/file%20name', url.href);
+  testing.expectEqual('/path%20with%20spaces/file%20name', url.pathname);
+}
+
+// Already-encoded sequences should not be double-encoded
+{
+  const url = new URL('https://example.com/path');
+  url.pathname = '/already%20encoded';
+  testing.expectEqual('https://example.com/already%20encoded', url.href);
+}
+
+// This is the exact check the URL polyfill uses to decide if native URL is sufficient
+{
+  const url = new URL('b', 'http://a');
+  url.pathname = 'c d';
+  testing.expectEqual('http://a/c%20d', url.href);
+  testing.expectEqual(true, !!url.searchParams);
+}
+
 {
   const url = new URL('https://example.com/path');
   url.search = '?a=b';
@@ -656,6 +685,20 @@
   testing.expectEqual('', url.hash);
 }
 
+{
+  const url = new URL('https://example.com/path');
+  url.hash = '#a b';
+  testing.expectEqual('https://example.com/path#a%20b', url.href);
+  testing.expectEqual('#a%20b', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.hash = 'a b';
+  testing.expectEqual('https://example.com/path#a%20b', url.href);
+  testing.expectEqual('#a%20b', url.hash);
+}
+
 {
   const url = new URL('https://example.com/path?a=b');
   url.search = '';
@@ -673,6 +716,20 @@
   testing.expectEqual(null, url.searchParams.get('a'));
 }
 
+{
+  const url = new URL('https://example.com/path?a=b');
+  const sp = url.searchParams;
+  testing.expectEqual('b', sp.get('a'));
+  url.search = 'c=d b';
+
+  testing.expectEqual('d b', url.searchParams.get('c'));
+  testing.expectEqual(null, url.searchParams.get('a'));
+
+  url.search = 'c d=d b';
+  testing.expectEqual('d b', url.searchParams.get('c d'));
+  testing.expectEqual(null, url.searchParams.get('c'));
+}
+
 {
   const url = new URL('https://example.com/path?a=b');
   const sp = url.searchParams;
@@ -798,3 +855,19 @@
   testing.expectEqual(true, url2.startsWith('blob:'));
 }
 </script>
+
+<script id="about:blank">
+  {
+    const url = new URL('about:blank');
+    testing.expectEqual('about:blank', url.href);
+    testing.expectEqual('null', url.origin);
+    testing.expectEqual('about:', url.protocol);
+    testing.expectEqual('blank', url.pathname);
+    testing.expectEqual('', url.username);
+    testing.expectEqual('', url.password);
+    testing.expectEqual('', url.host);
+    testing.expectEqual('', url.hostname);
+    testing.expectEqual('', url.port);
+    testing.expectEqual('', url.search);
+  }
+</script>

src/browser/tests/window/body_onload1.html

@@ -10,7 +10,7 @@
     testing.expectEqual(window, e.currentTarget);
   }
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, called);
   });
 </script>

src/browser/tests/window/body_onload2.html

@@ -7,7 +7,7 @@
   // Verify: handler fires, "event" parameter is a proper Event, and handler is a function.
   let loadEvent = null;
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual("function", typeof document.body.onload);
     testing.expectTrue(loadEvent instanceof Event);
     testing.expectEqual("load", loadEvent.type);

src/browser/tests/window/body_onload3.html

@@ -7,7 +7,7 @@
   // Verify: handler fires exactly once, and body.onload reflects to window.onload.
   let called = 0;
 
-  testing.eventually(() => {
+  testing.onload(() => {
     // The attribute handler should have fired exactly once.
     testing.expectEqual(1, called);
 

src/browser/tests/window/timers.html

@@ -17,7 +17,7 @@
   testing.expectEqual(true, timer1 != timer2);
 
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, set_interval1);
     testing.expectEqual(false, set_interval2);
   });
@@ -29,7 +29,7 @@
   window.setTimeout((a, b) => {
     wst2 = a + b;
   }, 1, 2, 3);
-  testing.eventually(() => testing.expectEqual(5, wst2));
+  testing.onload(() => testing.expectEqual(5, wst2));
 </script>
 
 <script id=invalid-timer-clear>

src/browser/tests/window/window.html

@@ -43,7 +43,7 @@
 
   // noop
   window.removeEventListener('load', fn);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, call1);
     testing.expectEqual(2, call2);
   });
@@ -285,6 +285,6 @@
       unhandledCalled += 1;
     });
     Promise.reject({x: 'Fail'});
-    testing.eventually(() => testing.expectEqual(2, unhandledCalled));
+    testing.onload(() => testing.expectEqual(2, unhandledCalled));
   }
 </script>

src/browser/webapi/CryptoKey.zig

@@ -0,0 +1,107 @@
+// Copyright (C) 2023-2026 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 crypto = @import("../../sys/libcrypto.zig");
+
+const js = @import("../js/js.zig");
+
+/// Represents a cryptographic key obtained from one of the SubtleCrypto methods
+/// generateKey(), deriveKey(), importKey(), or unwrapKey().
+const CryptoKey = @This();
+
+/// Algorithm being used.
+_type: Type,
+/// Whether the key is extractable.
+_extractable: bool,
+/// Bit flags of `usages`; see `Usages` type.
+_usages: u8,
+/// Raw bytes of key.
+_key: []const u8,
+/// Different algorithms may use different data structures;
+/// this union can be used for such situations. Active field is understood
+/// from `_type`.
+_vary: extern union {
+    /// Used by HMAC.
+    digest: *const crypto.EVP_MD,
+    /// Used by asymmetric algorithms (X25519, Ed25519).
+    pkey: *crypto.EVP_PKEY,
+},
+
+/// https://developer.mozilla.org/en-US/docs/Web/API/CryptoKeyPair
+pub const Pair = struct {
+    privateKey: *CryptoKey,
+    publicKey: *CryptoKey,
+};
+
+/// Key-creating functions expect this format.
+pub const KeyOrPair = union(enum) { key: *CryptoKey, pair: Pair };
+
+pub const Type = enum(u8) { hmac, rsa, x25519 };
+
+/// Changing the names of fields would affect bitmask creation.
+pub const Usages = struct {
+    // zig fmt: off
+    pub const encrypt    = 0x001;
+    pub const decrypt    = 0x002;
+    pub const sign       = 0x004;
+    pub const verify     = 0x008;
+    pub const deriveKey  = 0x010;
+    pub const deriveBits = 0x020;
+    pub const wrapKey    = 0x040;
+    pub const unwrapKey  = 0x080;
+    // zig fmt: on
+};
+
+pub inline fn canSign(self: *const CryptoKey) bool {
+    return self._usages & Usages.sign != 0;
+}
+
+pub inline fn canVerify(self: *const CryptoKey) bool {
+    return self._usages & Usages.verify != 0;
+}
+
+pub inline fn canDeriveBits(self: *const CryptoKey) bool {
+    return self._usages & Usages.deriveBits != 0;
+}
+
+pub inline fn canExportKey(self: *const CryptoKey) bool {
+    return self._extractable;
+}
+
+/// Only valid for HMAC.
+pub inline fn getDigest(self: *const CryptoKey) *const crypto.EVP_MD {
+    return self._vary.digest;
+}
+
+/// Only valid for asymmetric algorithms (X25519, Ed25519).
+pub inline fn getKeyObject(self: *const CryptoKey) *crypto.EVP_PKEY {
+    return self._vary.pkey;
+}
+
+pub const JsApi = struct {
+    pub const bridge = js.Bridge(CryptoKey);
+
+    pub const Meta = struct {
+        pub const name = "CryptoKey";
+
+        pub var class_id: bridge.ClassId = undefined;
+        pub const prototype_chain = bridge.prototypeChain();
+    };
+};

