feat(extensions): add BroadcastChannel

Co-Authored-By: Ben Noordhuis <info@bnoordhuis.nl>
Fixes: #10354

1 files changed, 55 insertions, 0 deletions

diff --git a/extensions/broadcast_channel/lib.deno_broadcast_channel.d.ts b/extensions/broadcast_channel/lib.deno_broadcast_channel.d.ts
new file mode 100644
index 000000000..c8efef778
--- /dev/null
+++ b/extensions/broadcast_channel/lib.deno_broadcast_channel.d.ts
@@ -0,0 +1,55 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+// deno-lint-ignore-file no-explicit-any
+
+/// <reference no-default-lib="true" />
+/// <reference lib="esnext" />
+
+interface BroadcastChannelEventMap {
+  "message": MessageEvent;
+  "messageerror": MessageEvent;
+}
+
+interface BroadcastChannel extends EventTarget {
+  /**
+   * Returns the channel name (as passed to the constructor).
+   */
+  readonly name: string;
+  onmessage: ((this: BroadcastChannel, ev: MessageEvent) => any) | null;
+  onmessageerror: ((this: BroadcastChannel, ev: MessageEvent) => any) | null;
+  /**
+   * Closes the BroadcastChannel object, opening it up to garbage collection.
+   */
+  close(): void;
+  /**
+   * Sends the given message to other BroadcastChannel objects set up for
+   * this channel. Messages can be structured objects, e.g. nested objects
+   * and arrays.
+   */
+  postMessage(message: any): void;
+  addEventListener<K extends keyof BroadcastChannelEventMap>(
+    type: K,
+    listener: (this: BroadcastChannel, ev: BroadcastChannelEventMap[K]) => any,
+    options?: boolean | AddEventListenerOptions,
+  ): void;
+  addEventListener(
+    type: string,
+    listener: EventListenerOrEventListenerObject,
+    options?: boolean | AddEventListenerOptions,
+  ): void;
+  removeEventListener<K extends keyof BroadcastChannelEventMap>(
+    type: K,
+    listener: (this: BroadcastChannel, ev: BroadcastChannelEventMap[K]) => any,
+    options?: boolean | EventListenerOptions,
+  ): void;
+  removeEventListener(
+    type: string,
+    listener: EventListenerOrEventListenerObject,
+    options?: boolean | EventListenerOptions,
+  ): void;
+}
+
+declare var BroadcastChannel: {
+  prototype: BroadcastChannel;
+  new (name: string): BroadcastChannel;
+};