Merge pull request #1516 from lightpanda-io/unhandle_rejection_callback

Adds PromiseRejectionCallback

src/browser/js/Context.zig

@@ -105,6 +105,7 @@ global_promise_resolvers: std.ArrayList(v8.Global) = .empty,
 // Temp variants stored in HashMaps for O(1) early cleanup.
 // Key is global.data_ptr.
 global_values_temp: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
+global_promises_temp: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
 global_functions_temp: std.AutoHashMapUnmanaged(usize, v8.Global) = .empty,
 
 // Our module cache: normalized module specifier => module.
@@ -233,6 +234,13 @@ pub fn deinit(self: *Context) void {
         }
     }
 
+    {
+        var it = self.global_promises_temp.valueIterator();
+        while (it.next()) |global| {
+            v8.v8__Global__Reset(global);
+        }
+    }
+
     {
         var it = self.global_functions_temp.valueIterator();
         while (it.next()) |global| {
@@ -309,6 +317,7 @@ pub fn release(self: *Context, item: anytype) void {
 
     var map = switch (@TypeOf(item)) {
         js.Value.Temp => &self.global_values_temp,
+        js.Promise.Temp => &self.global_promises_temp,
         js.Function.Temp => &self.global_functions_temp,
         else => |T| @compileError("Context.release cannot be called with a " ++ @typeName(T)),
     };

src/browser/js/Env.zig

@@ -383,17 +383,13 @@ fn promiseRejectCallback(message_handle: v8.PromiseRejectMessage) callconv(.c) v
         .call_arena = ctx.call_arena,
     };
 
-    const value =
-        if (v8.v8__PromiseRejectMessage__GetValue(&message_handle)) |v8_value|
-            js.Value.toStringSlice(.{ .local = &local, .handle = v8_value }) catch |err| @errorName(err)
-        else
-            "no value";
-
-    log.debug(.js, "unhandled rejection", .{
-        .value = value,
-        .stack = local.stackTrace() catch |err| @errorName(err) orelse "???",
-        .note = "This should be updated to call window.unhandledrejection",
-    });
+    const page = ctx.page;
+    page.window.unhandledPromiseRejection(.{
+        .local = &local,
+        .handle = &message_handle,
+    }, page) catch |err| {
+        log.warn(.browser, "unhandled rejection handler", .{ .err = err });
+    };
 }
 
 fn fatalCallback(c_location: [*c]const u8, c_message: [*c]const u8) callconv(.c) void {

src/browser/js/Local.zig

@@ -323,6 +323,7 @@ pub fn zigValueToJs(self: *const Local, value: anytype, comptime opts: CallOpts)
                 js.Value.Temp,
                 js.Object.Global,
                 js.Promise.Global,
+                js.Promise.Temp,
                 js.PromiseResolver.Global,
                 js.Module.Global => return .{ .local = self, .handle = @ptrCast(value.local(self).handle) },
                 else => {}
@@ -619,15 +620,19 @@ fn jsValueToStruct(self: *const Local, comptime T: type, js_val: js.Value) !?T {
             return try obj.persist();
         },
 
-        js.Promise.Global => {
+        js.Promise.Global, js.Promise.Temp => {
             if (!js_val.isPromise()) {
                 return null;
             }
-            const promise = js.Promise{
-                .ctx = self,
+            const js_promise = js.Promise{
+                .local = self,
                 .handle = @ptrCast(js_val.handle),
             };
-            return try promise.persist();
+            return switch (T) {
+                js.Promise.Temp => try js_promise.temp(),
+                js.Promise.Global => try js_promise.persist(),
+                else => unreachable,
+            };
         },
         string.String => {
             const js_str = js_val.isString() orelse return null;

src/browser/js/Promise.zig

@@ -47,25 +47,49 @@ pub fn thenAndCatch(self: Promise, on_fulfilled: js.Function, on_rejected: js.Fu
     }
     return error.PromiseChainFailed;
 }
+
 pub fn persist(self: Promise) !Global {
+    return self._persist(true);
+}
+
+pub fn temp(self: Promise) !Temp {
+    return self._persist(false);
+}
+
+fn _persist(self: *const Promise, comptime is_global: bool) !(if (is_global) Global else Temp) {
     var ctx = self.local.ctx;
+
     var global: v8.Global = undefined;
     v8.v8__Global__New(ctx.isolate.handle, self.handle, &global);
-    try ctx.global_promises.append(ctx.arena, global);
+    if (comptime is_global) {
+        try ctx.global_promises.append(ctx.arena, global);
+    } else {
+        try ctx.global_promises_temp.put(ctx.arena, global.data_ptr, global);
+    }
     return .{ .handle = global };
 }
 