src/browser/webapi/Document.zig

@@ -548,35 +548,8 @@ pub fn prepend(self: *Document, nodes: []const Node.NodeOrText, page: *Page) !vo
 }
 
 pub fn replaceChildren(self: *Document, nodes: []const Node.NodeOrText, page: *Page) !void {
-    try validateDocumentNodes(self, nodes, true);
+    try validateDocumentNodes(self, nodes, false);
-
+    return self.asNode().replaceChildren(nodes, page);
-    page.domChanged();
-    const parent = self.asNode();
-
-    // Remove all existing children
-    var it = parent.childrenIterator();
-    while (it.next()) |child| {
-        page.removeNode(parent, child, .{ .will_be_reconnected = false });
-    }
-
-    // Append new children
-    const parent_is_connected = parent.isConnected();
-    for (nodes) |node_or_text| {
-        const child = try node_or_text.toNode(page);
-
-        // DocumentFragments are special - append all their children
-        if (child.is(Node.DocumentFragment)) |_| {
-            try page.appendAllChildren(child, parent);
-            continue;
-        }
-
-        var child_connected = false;
-        if (child._parent) |previous_parent| {
-            child_connected = child.isConnected();
-            page.removeNode(previous_parent, child, .{ .will_be_reconnected = parent_is_connected });
-        }
-        try page.appendNode(parent, child, .{ .child_already_connected = child_connected });
-    }
 }
 
 pub fn elementFromPoint(self: *Document, x: f64, y: f64, page: *Page) !?*Element {
@@ -591,7 +564,7 @@ pub fn elementFromPoint(self: *Document, x: f64, y: f64, page: *Page) !?*Element
     while (stack.items.len > 0) {
         const node = stack.pop() orelse break;
         if (node.is(Element)) |element| {
-            if (element.checkVisibility(page)) {
+            if (element.checkVisibilityCached(null, page)) {
                 const rect = element.getBoundingClientRectForVisible(page);
                 if (x >= rect.getLeft() and x <= rect.getRight() and y >= rect.getTop() and y <= rect.getBottom()) {
                     topmost = element;
@@ -717,9 +690,16 @@ pub fn write(self: *Document, text: []const []const u8, page: *Page) !void {
     }
 
     // Determine insertion point:
-    // - If _write_insertion_point is set, continue from there (subsequent write)
+    // - If _write_insertion_point is set and still parented correctly, continue from there
-    // - Otherwise, start after the script (first write)
+    // - Otherwise, start after the script (first write, or previous insertion point was removed)
-    var insert_after: ?*Node = self._write_insertion_point orelse script.asNode();
+    var insert_after: ?*Node = blk: {
+        if (self._write_insertion_point) |wip| {
+            if (wip._parent == parent) {
+                break :blk wip;
+            }
+        }
+        break :blk script.asNode();
+    };
 
     for (children_to_insert.items) |child| {
         // Clear parent pointer (child is currently parented to fragment/HTML wrapper)
@@ -896,6 +876,10 @@ fn validateDocumentNodes(self: *Document, nodes: []const Node.NodeOrText, compti
                                 if (has_doctype) {
                                     return error.HierarchyError;
                                 }
+                                if (has_element) {
+                                    // Doctype cannot be inserted if document already has an element
+                                    return error.HierarchyError;
+                                }
                                 has_doctype = true;
                             },
                             .cdata => |cd| switch (cd._type) {
@@ -918,6 +902,10 @@ fn validateDocumentNodes(self: *Document, nodes: []const Node.NodeOrText, compti
                             if (has_doctype) {
                                 return error.HierarchyError;
                             }
+                            if (has_element) {
+                                // Doctype cannot be inserted if document already has an element
+                                return error.HierarchyError;
+                            }
                             has_doctype = true;
                         },
                         .cdata => |cd| switch (cd._type) {

src/browser/webapi/DocumentFragment.zig

@@ -143,25 +143,7 @@ pub fn prepend(self: *DocumentFragment, nodes: []const Node.NodeOrText, page: *P
 }
 
 pub fn replaceChildren(self: *DocumentFragment, nodes: []const Node.NodeOrText, page: *Page) !void {
-    page.domChanged();
+    return self.asNode().replaceChildren(nodes, page);
-    var parent = self.asNode();
-
-    var it = parent.childrenIterator();
-    while (it.next()) |child| {
-        page.removeNode(parent, child, .{ .will_be_reconnected = false });
-    }
-
-    const parent_is_connected = parent.isConnected();
-    for (nodes) |node_or_text| {
-        const child = try node_or_text.toNode(page);
-
-        // If the new children has already a parent, remove from it.
-        if (child._parent) |p| {
-            page.removeNode(p, child, .{ .will_be_reconnected = true });
-        }
-
-        try page.appendNode(parent, child, .{ .child_already_connected = parent_is_connected });
-    }
 }
 
 pub fn getInnerHTML(self: *DocumentFragment, writer: *std.Io.Writer, page: *Page) !void {

src/browser/webapi/Element.zig

@@ -24,6 +24,7 @@ const String = @import("../../string.zig").String;
 
 const js = @import("../js/js.zig");
 const Page = @import("../Page.zig");
+const StyleManager = @import("../StyleManager.zig");
 const reflect = @import("../reflect.zig");
 
 const Node = @import("Node.zig");
@@ -572,6 +573,32 @@ pub fn hasAttributeSafe(self: *const Element, name: String) bool {
     return attributes.hasSafe(name);
 }
 
