chromium/third_party/blink/web_tests/external/wpt/service-workers/service-worker/worker-client-id.https.html

<!DOCTYPE html>
<title>Service Worker: Workers should have their own unique client Id</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/test-helpers.sub.js"></script>
<body>
<script>

// Get the iframe client ID by calling postMessage() on its controlling
// worker.  This will cause the service worker to post back the
// MessageEvent.source.id value.
function getFrameClientId(frame) {
  return new Promise(resolve => {
    let mc = new MessageChannel();
    frame.contentWindow.navigator.serviceWorker.controller.postMessage(
      'echo-client-id', [mc.port2]);
    mc.port1.onmessage = evt => {
      resolve(evt.data);
    };
  });
}

// Get the worker client ID by creating a worker that performs an intercepted
// fetch().  The synthetic fetch() response will contain the FetchEvent.clientId
// value.  This is then posted back to here.
function getWorkerClientId(frame) {
  return new Promise(resolve => {
    let w = new frame.contentWindow.Worker('worker-echo-client-id.js');
    w.onmessage = evt => {
      resolve(evt.data);
    };
  });
}

promise_test(async function(t) {
  const script = './resources/worker-client-id-worker.js';
  const scope = './resources/worker-client-id';
  const frame = scope + '/frame.html';

  let reg = await navigator.serviceWorker.register(script, { scope });
  t.add_cleanup(async _ => await reg.unregister());
  await wait_for_state(t, reg.installing, 'activated');

  let f = await with_iframe(frame);
  t.add_cleanup(_ => f.remove());

  let frameClientId = await getFrameClientId(f);
  assert_not_equals(frameClientId, null, 'frame client id should exist');

  let workerClientId = await getWorkerClientId(f);
  assert_not_equals(workerClientId, null, 'worker client id should exist');

  assert_not_equals(frameClientId, workerClientId,
                    'frame and worker client ids should be different');
}, 'Verify workers have a unique client id separate from their owning documents window');

</script>
</body>