-pub const Global = struct {
-    handle: v8.Global,
+pub const Temp = G(0);
+pub const Global = G(1);
 
-    pub fn deinit(self: *Global) void {
-        v8.v8__Global__Reset(&self.handle);
-    }
+fn G(comptime discriminator: u8) type {
+    return struct {
+        handle: v8.Global,
 
-    pub fn local(self: *const Global, l: *const js.Local) Promise {
-        return .{
-            .local = l,
-            .handle = @ptrCast(v8.v8__Global__Get(&self.handle, l.isolate.handle)),
-        };
-    }
-};
+        // makes the types different (G(0) != G(1)), without taking up space
+        comptime _: u8 = discriminator,
+
+        const Self = @This();
+
+        pub fn deinit(self: *Self) void {
+            v8.v8__Global__Reset(&self.handle);
+        }
+
+        pub fn local(self: *const Self, l: *const js.Local) Promise {
+            return .{
+                .local = l,
+                .handle = @ptrCast(v8.v8__Global__Get(&self.handle, l.isolate.handle)),
+            };
+        }
+    };
+}

src/browser/js/PromiseRejection.zig

@@ -0,0 +1,41 @@
+// 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 js = @import("js.zig");
+const v8 = js.v8;
+
+const PromiseRejection = @This();
+
+local: *const js.Local,
+handle: *const v8.PromiseRejectMessage,
+
+pub fn promise(self: PromiseRejection) js.Promise {
+    return .{
+        .local = self.local,
+        .handle = v8.v8__PromiseRejectMessage__GetPromise(self.handle).?,
+    };
+}
+
+pub fn reason(self: PromiseRejection) ?js.Value {
+    const value_handle = v8.v8__PromiseRejectMessage__GetValue(self.handle) orelse return null;
+
+    return .{
+        .local = self.local,
+        .handle = value_handle,
+    };
+}

src/browser/js/bridge.zig

@@ -879,6 +879,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/event/MouseEvent.zig"),
     @import("../webapi/event/PointerEvent.zig"),
     @import("../webapi/event/KeyboardEvent.zig"),
+    @import("../webapi/event/PromiseRejectionEvent.zig"),
     @import("../webapi/MessageChannel.zig"),
     @import("../webapi/MessagePort.zig"),
     @import("../webapi/media/MediaError.zig"),

src/browser/js/js.zig

@@ -44,6 +44,7 @@ pub const BigInt = @import("BigInt.zig");
 pub const Number = @import("Number.zig");
 pub const Integer = @import("Integer.zig");
 pub const PromiseResolver = @import("PromiseResolver.zig");
+pub const PromiseRejection = @import("PromiseRejection.zig");
 
 const Allocator = std.mem.Allocator;
 

src/browser/tests/event/promise_rejection.html

@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+
+<script id=project_rejection>
+  {
+    let e1 = new PromiseRejectionEvent("rejectionhandled");
+    testing.expectEqual(true, e1 instanceof PromiseRejectionEvent);
+    testing.expectEqual(true, e1 instanceof Event);
+
+    testing.expectEqual("rejectionhandled", e1.type);
+    testing.expectEqual(null, e1.reason);
+    testing.expectEqual(null, e1.promise);
+
+    let e2 = new PromiseRejectionEvent("rejectionhandled", {reason: ['tea']});
+    testing.expectEqual(true, e2 instanceof PromiseRejectionEvent);
+    testing.expectEqual(true, e2 instanceof Event);
+
+    testing.expectEqual("rejectionhandled", e2.type);
+    testing.expectEqual(['tea'], e2.reason);
+    testing.expectEqual(null, e2.promise);
+  }
+</script>

src/browser/tests/window/window.html

@@ -114,3 +114,30 @@
   testing.expectEqual(24, screen.pixelDepth);
   testing.expectEqual(screen, window.screen);
 </script>
+
+<script id=unhandled_rejection>
+  {
+    let unhandledCalled = 0;
+    window.onunhandledrejection = function(e) {
+      testing.expectEqual(true, e instanceof PromiseRejectionEvent);
+      testing.expectEqual({x: 'Fail'}, e.reason);
+      testing.expectEqual('unhandledrejection', e.type);
+      testing.expectEqual(window, e.target);
+      testing.expectEqual(window, e.srcElement);
+      testing.expectEqual(window, e.currentTarget);
+      unhandledCalled += 1;
+    }
+
+    window.addEventListener('unhandledrejection', function(e) {
+      testing.expectEqual(true, e instanceof PromiseRejectionEvent);
+      testing.expectEqual({x: 'Fail'}, e.reason);
+      testing.expectEqual('unhandledrejection', e.type);
+      testing.expectEqual(window, e.target);
+      testing.expectEqual(window, e.srcElement);
+      testing.expectEqual(window, e.currentTarget);
+      unhandledCalled += 1;
+    });
+    Promise.reject({x: 'Fail'});
+    testing.eventually(() => testing.expectEqual(2, unhandledCalled));
+  }
+</script>