+pub fn isDisabled(self: *Element) bool {
+    if (self.getAttributeSafe(comptime .wrap("disabled")) != null) {
+        return true;
+    }
+
+    const element_node = self.asNode();
+    var current: ?*Node = element_node._parent;
+    while (current) |node| {
+        current = node._parent;
+        const ancestor = node.is(Element) orelse continue;
+
+        if (ancestor.getTag() == .fieldset and ancestor.getAttributeSafe(comptime .wrap("disabled")) != null) {
+            var child = ancestor.firstElementChild();
+            while (child) |c| {
+                if (c.getTag() == .legend) {
+                    if (c.asNode().contains(element_node)) return false;
+                    break;
+                }
+                child = c.nextElementSibling();
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
 pub fn hasAttributes(self: *const Element) bool {
     const attributes = self._attributes orelse return false;
     return attributes.isEmpty() == false;
@@ -784,24 +811,7 @@ pub fn getDataset(self: *Element, page: *Page) !*DOMStringMap {
 }
 
 pub fn replaceChildren(self: *Element, nodes: []const Node.NodeOrText, page: *Page) !void {
-    page.domChanged();
+    return self.asNode().replaceChildren(nodes, page);
-    var parent = self.asNode();
-
-    var it = parent.childrenIterator();
-    while (it.next()) |child| {
-        page.removeNode(parent, child, .{ .will_be_reconnected = false });
-    }
-
-    const parent_is_connected = parent.isConnected();
-    for (nodes) |node_or_text| {
-        var child_connected = false;
-        const child = try node_or_text.toNode(page);
-        if (child._parent) |previous_parent| {
-            child_connected = child.isConnected();
-            page.removeNode(previous_parent, child, .{ .will_be_reconnected = parent_is_connected });
-        }
-        try page.appendNode(parent, child, .{ .child_already_connected = child_connected });
-    }
 }
 
 pub fn replaceWith(self: *Element, nodes: []const Node.NodeOrText, page: *Page) !void {
@@ -1041,20 +1051,32 @@ pub fn parentElement(self: *Element) ?*Element {
     return self._proto.parentElement();
 }
 
-pub fn checkVisibility(self: *Element, page: *Page) bool {
+/// Cache for visibility checks - re-exported from StyleManager for convenience.
-    var current: ?*Element = self;
+pub const VisibilityCache = StyleManager.VisibilityCache;
 
-    while (current) |el| {
+/// Cache for pointer-events checks - re-exported from StyleManager for convenience.
-        if (el.getStyle(page)) |style| {
+pub const PointerEventsCache = StyleManager.PointerEventsCache;
-            const display = style.asCSSStyleDeclaration().getPropertyValue("display", page);
-            if (std.mem.eql(u8, display, "none")) {
-                return false;
-            }
-        }
-        current = el.parentElement();
-    }
 
-    return true;
+pub fn hasPointerEventsNone(self: *Element, cache: ?*PointerEventsCache, page: *Page) bool {
+    return page._style_manager.hasPointerEventsNone(self, cache);
+}
+
+pub fn checkVisibilityCached(self: *Element, cache: ?*VisibilityCache, page: *Page) bool {
+    return !page._style_manager.isHidden(self, cache, .{});
+}
+
+const CheckVisibilityOpts = struct {
+    checkOpacity: bool = false,
+    opacityProperty: bool = false,
+    checkVisibilityCSS: bool = false,
+    visibilityProperty: bool = false,
+};
+pub fn checkVisibility(self: *Element, opts_: ?CheckVisibilityOpts, page: *Page) bool {
+    const opts = opts_ orelse CheckVisibilityOpts{};
+    return !page._style_manager.isHidden(self, null, .{
+        .check_opacity = opts.checkOpacity or opts.opacityProperty,
+        .check_visibility = opts.visibilityProperty or opts.checkVisibilityCSS,
+    });
 }
 
 fn getElementDimensions(self: *Element, page: *Page) struct { width: f64, height: f64 } {
@@ -1091,7 +1113,7 @@ fn getElementDimensions(self: *Element, page: *Page) struct { width: f64, height
 }
 
 pub fn getClientWidth(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     const dims = self.getElementDimensions(page);
@@ -1099,7 +1121,7 @@ pub fn getClientWidth(self: *Element, page: *Page) f64 {
 }
 
 pub fn getClientHeight(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     const dims = self.getElementDimensions(page);
@@ -1107,7 +1129,7 @@ pub fn getClientHeight(self: *Element, page: *Page) f64 {
 }
 
 pub fn getBoundingClientRect(self: *Element, page: *Page) DOMRect {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return .{
             ._x = 0.0,
             ._y = 0.0,
@@ -1137,7 +1159,7 @@ pub fn getBoundingClientRectForVisible(self: *Element, page: *Page) DOMRect {
 }
 
 pub fn getClientRects(self: *Element, page: *Page) ![]DOMRect {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return &.{};
     }
     const rects = try page.call_arena.alloc(DOMRect, 1);
@@ -1182,7 +1204,7 @@ pub fn getScrollWidth(self: *Element, page: *Page) f64 {
 }
 
 pub fn getOffsetHeight(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     const dims = self.getElementDimensions(page);
@@ -1190,7 +1212,7 @@ pub fn getOffsetHeight(self: *Element, page: *Page) f64 {
 }
 
 pub fn getOffsetWidth(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     const dims = self.getElementDimensions(page);
@@ -1198,14 +1220,14 @@ pub fn getOffsetWidth(self: *Element, page: *Page) f64 {
 }
 
 pub fn getOffsetTop(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     return calculateDocumentPosition(self.asNode());
 }
 
 pub fn getOffsetLeft(self: *Element, page: *Page) f64 {
-    if (!self.checkVisibility(page)) {
+    if (!self.checkVisibilityCached(null, page)) {
         return 0.0;
     }
     return calculateSiblingPosition(self.asNode());

src/browser/webapi/Event.zig

@@ -76,6 +76,7 @@ pub const Type = union(enum) {
     pop_state_event: *@import("event/PopStateEvent.zig"),
     ui_event: *@import("event/UIEvent.zig"),
     promise_rejection_event: *@import("event/PromiseRejectionEvent.zig"),
+    submit_event: *@import("event/SubmitEvent.zig"),
 };
 
 pub const Options = struct {
@@ -174,6 +175,7 @@ pub fn is(self: *Event, comptime T: type) ?*T {
         .page_transition_event => |e| return if (T == @import("event/PageTransitionEvent.zig")) e else null,
         .pop_state_event => |e| return if (T == @import("event/PopStateEvent.zig")) e else null,
         .promise_rejection_event => |e| return if (T == @import("event/PromiseRejectionEvent.zig")) e else null,
+        .submit_event => |e| return if (T == @import("event/SubmitEvent.zig")) e else null,
         .ui_event => |e| {
             if (T == @import("event/UIEvent.zig")) {
                 return e;

src/browser/webapi/IntersectionObserver.zig

@@ -93,12 +93,12 @@ pub fn init(callback: js.Function.Temp, options: ?ObserverInit, page: *Page) !*I
 }
 
 pub fn deinit(self: *IntersectionObserver, shutdown: bool, session: *Session) void {
-    if (shutdown) {
+    self._callback.release();
-        self._callback.release();
+    if ((comptime IS_DEBUG) and !shutdown) {
-        session.releaseArena(self._arena);
+        std.debug.assert(self._observing.items.len == 0);
-    } else if (comptime IS_DEBUG) {
-        std.debug.assert(false);
     }
+
+    session.releaseArena(self._arena);
 }
 
 pub fn observe(self: *IntersectionObserver, target: *Element, page: *Page) !void {
@@ -111,6 +111,7 @@ pub fn observe(self: *IntersectionObserver, target: *Element, page: *Page) !void
 
