<!DOCTYPE html>
<title>Move the fullscreen element to another document</title>
<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="../trusted-click.js"></script>
<div></div>
<iframe></iframe>
<script>
  promise_test(async (t) => {
    t.add_cleanup(() => {
      if (document.fullscreenElement) {
        return document.exitFullscreen();
      }
    });
    const div = document.querySelector("div");
    const iframe = document.querySelector("iframe");
    const [, event] = await Promise.all([
      trusted_request(div),
      fullScreenChange(),
    ]);

    assert_equals(document.fullscreenElement, div);
    assert_equals(event.target, div);

    assert_equals(div.ownerDocument, document);
    iframe.contentDocument.body.appendChild(div);
    assert_not_equals(div.ownerDocument, document);
    // Moving /div/ removes it from the top layer and thus the fullscreen
    // element synchronously becomes null.
    assert_equals(document.fullscreenElement, null);

    div.onfullscreenchange = t.unreached_func(
      "fullscreenchange fired on element"
    );
    iframe.contentDocument.onfullscreenchange = t.unreached_func(
      "fullscreenchange fired on other document"
    );
    const secondEvent = await fullScreenChange();
    assert_equals(document.fullscreenElement, null);
    assert_equals(secondEvent.target, document);
  });
</script>