src/browser/webapi/Event.zig

@@ -71,6 +71,7 @@ pub const Type = union(enum) {
     page_transition_event: *@import("event/PageTransitionEvent.zig"),
     pop_state_event: *@import("event/PopStateEvent.zig"),
     ui_event: *@import("event/UIEvent.zig"),
+    promise_rejection_event: *@import("event/PromiseRejectionEvent.zig"),
 };
 
 pub const Options = struct {
@@ -150,6 +151,7 @@ pub fn is(self: *Event, comptime T: type) ?*T {
         .navigation_current_entry_change_event => |e| return if (T == @import("event/NavigationCurrentEntryChangeEvent.zig")) e else null,
         .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,
         .ui_event => |e| {
             if (T == @import("event/UIEvent.zig")) {
                 return e;

src/browser/webapi/MessagePort.zig

@@ -48,7 +48,7 @@ pub fn entangle(port1: *MessagePort, port2: *MessagePort) void {
     port2._entangled_port = port1;
 }
 
-pub fn postMessage(self: *MessagePort, message: js.Value.Global, page: *Page) !void {
+pub fn postMessage(self: *MessagePort, message: js.Value.Temp, page: *Page) !void {
     if (self._closed) {
         return;
     }
@@ -106,7 +106,7 @@ pub fn setOnMessageError(self: *MessagePort, cb: ?js.Function.Global) !void {
 
 const PostMessageCallback = struct {
     port: *MessagePort,
-    message: js.Value.Global,
+    message: js.Value.Temp,
     page: *Page,
 
     fn deinit(self: *PostMessageCallback) void {

src/browser/webapi/Window.zig

@@ -44,6 +44,8 @@ const CSSStyleProperties = @import("css/CSSStyleProperties.zig");
 const CustomElementRegistry = @import("CustomElementRegistry.zig");
 const Selection = @import("Selection.zig");
 
+const IS_DEBUG = builtin.mode == .Debug;
+
 const Allocator = std.mem.Allocator;
 
 const Window = @This();
@@ -278,7 +280,7 @@ pub fn cancelIdleCallback(self: *Window, id: u32) void {
 
 pub fn reportError(self: *Window, err: js.Value, page: *Page) !void {
     const error_event = try ErrorEvent.initTrusted(comptime .wrap("error"), .{
-        .@"error" = try err.persist(),
+        .@"error" = try err.temp(),
         .message = err.toStringSlice() catch "Unknown error",
         .bubbles = false,
         .cancelable = true,
@@ -342,7 +344,7 @@ pub fn getComputedStyle(_: *const Window, element: *Element, pseudo_element: ?[]
     return CSSStyleProperties.init(element, true, page);
 }
 
-pub fn postMessage(self: *Window, message: js.Value.Global, target_origin: ?[]const u8, page: *Page) !void {
+pub fn postMessage(self: *Window, message: js.Value.Temp, target_origin: ?[]const u8, page: *Page) !void {
     // For now, we ignore targetOrigin checking and just dispatch the message
     // In a full implementation, we would validate the origin
     _ = target_origin;
@@ -487,6 +489,28 @@ pub fn scrollTo(self: *Window, opts: ScrollToOpts, y: ?i32, page: *Page) !void {
     );
 }
 
+pub fn unhandledPromiseRejection(self: *Window, rejection: js.PromiseRejection, page: *Page) !void {
+    if (comptime IS_DEBUG) {
+        log.debug(.js, "unhandled rejection", .{
+            .value = rejection.reason(),
+            .stack = rejection.local.stackTrace() catch |err| @errorName(err) orelse "???",
+        });
+    }
+
+    var event = (try @import("event/PromiseRejectionEvent.zig").init("unhandledrejection", .{
+        .reason = if (rejection.reason()) |r| try r.temp() else null,
+        .promise = try rejection.promise().temp(),
+    }, page)).asEvent();
+    defer if (!event._v8_handoff) event.deinit(false);
+
+    try page._event_manager.dispatchWithFunction(
+        self.asEventTarget(),
+        event,
+        rejection.local.toLocal(self._on_unhandled_rejection),
+        .{ .inject_target = true, .context = "window.unhandledrejection" },
+    );
+}
+
 const ScheduleOpts = struct {
     repeat: bool,
     params: []js.Value.Temp,
@@ -626,7 +650,7 @@ const PostMessageCallback = struct {
     page: *Page,
     arena: Allocator,
     origin: []const u8,
-    message: js.Value.Global,
+    message: js.Value.Temp,
 
