1test(t => {
2  const input = document.body.appendChild(document.createElement('input'));
3  input.type = "radio";
4  t.add_cleanup(() => input.remove());
5  const clickEvent = new MouseEvent('click', { button: 0, which: 1 });
6  input.addEventListener('change', t.step_func(() => {
7    assert_equals(clickEvent.eventPhase, Event.NONE);
8  }));
9  input.dispatchEvent(clickEvent);
10}, "Use NONE phase during legacy-pre-activation behavior");
11