2 files changed, 33 insertions, 22 deletions
diff --git a/cli/dts/lib.deno.shared_globals.d.ts b/cli/dts/lib.deno.shared_globals.d.ts
index d46a43e67..46154c64e 100644
--- a/cli/dts/lib.deno.shared_globals.d.ts
+++ b/cli/dts/lib.deno.shared_globals.d.ts
@@ -347,24 +347,6 @@ type BufferSource = ArrayBufferView | ArrayBuffer;
 
 declare var console: Console;
 
-interface MessageEventInit<T = any> extends EventInit {
-  data?: T;
-  origin?: string;
-  lastEventId?: string;
-}
-
-declare class MessageEvent<T = any> extends Event {
-  /**
-   * Returns the data of the message.
-   */
-  readonly data: T;
-  /**
-   * Returns the last event ID string, for server-sent events.
-   */
-  readonly lastEventId: string;
-  constructor(type: string, eventInitDict?: MessageEventInit);
-}
-
 interface ErrorEventInit extends EventInit {
   message?: string;
   filename?: string;
@@ -382,10 +364,6 @@ declare class ErrorEvent extends Event {
   constructor(type: string, eventInitDict?: ErrorEventInit);
 }
 
-interface PostMessageOptions {
-  transfer?: any[];
-}
-
 interface AbstractWorkerEventMap {
   "error": ErrorEvent;
 }
diff --git a/cli/tests/unit/message_channel_test.ts b/cli/tests/unit/message_channel_test.ts
new file mode 100644
index 000000000..0cb2671d5
--- /dev/null
+++ b/cli/tests/unit/message_channel_test.ts
@@ -0,0 +1,33 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+// NOTE: these are just sometests to test the TypeScript types. Real coverage is
+// provided by WPT.
+import {
+  assert,
+  assertEquals,
+} from "../../../test_util/std/testing/asserts.ts";
+import { deferred } from "../../../test_util/std/async/deferred.ts";
+
+Deno.test("messagechannel", async () => {
+  const mc = new MessageChannel();
+  const mc2 = new MessageChannel();
+  assert(mc.port1);
+  assert(mc.port2);
+
+  const promise = deferred();
+
+  mc.port2.onmessage = (e) => {
+    assertEquals(e.data, "hello");
+    assertEquals(e.ports.length, 1);
+    assert(e.ports[0] instanceof MessagePort);
+    e.ports[0].close();
+    promise.resolve();
+  };
+
+  mc.port1.postMessage("hello", [mc2.port1]);
+  mc.port1.close();
+
+  await promise;
+
+  mc.port2.close();
+  mc2.port2.close();
+});