event-before-promise.html | Explore in Territory

<!DOCTYPE html>
<meta charset="utf-8" />
<meta viewport="width=device-width, initial-scale=1" />
<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 type="module">
  import {
    getOppositeOrientation,
    makeCleanup,
  } from "./resources/orientation-utils.js";

  promise_test(async (t) => {
    t.add_cleanup(makeCleanup());
    await test_driver.bless("request full screen");
    await document.documentElement.requestFullscreen();
    const result = await Promise.race([
      new Promise((resolve) => {
        screen.orientation.addEventListener("change", resolve);
      }),
      screen.orientation.lock(getOppositeOrientation())
    ]);
    assert_true(result instanceof Event, "Expected an instance of Event");
  }, "The 'change' event must fire before the [[orientationPendingPromise]] is resolved.");
</script>

chromium/third_party/blink/web_tests/external/wpt/screen-orientation/event-before-promise.html