<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
  // Waits for 2 messages from portal, one before activation and one after.
  function waitForMessages() {
    return new Promise((resolve, reject) => {
      var results = [];
      var bc = new BroadcastChannel("portals-host-hidden-after-activation");
      bc.onmessage = e => {
        results.push(e.data.hasHost);
        if (results.length == 2) {
          bc.close();
          resolve(results);
        }
      };
    });
  }

  promise_test(async () => {
    assert_implements("HTMLPortalElement" in self);
    const portalUrl = encodeURIComponent("portal-host-hidden-after-activation-portal.html");
    window.open(`resources/portal-embed-and-activate.html?url=${portalUrl}`);
    var results = await waitForMessages();
    assert_true(results[0], "portalHost exposed before calling activate()");
    assert_false(results[1], "portalHost hidden after receiving portalactivate event");
  }, "window.portalHost should be null after portal is activated");
</script>
</body>