     // Register with page if this is our first observation
     if (self._observing.items.len == 0) {
+        page.js.strongRef(self);
         try page.registerIntersectionObserver(self);
     }
 
@@ -145,18 +146,22 @@ pub fn unobserve(self: *IntersectionObserver, target: *Element, page: *Page) voi
             break;
         }
     }
+
+    if (self._observing.items.len == 0) {
+        page.js.safeWeakRef(self);
+    }
 }
 
 pub fn disconnect(self: *IntersectionObserver, page: *Page) void {
+    page.unregisterIntersectionObserver(self);
+    self._observing.clearRetainingCapacity();
     self._previous_states.clearRetainingCapacity();
 
     for (self._pending_entries.items) |entry| {
         entry.deinit(false, page._session);
     }
     self._pending_entries.clearRetainingCapacity();
-
+    page.js.safeWeakRef(self);
-    self._observing.clearRetainingCapacity();
-    page.unregisterIntersectionObserver(self);
 }
 
 pub fn takeRecords(self: *IntersectionObserver, page: *Page) ![]*IntersectionObserverEntry {
@@ -358,6 +363,7 @@ pub const JsApi = struct {
         pub const name = "IntersectionObserver";
         pub const prototype_chain = bridge.prototypeChain();
         pub var class_id: bridge.ClassId = undefined;
+        pub const weak = true;
         pub const finalizer = bridge.finalizer(IntersectionObserver.deinit);
     };
 

src/browser/webapi/MutationObserver.zig

@@ -86,12 +86,12 @@ pub fn init(callback: js.Function.Temp, page: *Page) !*MutationObserver {
 }
 
 pub fn deinit(self: *MutationObserver, shutdown: bool, session: *Session) void {
-    if (shutdown) {
+    self._callback.release();
-        self._callback.release();
+    if ((comptime IS_DEBUG) and !shutdown) {
-        session.releaseArena(self._arena);
+        std.debug.assert(self._observing.items.len == 0);
-    } else if (comptime IS_DEBUG) {
-        std.debug.assert(false);
     }
+
+    session.releaseArena(self._arena);
 }
 
 pub fn observe(self: *MutationObserver, target: *Node, options: ObserveOptions, page: *Page) !void {
@@ -158,6 +158,7 @@ pub fn observe(self: *MutationObserver, target: *Node, options: ObserveOptions,
 
     // Register with page if this is our first observation
     if (self._observing.items.len == 0) {
+        page.js.strongRef(self);
         try page.registerMutationObserver(self);
     }
 
@@ -168,13 +169,13 @@ pub fn observe(self: *MutationObserver, target: *Node, options: ObserveOptions,
 }
 
 pub fn disconnect(self: *MutationObserver, page: *Page) void {
+    page.unregisterMutationObserver(self);
+    self._observing.clearRetainingCapacity();
     for (self._pending_records.items) |record| {
         record.deinit(false, page._session);
     }
     self._pending_records.clearRetainingCapacity();
-
+    page.js.safeWeakRef(self);
-    self._observing.clearRetainingCapacity();
-    page.unregisterMutationObserver(self);
 }
 
 pub fn takeRecords(self: *MutationObserver, page: *Page) ![]*MutationRecord {
@@ -440,6 +441,7 @@ pub const JsApi = struct {
         pub const name = "MutationObserver";
         pub const prototype_chain = bridge.prototypeChain();
         pub var class_id: bridge.ClassId = undefined;
+        pub const weak = true;
         pub const finalizer = bridge.finalizer(MutationObserver.deinit);
     };
 

src/browser/webapi/Node.zig

@@ -1005,6 +1005,49 @@ pub fn getElementsByClassName(self: *Node, class_name: []const u8, page: *Page)
     return collections.NodeLive(.class_name).init(self, class_names.items, page);
 }
 
+/// Shared implementation of replaceChildren for Element, Document, and DocumentFragment.
+/// Validates all nodes, removes existing children, then appends new children.
+pub fn replaceChildren(self: *Node, nodes: []const NodeOrText, page: *Page) !void {
+    // First pass: validate all nodes and collect them
+    // We need to collect because DocumentFragments contribute their children, not themselves
+    var children_to_add: std.ArrayList(*Node) = .empty;
+
+    for (nodes) |node_or_text| {
+        const child = try node_or_text.toNode(page);
+
+        // DocumentFragments contribute their children, not themselves
+        if (child.is(DocumentFragment)) |frag| {
+            var frag_it = frag.asNode().childrenIterator();
+            while (frag_it.next()) |frag_child| {
+                try validateNodeInsertion(self, frag_child);
+                try children_to_add.append(page.call_arena, frag_child);
+            }
+        } else {
+            try validateNodeInsertion(self, child);
+            try children_to_add.append(page.call_arena, child);
+        }
+    }
+
+    page.domChanged();
+
+    // Remove all existing children
+    var it = self.childrenIterator();
+    while (it.next()) |child| {
+        page.removeNode(self, child, .{ .will_be_reconnected = false });
+    }
+
+    // Append new children
+    const parent_is_connected = self.isConnected();
+    for (children_to_add.items) |child| {
+        var child_connected = false;
+        if (child._parent) |previous_parent| {
+            child_connected = child.isConnected();
+            page.removeNode(previous_parent, child, .{ .will_be_reconnected = parent_is_connected });
+        }
+        try page.appendNode(self, child, .{ .child_already_connected = child_connected });
+    }
+}
+
 // Writes a JSON representation of the node and its children
 pub fn jsonStringify(self: *const Node, writer: *std.json.Stringify) !void {
     // stupid json api requires this to be const,

src/browser/webapi/SubtleCrypto.zig

@@ -1,4 +1,4 @@
-// Copyright (C) 2023-2025  Lightpanda (Selecy SAS)
+// Copyright (C) 2023-2026 Lightpanda (Selecy SAS)
 //
 // Francis Bouvier <francis@lightpanda.io>
 // Pierre Tachoire <pierre@lightpanda.io>
@@ -19,16 +19,16 @@
 const std = @import("std");
 const lp = @import("lightpanda");
 const log = @import("../../log.zig");
-
+const crypto = @import("../../sys/libcrypto.zig");
-const crypto = @import("../../crypto.zig");
-const DOMException = @import("DOMException.zig");
 
 const Page = @import("../Page.zig");
 const js = @import("../js/js.zig");
 
-pub fn registerTypes() []const type {
+const CryptoKey = @import("CryptoKey.zig");
-    return &.{ SubtleCrypto, CryptoKey };
+
-}
+const algorithm = @import("crypto/algorithm.zig");
+const HMAC = @import("crypto/HMAC.zig");
+const X25519 = @import("crypto/X25519.zig");
 
 /// The SubtleCrypto interface of the Web Crypto API provides a number of low-level
 /// cryptographic functions.
@@ -38,69 +38,36 @@ const SubtleCrypto = @This();
 /// Don't optimize away the type.
 _pad: bool = false,
 
