broadcastchannel-incumbent.sub.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>The incumbent page being cross-origin must not prevent the BroadcastChannel message from being seen</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<!-- This is the entry global -->

<iframe src="http://{{hosts[][www]}}:{{ports[http][0]}}/webmessaging/multi-globals/support/incumbent-document-domain.sub.html" id="incumbent"></iframe>
<iframe src="support/current-document-domain.sub.html" id="current"></iframe>

<script>
"use strict";
document.domain = "{{hosts[][]}}";

setup({ explicit_done: true });

const incumbentIframe = document.querySelector("#incumbent");
const currentIframe = document.querySelector("#current");

window.onload = () => {
  async_test(t => {
    const createdThroughCrossOrigin = frames[0].createBroadcastChannel("incumbent");
    const createdSameOrigin = new BroadcastChannel("incumbent");

    createdSameOrigin.onmessage = () => t.done();
    createdSameOrigin.onmessageerror = t.unreached_func("messageerror event fired");

    createdThroughCrossOrigin.postMessage("the message");
  });

  done();
};
</script>

chromium/third_party/blink/web_tests/external/wpt/webmessaging/multi-globals/broadcastchannel-incumbent.sub.html