worker-postmessage-on-detached-iframe.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Worker: Worker.postMessage() on a detached iframe</title>
<body>
</body>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<script>

function with_iframe(url) {
  return new Promise(resolve => {
      let frame = document.createElement('iframe');
      frame.src = url;
      frame.onload = () => { resolve(frame); };
      document.body.appendChild(frame);
      add_result_callback(() => frame.remove());
    });
}

// This test should not be upstreamed to WPT because the spec does not define
// behavior in the case where Worker.postMessage() is called from a detached
// frame.
promise_test(async t => {
  const frame = await with_iframe('resources/blank.html');
  const worker = new frame.contentWindow.Worker('resources/empty.js');
  frame.remove();
  try {
    worker.postMessage('hello');
  } catch (e) {
    assert_unreached();
  }
}, 'Worker.postMessage() on a detached iframe should not throw an exception ' +
   'nor crash.');

</script>

chromium/third_party/blink/web_tests/http/tests/workers/worker-postmessage-on-detached-iframe.html