-const Algorithm = union(enum) {
-    /// For RSASSA-PKCS1-v1_5, RSA-PSS, or RSA-OAEP: pass an RsaHashedKeyGenParams object.
-    rsa_hashed_key_gen: RsaHashedKeyGen,
-    /// For HMAC: pass an HmacKeyGenParams object.
-    hmac_key_gen: HmacKeyGen,
-    /// Can be Ed25519 or X25519.
-    name: []const u8,
-    /// Can be Ed25519 or X25519.
-    object: struct { name: []const u8 },
-
-    /// https://developer.mozilla.org/en-US/docs/Web/API/RsaHashedKeyGenParams
-    const RsaHashedKeyGen = struct {
-        name: []const u8,
-        /// This should be at least 2048.
-        /// Some organizations are now recommending that it should be 4096.
-        modulusLength: u32,
-        publicExponent: js.TypedArray(u8),
-        hash: union(enum) {
-            string: []const u8,
-            object: struct { name: []const u8 },
-        },
-    };
-
-    /// https://developer.mozilla.org/en-US/docs/Web/API/HmacKeyGenParams
-    const HmacKeyGen = struct {
-        /// Always HMAC.
-        name: []const u8,
-        /// Its also possible to pass this in an object.
-        hash: union(enum) {
-            string: []const u8,
-            object: struct { name: []const u8 },
-        },
-        /// If omitted, default is the block size of the chosen hash function.
-        length: ?usize,
-    };
-    /// Alias.
-    const HmacImport = HmacKeyGen;
-
-    const EcdhKeyDeriveParams = struct {
-        /// Can be Ed25519 or X25519.
-        name: []const u8,
-        public: *const CryptoKey,
-    };
-
-    /// Algorithm for deriveBits() and deriveKey().
-    const DeriveBits = union(enum) {
-        ecdh_or_x25519: EcdhKeyDeriveParams,
-    };
-};
-
 /// Generate a new key (for symmetric algorithms) or key pair (for public-key algorithms).
 pub fn generateKey(
     _: *const SubtleCrypto,
-    algorithm: Algorithm,
+    algo: algorithm.Init,
     extractable: bool,
     key_usages: []const []const u8,
     page: *Page,
 ) !js.Promise {
-    const key_or_pair = CryptoKey.init(algorithm, extractable, key_usages, page) catch {
+    switch (algo) {
-        return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.SyntaxError } });
+        .hmac_key_gen => |params| return HMAC.init(params, extractable, key_usages, page),
-    };
+        .name => |name| {
+            if (std.mem.eql(u8, "X25519", name)) {
+                return X25519.init(extractable, key_usages, page);
+            }
 
-    return page.js.local.?.resolvePromise(key_or_pair);
+            log.warn(.not_implemented, "generateKey", .{ .name = name });
+        },
+        .object => |object| {
+            // Ditto.
+            const name = object.name;
+            if (std.mem.eql(u8, "X25519", name)) {
+                return X25519.init(extractable, key_usages, page);
+            }
+
+            log.warn(.not_implemented, "generateKey", .{ .name = name });
+        },
+        else => log.warn(.not_implemented, "generateKey", .{}),
+    }
+
+    return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.SyntaxError } });
 }
 
 /// Exports a key: that is, it takes as input a CryptoKey object and gives you
@@ -133,16 +100,23 @@ pub fn exportKey(
 /// Derive a secret key from a master key.
 pub fn deriveBits(
     _: *const SubtleCrypto,
-    algorithm: Algorithm.DeriveBits,
+    algo: algorithm.Derive,
     base_key: *const CryptoKey, // Private key.
     length: usize,
     page: *Page,
 ) !js.Promise {
-    return switch (algorithm) {
+    return switch (algo) {
-        .ecdh_or_x25519 => |p| {
+        .ecdh_or_x25519 => |params| {
-            const name = p.name;
+            const name = params.name;
             if (std.mem.eql(u8, name, "X25519")) {
-                return page.js.local.?.resolvePromise(base_key.deriveBitsX25519(p.public, length, page));
+                const result = X25519.deriveBits(base_key, params.public, length, page) catch |err| switch (err) {
+                    error.InvalidAccessError => return page.js.local.?.rejectPromise(.{
+                        .dom_exception = .{ .err = error.InvalidAccessError },
+                    }),
+                    else => return err,
+                };
+
+                return page.js.local.?.resolvePromise(result);
             }
 
             if (std.mem.eql(u8, name, "ECDH")) {
@@ -154,48 +128,18 @@ pub fn deriveBits(
     };
 }
 
-const SignatureAlgorithm = union(enum) {
-    string: []const u8,
-    object: struct { name: []const u8 },
-
-    pub fn isHMAC(self: SignatureAlgorithm) bool {
-        const name = switch (self) {
-            .string => |string| string,
-            .object => |object| object.name,
-        };
-
-        if (name.len < 4) return false;
-        const hmac: u32 = @bitCast([4]u8{ 'H', 'M', 'A', 'C' });
-        return @as(u32, @bitCast(name[0..4].*)) == hmac;
-    }
-};
-
 /// Generate a digital signature.
 pub fn sign(
     _: *const SubtleCrypto,
-    /// This can either be provided as string or object.
-    /// We can't use the `Algorithm` type defined before though since there
-    /// are couple of changes between the two.
     /// https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/sign#algorithm
-    algorithm: SignatureAlgorithm,
+    algo: algorithm.Sign,
     key: *CryptoKey,
     data: []const u8, // ArrayBuffer.
     page: *Page,
 ) !js.Promise {
     return switch (key._type) {
-        .hmac => {
+        // Call sign for HMAC.
-            // Verify algorithm.
+        .hmac => return HMAC.sign(algo, key, data, page),
-            if (!algorithm.isHMAC()) {
-                return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.InvalidAccessError } });
-            }
-
-            // Call sign for HMAC.
-            const result = key.signHMAC(data, page) catch {
-                return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.InvalidAccessError } });
-            };
-
-            return page.js.local.?.resolvePromise(result);
-        },
         else => {
             log.warn(.not_implemented, "SubtleCrypto.sign", .{ .key_type = key._type });
             return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.InvalidAccessError } });
@@ -206,452 +150,43 @@ pub fn sign(
 /// Verify a digital signature.
 pub fn verify(
     _: *const SubtleCrypto,
-    algorithm: SignatureAlgorithm,
+    algo: algorithm.Sign,
     key: *const CryptoKey,
     signature: []const u8, // ArrayBuffer.
     data: []const u8, // ArrayBuffer.
     page: *Page,
 ) !js.Promise {
-    if (!algorithm.isHMAC()) {
+    if (!algo.isHMAC()) {
         return page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.InvalidAccessError } });
     }
 
     return switch (key._type) {
-        .hmac => key.verifyHMAC(signature, data, page),
+        .hmac => HMAC.verify(key, signature, data, page),
         else => page.js.local.?.rejectPromise(.{ .dom_exception = .{ .err = error.InvalidAccessError } }),
     };
 }
 
