scroll-event-handler-reused-window.html

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<body>
<script>
let finishTestPromiseResolver = null;
const finishTestPromise = new Promise(resolve => finishTestPromiseResolver = resolve);

function concludeTest() {
  finishTestPromiseResolver();
}

promise_test(async () => {
  if (window.testRunner) {
    testRunner.setPopupBlockingEnabled(false);
    testRunner.waitUntilDone();
  }

  // |window.open| returns a DOMWindow synchronously without waiting for the
  // network load to finish. Once the load completes, we transition the existing
  // window object to the document instead of creating a new one like we normally
  // would. The purpose of this test is to ensure event handlers added on the
  // window are still present after the window is reused with the new document.
  // See DocumentLoader.cpp for details.
  const newWindow = window.open('resources/conclude-test-in-parent.html');
  newWindow.onscroll = function() {};

  await finishTestPromise;
  assert_equals(internals.scrollEventHandlerCount(newWindow.document), 1);
}, 'Test tracking event handlers with a reused DOMWindow.');
</script>
chromium/third_party/blink/web_tests/fast/events/scroll-event-handler-reused-window.html