     fn deinit(self: *PostMessageCallback) void {
         self.page.releaseArena(self.arena);

src/browser/webapi/event/CompositionEvent.zig

@@ -16,7 +16,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 const std = @import("std");
-const String = @import("../../..//string.zig").String;
+const String = @import("../../../string.zig").String;
 
 const js = @import("../../js/js.zig");
 const Page = @import("../../Page.zig");

src/browser/webapi/event/CustomEvent.zig

@@ -17,7 +17,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const String = @import("../../..//string.zig").String;
+const String = @import("../../../string.zig").String;
 
 const js = @import("../../js/js.zig");
 const Page = @import("../../Page.zig");
@@ -27,11 +27,11 @@ const Allocator = std.mem.Allocator;
 const CustomEvent = @This();
 
 _proto: *Event,
-_detail: ?js.Value.Global = null,
+_detail: ?js.Value.Temp = null,
 _arena: Allocator,
 
 const CustomEventOptions = struct {
-    detail: ?js.Value.Global = null,
+    detail: ?js.Value.Temp = null,
 };
 
 const Options = Event.inheritOptions(CustomEvent, CustomEventOptions);
@@ -61,7 +61,7 @@ pub fn initCustomEvent(
     event_string: []const u8,
     bubbles: ?bool,
     cancelable: ?bool,
-    detail_: ?js.Value.Global,
+    detail_: ?js.Value.Temp,
 ) !void {
     // This function can only be called after the constructor has called.
     // So we assume proto is initialized already by constructor.
@@ -73,14 +73,18 @@ pub fn initCustomEvent(
 }
 
 pub fn deinit(self: *CustomEvent, shutdown: bool) void {
-    self._proto.deinit(shutdown);
+    const proto = self._proto;
+    if (self._detail) |d| {
+        proto._page.js.release(d);
+    }
+    proto.deinit(shutdown);
 }
 
 pub fn asEvent(self: *CustomEvent) *Event {
     return self._proto;
 }
 
-pub fn getDetail(self: *const CustomEvent) ?js.Value.Global {
+pub fn getDetail(self: *const CustomEvent) ?js.Value.Temp {
     return self._detail;
 }
 

src/browser/webapi/event/ErrorEvent.zig

@@ -32,7 +32,7 @@ _message: []const u8 = "",
 _filename: []const u8 = "",
 _line_number: u32 = 0,
 _column_number: u32 = 0,
-_error: ?js.Value.Global = null,
+_error: ?js.Value.Temp = null,
 _arena: Allocator,
 
 pub const ErrorEventOptions = struct {
@@ -40,7 +40,7 @@ pub const ErrorEventOptions = struct {
     filename: ?[]const u8 = null,
     lineno: u32 = 0,
     colno: u32 = 0,
-    @"error": ?js.Value.Global = null,
+    @"error": ?js.Value.Temp = null,
 };
 
 const Options = Event.inheritOptions(ErrorEvent, ErrorEventOptions);
@@ -80,7 +80,11 @@ fn initWithTrusted(arena: Allocator, typ: String, opts_: ?Options, trusted: bool
 }
 
 pub fn deinit(self: *ErrorEvent, shutdown: bool) void {
-    self._proto.deinit(shutdown);
+    const proto = self._proto;
+    if (self._error) |e| {
+        proto._page.js.release(e);
+    }
+    proto.deinit(shutdown);
 }
 
 pub fn asEvent(self: *ErrorEvent) *Event {
@@ -103,7 +107,7 @@ pub fn getColumnNumber(self: *const ErrorEvent) u32 {
     return self._column_number;
 }
 
-pub fn getError(self: *const ErrorEvent) ?js.Value.Global {
+pub fn getError(self: *const ErrorEvent) ?js.Value.Temp {
     return self._error;
 }
 

src/browser/webapi/event/MessageEvent.zig

@@ -29,12 +29,12 @@ const Allocator = std.mem.Allocator;
 const MessageEvent = @This();
 