-pub fn digest(_: *const SubtleCrypto, algorithm: []const u8, data: js.TypedArray(u8), page: *Page) !js.Promise {
+/// Generates a digest of the given data, using the specified hash function.
+pub fn digest(_: *const SubtleCrypto, algo: []const u8, data: js.TypedArray(u8), page: *Page) !js.Promise {
     const local = page.js.local.?;
-    if (algorithm.len > 10) {
+
+    if (algo.len > 10) {
         return local.rejectPromise(.{ .dom_exception = .{ .err = error.NotSupported } });
     }
-    const normalized = std.ascii.lowerString(&page.buf, algorithm);
-    if (std.mem.eql(u8, normalized, "sha-1")) {
-        const Sha1 = std.crypto.hash.Sha1;
-        Sha1.hash(data.values, page.buf[0..Sha1.digest_length], .{});
-        return local.resolvePromise(js.ArrayBuffer{ .values = page.buf[0..Sha1.digest_length] });
-    }
-    if (std.mem.eql(u8, normalized, "sha-256")) {
-        const Sha256 = std.crypto.hash.sha2.Sha256;
-        Sha256.hash(data.values, page.buf[0..Sha256.digest_length], .{});
-        return local.resolvePromise(js.ArrayBuffer{ .values = page.buf[0..Sha256.digest_length] });
-    }
-    if (std.mem.eql(u8, normalized, "sha-384")) {
-        const Sha384 = std.crypto.hash.sha2.Sha384;
-        Sha384.hash(data.values, page.buf[0..Sha384.digest_length], .{});
-        return local.resolvePromise(js.ArrayBuffer{ .values = page.buf[0..Sha384.digest_length] });
-    }
-    if (std.mem.eql(u8, normalized, "sha-512")) {
-        const Sha512 = std.crypto.hash.sha2.Sha512;
-        Sha512.hash(data.values, page.buf[0..Sha512.digest_length], .{});
-        return local.resolvePromise(js.ArrayBuffer{ .values = page.buf[0..Sha512.digest_length] });
-    }
-    return local.rejectPromise(.{ .dom_exception = .{ .err = error.NotSupported } });
-}
 
-/// Returns the desired digest by its name.
+    const normalized = std.ascii.upperString(&page.buf, algo);
-fn findDigest(name: []const u8) error{Invalid}!*const crypto.EVP_MD {
+    const digest_type = crypto.findDigest(normalized) catch {
-    if (std.mem.eql(u8, "SHA-256", name)) {
+        return local.rejectPromise(.{ .dom_exception = .{ .err = error.NotSupported } });
-        return crypto.EVP_sha256();
-    }
-
-    if (std.mem.eql(u8, "SHA-384", name)) {
-        return crypto.EVP_sha384();
-    }
-
-    if (std.mem.eql(u8, "SHA-512", name)) {
-        return crypto.EVP_sha512();
-    }
-
-    if (std.mem.eql(u8, "SHA-1", name)) {
-        return crypto.EVP_sha1();
-    }
-
-    return error.Invalid;
-}
-
-const KeyOrPair = union(enum) { key: *CryptoKey, pair: CryptoKeyPair };
-
-/// https://developer.mozilla.org/en-US/docs/Web/API/CryptoKeyPair
-const CryptoKeyPair = struct {
-    privateKey: *CryptoKey,
-    publicKey: *CryptoKey,
-};
-
-/// Represents a cryptographic key obtained from one of the SubtleCrypto methods
-/// generateKey(), deriveKey(), importKey(), or unwrapKey().
-pub const CryptoKey = struct {
-    /// Algorithm being used.
-    _type: Type,
-    /// Whether the key is extractable.
-    _extractable: bool,
-    /// Bit flags of `usages`; see `Usages` type.
-    _usages: u8,
-    /// Raw bytes of key.
-    _key: []const u8,
-    /// Different algorithms may use different data structures;
-    /// this union can be used for such situations. Active field is understood
-    /// from `_type`.
-    _vary: extern union {
-        /// Used by HMAC.
-        digest: *const crypto.EVP_MD,
-        /// Used by asymmetric algorithms (X25519, Ed25519).
-        pkey: *crypto.EVP_PKEY,
-    },
-
-    pub const Type = enum(u8) { hmac, rsa, x25519 };
-
-    /// Changing the names of fields would affect bitmask creation.
-    pub const Usages = struct {
-        // zig fmt: off
-        pub const encrypt    = 0x001;
-        pub const decrypt    = 0x002;
-        pub const sign       = 0x004;
-        pub const verify     = 0x008;
-        pub const deriveKey  = 0x010;
-        pub const deriveBits = 0x020;
-        pub const wrapKey    = 0x040;
-        pub const unwrapKey  = 0x080;
-        // zig fmt: on
     };
 
-    pub fn init(
+    const bytes = data.values;
-        algorithm: Algorithm,
+    const out = page.buf[0..crypto.EVP_MAX_MD_SIZE];
-        extractable: bool,
+    var out_size: c_uint = 0;
-        key_usages: []const []const u8,
+    const result = crypto.EVP_Digest(bytes.ptr, bytes.len, out, &out_size, digest_type, null);
-        page: *Page,
+    lp.assert(result == 1, "SubtleCrypto.digest", .{ .algo = algo });
-    ) !KeyOrPair {
-        return switch (algorithm) {
-            .hmac_key_gen => |hmac| initHMAC(hmac, extractable, key_usages, page),
-            .name => |name| {
-                if (std.mem.eql(u8, "X25519", name)) {
-                    return initX25519(extractable, key_usages, page);
-                }
-                log.warn(.not_implemented, "CryptoKey.init", .{ .name = name });
-                return error.NotSupported;
-            },
-            .object => |object| {
-                // Ditto.
-                const name = object.name;
-                if (std.mem.eql(u8, "X25519", name)) {
-                    return initX25519(extractable, key_usages, page);
-                }
-                log.warn(.not_implemented, "CryptoKey.init", .{ .name = name });
-                return error.NotSupported;
-            },
-            else => {
-                log.warn(.not_implemented, "CryptoKey.init", .{ .algorithm = algorithm });
-                return error.NotSupported;
-            },
-        };
-    }
 
