mozilla-release/testing/web-platform/tests/fullscreen/api/element-request-fullscreen-twice-manual.tentative.html

<!DOCTYPE html>
<!--
   Tentative due to:
    https://github.com/whatwg/fullscreen/issues/152

-->
<title>Element#requestFullscreen() twice</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../trusted-click.js"></script>
<div id="log"></div>
<script>
promise_test(async (test) => {
  const div = document.querySelector("div");

  const fullscreenChangePromise = new Promise((resolve, reject) => {
    document.onfullscreenchange = test.step_func(() => {
      assert_equals(document.fullscreenElement, div);
      // Ensure that there's only one fullscreenchange event.
      document.onfullscreenchange = test.unreached_func("second fullscreenchange event");
      resolve();
    });
  });

  const fullscreenErrorPromise = new Promise((resolve, reject) => {
    document.onfullscreenerror = test.step_func(() => {
      resolve();
    });
  });

  trusted_click(test, () => {
    // Request fullscreen twice.
    div.requestFullscreen();
    assert_equals(document.fullscreenElement, null, "fullscreenElement after first requestFullscreen()");
    var p = div.requestFullscreen();
    if (p) {
      p.then(test.unreached_func("promise unexpectedly resolved"), ()=>{});
    }
  }, document.body);

  await Promise.all([
    fullscreenChangePromise,
    fullscreenErrorPromise,
  ]);
});
</script>