 _proto: *Event,
-_data: ?js.Value.Global = null,
+_data: ?js.Value.Temp = null,
 _origin: []const u8 = "",
 _source: ?*Window = null,
 
 const MessageEventOptions = struct {
-    data: ?js.Value.Global = null,
+    data: ?js.Value.Temp = null,
     origin: ?[]const u8 = null,
     source: ?*Window = null,
 };
@@ -73,14 +73,18 @@ fn initWithTrusted(arena: Allocator, typ: String, opts_: ?Options, trusted: bool
 }
 
 pub fn deinit(self: *MessageEvent, shutdown: bool) void {
-    self._proto.deinit(shutdown);
+    const proto = self._proto;
+    if (self._data) |d| {
+        proto._page.js.release(d);
+    }
+    proto.deinit(shutdown);
 }
 
 pub fn asEvent(self: *MessageEvent) *Event {
     return self._proto;
 }
 
-pub fn getData(self: *const MessageEvent) ?js.Value.Global {
+pub fn getData(self: *const MessageEvent) ?js.Value.Temp {
     return self._data;
 }
 

src/browser/webapi/event/PromiseRejectionEvent.zig

@@ -0,0 +1,102 @@
+// 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 String = @import("../../../string.zig").String;
+
+const js = @import("../../js/js.zig");
+const Page = @import("../../Page.zig");
+const Event = @import("../Event.zig");
+const Allocator = std.mem.Allocator;
+
+const PromiseRejectionEvent = @This();
+
+_proto: *Event,
+_reason: ?js.Value.Temp = null,
+_promise: ?js.Promise.Temp = null,
+
+const PromiseRejectionEventOptions = struct {
+    reason: ?js.Value.Temp = null,
+    promise: ?js.Promise.Temp = null,
+};
+
+const Options = Event.inheritOptions(PromiseRejectionEvent, PromiseRejectionEventOptions);
+
+pub fn init(typ: []const u8, opts_: ?Options, page: *Page) !*PromiseRejectionEvent {
+    const arena = try page.getArena(.{ .debug = "PromiseRejectionEvent" });
+    errdefer page.releaseArena(arena);
+    const type_string = try String.init(arena, typ, .{});
+
+    const opts = opts_ orelse Options{};
+    const event = try page._factory.event(
+        arena,
+        type_string,
+        PromiseRejectionEvent{
+            ._proto = undefined,
+            ._reason = opts.reason,
+            ._promise = opts.promise,
+        },
+    );
+
+    Event.populatePrototypes(event, opts, false);
+    return event;
+}
+
+pub fn deinit(self: *PromiseRejectionEvent, shutdown: bool) void {
+    const proto = self._proto;
+    const js_ctx = proto._page.js;
+    if (self._reason) |r| {
+        js_ctx.release(r);
+    }
+    if (self._promise) |p| {
+        js_ctx.release(p);
+    }
+    proto.deinit(shutdown);
+}
+
+pub fn asEvent(self: *PromiseRejectionEvent) *Event {
+    return self._proto;
+}
+
+pub fn getReason(self: *const PromiseRejectionEvent) ?js.Value.Temp {
+    return self._reason;
+}
+
+pub fn getPromise(self: *const PromiseRejectionEvent) ?js.Promise.Temp {
+    return self._promise;
+}
+
+pub const JsApi = struct {
+    pub const bridge = js.Bridge(PromiseRejectionEvent);
+
+    pub const Meta = struct {
+        pub const name = "PromiseRejectionEvent";
+        pub const prototype_chain = bridge.prototypeChain();
+        pub var class_id: bridge.ClassId = undefined;
+        pub const weak = true;
+        pub const finalizer = bridge.finalizer(PromiseRejectionEvent.deinit);
+    };
+
+    pub const constructor = bridge.constructor(PromiseRejectionEvent.init, .{});
+    pub const reason = bridge.accessor(PromiseRejectionEvent.getReason, null, .{});
+    pub const promise = bridge.accessor(PromiseRejectionEvent.getPromise, null, .{});
+};
+
+const testing = @import("../../../testing.zig");
+test "WebApi: PromiseRejectionEvent" {
+    try testing.htmlRunner("event/promise_rejection.html", .{});
+}

src/browser/webapi/net/XMLHttpRequest.zig

@@ -103,32 +103,33 @@ pub fn deinit(self: *XMLHttpRequest, shutdown: bool) void {
     }
 
     const page = self._page;
+    const js_ctx = page.js;
     if (self._on_ready_state_change) |func| {
-        page.js.release(func);
+        js_ctx.release(func);
     }
 
     {
         const proto = self._proto;
         if (proto._on_abort) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_error) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_load) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_load_end) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_load_start) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_progress) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
         if (proto._on_timeout) |func| {
-            page.js.release(func);
+            js_ctx.release(func);
         }
     }