-    inline fn canSign(self: *const CryptoKey) bool {
+    return local.resolvePromise(js.ArrayBuffer{ .values = out[0..out_size] });
-        return self._usages & Usages.sign != 0;
+}
-    }
-
-    inline fn canVerify(self: *const CryptoKey) bool {
-        return self._usages & Usages.verify != 0;
-    }
-
-    inline fn canDeriveBits(self: *const CryptoKey) bool {
-        return self._usages & Usages.deriveBits != 0;
-    }
-
-    inline fn canExportKey(self: *const CryptoKey) bool {
-        return self._extractable;
-    }
-
-    /// Only valid for HMAC.
-    inline fn getDigest(self: *const CryptoKey) *const crypto.EVP_MD {
-        return self._vary.digest;
-    }
-
-    /// Only valid for asymmetric algorithms (X25519, Ed25519).
-    inline fn getKeyObject(self: *const CryptoKey) *crypto.EVP_PKEY {
-        return self._vary.pkey;
-    }
-
-    // HMAC.
-
-    fn initHMAC(
-        algorithm: Algorithm.HmacKeyGen,
-        extractable: bool,
-        key_usages: []const []const u8,
-        page: *Page,
-    ) !KeyOrPair {
-        const hash = switch (algorithm.hash) {
-            .string => |str| str,
-            .object => |obj| obj.name,
-        };
-        // Find digest.
-        const d = try findDigest(hash);
-
-        // We need at least a single usage.
-        if (key_usages.len == 0) {
-            return error.SyntaxError;
-        }
-        // Calculate usages mask.
-        const decls = @typeInfo(Usages).@"struct".decls;
-        var usages_mask: u8 = 0;
-        iter_usages: for (key_usages) |usage| {
-            inline for (decls) |decl| {
-                if (std.mem.eql(u8, decl.name, usage)) {
-                    usages_mask |= @field(Usages, decl.name);
-                    continue :iter_usages;
-                }
-            }
-            // Unknown usage if got here.
-            return error.SyntaxError;
-        }
-
-        const block_size: usize = blk: {
-            // Caller provides this in bits, not bytes.
-            if (algorithm.length) |length| {
-                break :blk length / 8;
-            }
-            // Prefer block size of the hash function instead.
-            break :blk crypto.EVP_MD_block_size(d);
-        };
-
-        const key = try page.arena.alloc(u8, block_size);
-        errdefer page.arena.free(key);
-
-        // HMAC is simply CSPRNG.
-        const res = crypto.RAND_bytes(key.ptr, key.len);
-        lp.assert(res == 1, "SubtleCrypto.initHMAC", .{ .res = res });
-
-        const crypto_key = try page._factory.create(CryptoKey{
-            ._type = .hmac,
-            ._extractable = extractable,
-            ._usages = usages_mask,
-            ._key = key,
-            ._vary = .{ .digest = d },
-        });
-
-        return .{ .key = crypto_key };
-    }
-
-    fn signHMAC(self: *const CryptoKey, data: []const u8, page: *Page) !js.ArrayBuffer {
-        if (!self.canSign()) {
-            return error.InvalidAccessError;
-        }
-
-        const buffer = try page.call_arena.alloc(u8, crypto.EVP_MD_size(self.getDigest()));
-        errdefer page.call_arena.free(buffer);
-        var out_len: u32 = 0;
-        // Try to sign.
-        const signed = crypto.HMAC(
-            self.getDigest(),
-            @ptrCast(self._key.ptr),
-            self._key.len,
-            data.ptr,
-            data.len,
-            buffer.ptr,
-            &out_len,
-        );
-
-        if (signed != null) {
-            return js.ArrayBuffer{ .values = buffer[0..out_len] };
-        }
-
-        // Not DOM exception, failed on our side.
-        return error.Invalid;
-    }
-
-    fn verifyHMAC(
-        self: *const CryptoKey,
-        signature: []const u8,
-        data: []const u8,
-        page: *Page,
-    ) !js.Promise {
-        if (!self.canVerify()) {
-            return error.InvalidAccessError;
-        }
-
-        var buffer: [crypto.EVP_MAX_MD_BLOCK_SIZE]u8 = undefined;
-        var out_len: u32 = 0;
-        // Try to sign.
-        const signed = crypto.HMAC(
-            self.getDigest(),
-            @ptrCast(self._key.ptr),
-            self._key.len,
-            data.ptr,
-            data.len,
-            &buffer,
-            &out_len,
-        );
-
-        if (signed != null) {
-            // CRYPTO_memcmp compare in constant time so prohibits time-based attacks.
-            const res = crypto.CRYPTO_memcmp(signed, @ptrCast(signature.ptr), signature.len);
-            return page.js.local.?.resolvePromise(res == 0);
-        }
-
-        return page.js.local.?.resolvePromise(false);
-    }
-
-    // X25519.
-
-    /// Create a pair of X25519.
-    fn initX25519(
-        extractable: bool,
-        key_usages: []const []const u8,
-        page: *Page,
-    ) !KeyOrPair {
-        // This code has too many allocations here and there, might be nice to
-        // gather them together with a single alloc call. Not sure if factory
-        // pattern is suitable for it though.
-
-        // Calculate usages; only matters for private key.
-        // Only deriveKey() and deriveBits() be used for X25519.
-        if (key_usages.len == 0) {
-            return error.SyntaxError;
-        }
-        var mask: u8 = 0;
-        iter_usages: for (key_usages) |usage| {
-            inline for ([_][]const u8{ "deriveKey", "deriveBits" }) |name| {
-                if (std.mem.eql(u8, name, usage)) {
-                    mask |= @field(Usages, name);
-                    continue :iter_usages;
-                }
-            }
-            // Unknown usage if got here.
-            return error.SyntaxError;
-        }
-
-        const public_value = try page.arena.alloc(u8, crypto.X25519_PUBLIC_VALUE_LEN);
-        errdefer page.arena.free(public_value);
-
-        const private_key = try page.arena.alloc(u8, crypto.X25519_PRIVATE_KEY_LEN);
-        errdefer page.arena.free(private_key);
-
-        // There's no info about whether this can fail; so I assume it cannot.
-        crypto.X25519_keypair(@ptrCast(public_value), @ptrCast(private_key));
-
-        // Create EVP_PKEY for public key.
-        // Seems we can use `EVP_PKEY_from_raw_private_key` for this, Chrome
-        // prefer not to, yet BoringSSL added it and recommends instead of what
-        // we're doing currently.
-        const public_pkey = crypto.EVP_PKEY_new_raw_public_key(
-            crypto.EVP_PKEY_X25519,
-            null,
-            public_value.ptr,
-            public_value.len,
-        );
-        if (public_pkey == null) {
-            return error.OutOfMemory;
-        }
-
-        // Create EVP_PKEY for private key.
-        // Seems we can use `EVP_PKEY_from_raw_private_key` for this, Chrome
-        // prefer not to, yet BoringSSL added it and recommends instead of what
-        // we're doing currently.
-        const private_pkey = crypto.EVP_PKEY_new_raw_private_key(
-            crypto.EVP_PKEY_X25519,
-            null,
-            private_key.ptr,
-            private_key.len,
-        );
-        if (private_pkey == null) {
-            return error.OutOfMemory;
-        }
-
-        const private = try page._factory.create(CryptoKey{
-            ._type = .x25519,
-            ._extractable = extractable,
-            ._usages = mask,
-            ._key = private_key,
-            ._vary = .{ .pkey = private_pkey.? },
-        });
-        errdefer page._factory.destroy(private);
-
-        const public = try page._factory.create(CryptoKey{
-            ._type = .x25519,
-            // Public keys are always extractable.
-            ._extractable = true,
-            // Always empty for public key.
-            ._usages = 0,
-            ._key = public_value,
-            ._vary = .{ .pkey = public_pkey.? },
-        });
-        errdefer page._factory.destroy(public);
-
-        return .{ .pair = .{ .privateKey = private, .publicKey = public } };
-    }
-
-    fn deriveBitsX25519(
-        private: *const CryptoKey,
-        public: *const CryptoKey,
-        length_in_bits: usize,
-        page: *Page,
-    ) !js.ArrayBuffer {
-        if (!private.canDeriveBits()) {
-            return error.InvalidAccessError;
-        }
-
-        const maybe_ctx = crypto.EVP_PKEY_CTX_new(private.getKeyObject(), null);
-        if (maybe_ctx) |ctx| {
-            // Context is valid, free it on failure.
-            errdefer crypto.EVP_PKEY_CTX_free(ctx);
-
-            // Init derive operation and set public key as peer.
-            if (crypto.EVP_PKEY_derive_init(ctx) != 1 or
-                crypto.EVP_PKEY_derive_set_peer(ctx, public.getKeyObject()) != 1)
-            {
-                // Failed on our end.
-                return error.Internal;
-            }
-
-            const derived_key = try page.call_arena.alloc(u8, 32);
-            errdefer page.call_arena.free(derived_key);
-
-            var out_key_len: usize = derived_key.len;
-            const result = crypto.EVP_PKEY_derive(ctx, derived_key.ptr, &out_key_len);
-            if (result != 1) {
-                // Failed on our end.
-                return error.Internal;
-            }
-            // Sanity check.
-            lp.assert(derived_key.len == out_key_len, "SubtleCrypto.deriveBitsX25519", .{});
-
-            // Length is in bits, convert to byte length.
-            const length = (length_in_bits / 8) + (7 + (length_in_bits % 8)) / 8;
-            // Truncate the slice to specified length.
-            // Same as `derived_key`.
-            const tailored = blk: {
-                if (length > derived_key.len) {
-                    return error.LengthTooLong;
-                }
-                break :blk derived_key[0..length];
-            };
-
-            // Zero any "unused bits" in the final byte.
-            const remainder_bits: u3 = @intCast(length_in_bits % 8);
-            if (remainder_bits != 0) {
-                tailored[tailored.len - 1] &= ~(@as(u8, 0xFF) >> remainder_bits);
-            }
-
-            return js.ArrayBuffer{ .values = tailored };
-        }
-
-        // Failed on our end.
-        return error.Internal;
-    }
-
-    pub const JsApi = struct {
-        pub const bridge = js.Bridge(CryptoKey);
-
-        pub const Meta = struct {
-            pub const name = "CryptoKey";
-
-            pub var class_id: bridge.ClassId = undefined;
-            pub const prototype_chain = bridge.prototypeChain();
-        };
-    };
-};
 
