LibWeb: Stub BroadcastChannel interface

This is enough to get the 1Password login page to load :^)

Meta/gn/secondary/Userland/Libraries/LibWeb/HTML/BUILD.gn

@@ -15,6 +15,7 @@ source_set("HTML") {
     "AttributeNames.cpp",
     "AudioTrack.cpp",
     "AudioTrackList.cpp",
+    "BroadcastChannel.cpp",
     "BrowsingContext.cpp",
     "BrowsingContextGroup.cpp",
     "CORSSettingAttribute.cpp",

Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni

@@ -110,6 +110,7 @@ standard_idl_files = [
   "//Userland/Libraries/LibWeb/HighResolutionTime/Performance.idl",
   "//Userland/Libraries/LibWeb/HTML/AudioTrack.idl",
   "//Userland/Libraries/LibWeb/HTML/AudioTrackList.idl",
+  "//Userland/Libraries/LibWeb/HTML/BroadcastChannel.idl",
   "//Userland/Libraries/LibWeb/HTML/CanvasGradient.idl",
   "//Userland/Libraries/LibWeb/HTML/CanvasPattern.idl",
   "//Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl",

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -24,6 +24,7 @@ BigInt64Array
 BigUint64Array
 Blob
 Boolean
+BroadcastChannel
 ByteLengthQueuingStrategy
 CDATASection
 CSSAnimation

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -249,6 +249,7 @@ set(SOURCES
     HTML/AttributeNames.cpp
     HTML/AudioTrack.cpp
     HTML/AudioTrackList.cpp
+    HTML/BroadcastChannel.cpp
     HTML/BrowsingContext.cpp
     HTML/BrowsingContextGroup.cpp
     HTML/Canvas/CanvasDrawImage.cpp

Userland/Libraries/LibWeb/Forward.h

@@ -342,6 +342,7 @@ class DOMRectReadOnly;
 namespace Web::HTML {
 class AudioTrack;
 class AudioTrackList;
+class BroadcastChannel;
 class BrowsingContext;
 class BrowsingContextGroup;
 class CanvasRenderingContext2D;

Userland/Libraries/LibWeb/HTML/BroadcastChannel.cpp

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Realm.h>
+#include <LibWeb/Bindings/BroadcastChannelPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/HTML/BroadcastChannel.h>
+#include <LibWeb/HTML/EventNames.h>
+
+namespace Web::HTML {
+
+JS_DEFINE_ALLOCATOR(BroadcastChannel);
+
+JS::NonnullGCPtr<BroadcastChannel> BroadcastChannel::construct_impl(JS::Realm& realm, FlyString const& name)
+{
+    return realm.heap().allocate<BroadcastChannel>(realm, realm, name);
+}
+
+BroadcastChannel::BroadcastChannel(JS::Realm& realm, FlyString const& name)
+    : DOM::EventTarget(realm)
+    , m_channel_name(name)
+{
+}
+
+void BroadcastChannel::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(BroadcastChannel);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-broadcastchannel-name
+FlyString BroadcastChannel::name()
+{
+    // The name getter steps are to return this's channel name.
+    return m_channel_name;
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-broadcastchannel-close
+void BroadcastChannel::close()
+{
+    // The close() method steps are to set this's closed flag to true.
+    m_closed_flag = true;
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#handler-broadcastchannel-onmessage
+void BroadcastChannel::set_onmessage(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::message, event_handler);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#handler-broadcastchannel-onmessage
+WebIDL::CallbackType* BroadcastChannel::onmessage()
+{
+    return event_handler_attribute(HTML::EventNames::message);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#handler-broadcastchannel-onmessageerror
+void BroadcastChannel::set_onmessageerror(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::messageerror, event_handler);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#handler-broadcastchannel-onmessageerror
+WebIDL::CallbackType* BroadcastChannel::onmessageerror()
+{
+    return event_handler_attribute(HTML::EventNames::messageerror);
+}
+
+}

Userland/Libraries/LibWeb/HTML/BroadcastChannel.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/EventTarget.h>
+
+namespace Web::HTML {
+
+class BroadcastChannel final : public DOM::EventTarget {
+    WEB_PLATFORM_OBJECT(BroadcastChannel, DOM::EventTarget);
+    JS_DECLARE_ALLOCATOR(BroadcastChannel);
+
+public:
+    [[nodiscard]] static JS::NonnullGCPtr<BroadcastChannel> construct_impl(JS::Realm&, FlyString const& name);
+
+    FlyString name();
+
+    void close();
+
+    void set_onmessage(WebIDL::CallbackType*);
+    WebIDL::CallbackType* onmessage();
+    void set_onmessageerror(WebIDL::CallbackType*);
+    WebIDL::CallbackType* onmessageerror();
+
+private:
+    BroadcastChannel(JS::Realm&, FlyString const& name);
+
+    virtual void initialize(JS::Realm&) override;
+
+    FlyString m_channel_name;
+    bool m_closed_flag { false };
+};
+
+}

Userland/Libraries/LibWeb/HTML/BroadcastChannel.idl

@@ -0,0 +1,14 @@
+#import <DOM/EventHandler.idl>
+#import <DOM/EventTarget.idl>
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#broadcastchannel
+[Exposed=(Window,Worker)]
+interface BroadcastChannel : EventTarget {
+    constructor(DOMString name);
+
+    readonly attribute DOMString name;
+    [FIXME] undefined postMessage(any message);
+    undefined close();
+    attribute EventHandler onmessage;
+    attribute EventHandler onmessageerror;
+};

Userland/Libraries/LibWeb/idl_files.cmake

@@ -94,6 +94,7 @@ libweb_js_bindings(Geometry/DOMRectList)
 libweb_js_bindings(Geometry/DOMRectReadOnly)
 libweb_js_bindings(HTML/AudioTrack)
 libweb_js_bindings(HTML/AudioTrackList)
+libweb_js_bindings(HTML/BroadcastChannel)
 libweb_js_bindings(HTML/CanvasGradient)
 libweb_js_bindings(HTML/CanvasPattern)
 libweb_js_bindings(HTML/CanvasRenderingContext2D)