device-posture-event-listener.https.html

<!DOCTYPE html>
<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>
'use strict';

promise_test(async (t) => {
  t.add_cleanup(async () => {
    await test_driver.clear_device_posture();
  });
  assert_equals(navigator.devicePosture.type, 'continuous');

  const promise = new Promise(resolve => {
    navigator.devicePosture.addEventListener(
      'change',
      () => { resolve(navigator.devicePosture.type); },
      { once: true }
    );
  });
  await test_driver.set_device_posture('folded');
  assert_equals(await promise, 'folded');
}, 'Tests the Device Posture API addEventListener change event handler.');
</script>

chromium/third_party/blink/web_tests/external/wpt/device-posture/device-posture-event-listener.https.html