 pub const JsApi = struct {
     pub const bridge = js.Bridge(SubtleCrypto);

src/browser/webapi/URL.zig

@@ -37,6 +37,14 @@ pub const resolve = @import("../URL.zig").resolve;
 pub const eqlDocument = @import("../URL.zig").eqlDocument;
 
 pub fn init(url: [:0]const u8, base_: ?[:0]const u8, page: *Page) !*URL {
+    const arena = page.arena;
+
+    if (std.mem.eql(u8, url, "about:blank")) {
+        return page._factory.create(URL{
+            ._raw = "about:blank",
+            ._arena = arena,
+        });
+    }
     const url_is_absolute = @import("../URL.zig").isCompleteHTTPUrl(url);
 
     const base = if (base_) |b| blk: {
@@ -53,7 +61,6 @@ pub fn init(url: [:0]const u8, base_: ?[:0]const u8, page: *Page) !*URL {
         return error.TypeError;
     } else page.url;
 
-    const arena = page.arena;
     const raw = try resolve(arena, base, url, .{ .always_dupe = true });
 
     return page._factory.create(URL{

src/browser/webapi/Window.zig

@@ -285,23 +285,23 @@ pub fn queueMicrotask(_: *Window, cb: js.Function, page: *Page) void {
 }
 
 pub fn clearTimeout(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
+    var sc = self._timers.fetchRemove(id) orelse return;
-    sc.removed = true;
+    sc.value.removed = true;
 }
 
 pub fn clearInterval(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
+    var sc = self._timers.fetchRemove(id) orelse return;
-    sc.removed = true;
+    sc.value.removed = true;
 }
 
 pub fn clearImmediate(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
+    var sc = self._timers.fetchRemove(id) orelse return;
-    sc.removed = true;
+    sc.value.removed = true;
 }
 
 pub fn cancelAnimationFrame(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
+    var sc = self._timers.fetchRemove(id) orelse return;
-    sc.removed = true;
+    sc.value.removed = true;
 }
 
 const RequestIdleCallbackOpts = struct {
@@ -319,8 +319,8 @@ pub fn requestIdleCallback(self: *Window, cb: js.Function.Temp, opts_: ?RequestI
 }
 
 pub fn cancelIdleCallback(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
+    var sc = self._timers.fetchRemove(id) orelse return;
-    sc.removed = true;
+    sc.value.removed = true;
 }
 
 pub fn reportError(self: *Window, err: js.Value, page: *Page) !void {
@@ -704,7 +704,6 @@ const ScheduleCallback = struct {
         const window = page.window;
 
         if (self.removed) {
-            _ = window._timers.remove(self.timer_id);
             self.deinit();
             return null;
         }

src/browser/webapi/collections/node_live.zig

@@ -62,7 +62,7 @@ const Filters = union(Mode) {
     selected_options,
     links,
     anchors,
-    form: *Form,
+    form: struct { form: *Form, form_id: ?[]const u8 },
 
     fn TypeOf(comptime mode: Mode) type {
         @setEvalBranchQuota(2000);
@@ -304,9 +304,13 @@ pub fn NodeLive(comptime mode: Mode) type {
                         return false;
                     }
 
-                    if (el.getAttributeSafe(comptime .wrap("form"))) |form_attr| {
+                    if (self._filter.form_id) |form_id| {
-                        const form_id = self._filter.asElement().getAttributeSafe(comptime .wrap("id")) orelse return false;
+                        if (el.getAttributeSafe(comptime .wrap("form"))) |element_form_attr| {
-                        return std.mem.eql(u8, form_attr, form_id);
+                            return std.mem.eql(u8, element_form_attr, form_id);
+                        }
+                    } else if (el.hasAttributeSafe(comptime .wrap("form"))) {
+                        // Form has no id, element explicitly references another form
+                        return false;
                     }
 
                     // No form attribute - match if descendant of our form
@@ -324,7 +328,7 @@ pub fn NodeLive(comptime mode: Mode) type {
                     // This trades one O(form_size) reverse walk for N O(depth) ancestor
                     // checks, where N = number of controls. For forms with many nested
                     // controls, this could be significantly faster.
-                    return self._filter.asNode().contains(node);
+                    return self._filter.form.asNode().contains(node);
                 },
             }
         }