mozilla-release/testing/web-platform/tests/cookie-store/serviceworker_cookieStore_subscriptions.tentative.https.html

<!doctype html>
<meta charset="utf-8">
<title>Async Cookies: cookie change events in ServiceWorker</title>
<link rel="help" href="https://github.com/WICG/cookie-store">
<link rel="author" href="pwnall@chromium.org" title="Victor Costan">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
'use strict';

(async () => {
  // Not using an explicit scope here in order for script URL to be in scope,
  // to cover implicit subscription URL construction.

  const registration = await navigator.serviceWorker.register(
      'serviceworker_cookieStore_subscriptions.js');
  add_completion_callback(() => {
    registration.unregister();
  });

  fetch_tests_from_worker(registration.installing);
})();
</script>