broadcast-channel.html | Explore in Territory

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="utils.js"></script>
<script src="deferred-promise-utils.js"></script>
<script>

const params = new URLSearchParams(location.search);

// The main test page (restriction-broadcast-channel.html) loads the initiator
// page, then the initiator page will prerender itself with the `prerendering`
// parameter.
const isPrerendering = params.has('prerendering');

if (!isPrerendering) {
  loadInitiatorPage();
} else {
  const prerenderEventCollector = new PrerenderEventCollector();

  // Create separate channels as a sender channel cannot receive a message sent
  // by itself.
  const sender = new BroadcastChannel('test');
  const receiver = new BroadcastChannel('test');

  const promise = new Promise(resolve => {
    receiver.onmessage = e => {
      prerenderEventCollector.addEvent(`received message: ${e.data}`);
      resolve();
    };
  });
  sender.postMessage('hello');

  prerenderEventCollector.start(promise, 'BroadcastChannel');
}
</script>

chromium/third_party/blink/web_tests/external/wpt/speculation-rules/prerender/resources/broadcast-channel.html