event-timing/disconnect-target.html

<!DOCTYPE html>
<html>
<meta charset=utf-8 />
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=/resources/testdriver.js></script>
<script src=/resources/testdriver-vendor.js></script>

<script src=resources/event-timing-test-utils.js></script>

<button id='the_button'>ClickMe</button>

<script>
async_test(function(t) {
  assert_implements(window.PerformanceEventTiming, 'Event Timing is not supported.');
  const observer = new PerformanceObserver(t.step_func_done((entryList) => {
    const entries = entryList.getEntries().filter(e => e.name === 'pointerdown');
    if (entries.length === 0)
      return;
    // There must only be one click entry.
    assert_equals(entries.length, 1);
    const entry = entries[0];
    // This checks that entry.target returns the correct button Node.
    verifyClickEvent(entry, 'the_button', true);
    const button = document.getElementById('the_button');
    button.parentNode.removeChild(button);
    // After removing the button, entry.target should now return null.
    assert_equals(entry.target, null);
  }));
  observer.observe({entryTypes: ['event']});
  clickAndBlockMain('the_button');
}, "Event Timing: when target is disconnected, entry.target returns null.");
</script>
</html>