media-control-seek-to-action-reaches-client.html

<!DOCTYPE html>
<title>MediaSession Mojo Test</title>
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>
<script type="module">
import {MediaSessionServiceMock} from './resources/mediasessionservice-mock.js';
import {MediaSessionAction} from '/gen/services/media_session/public/mojom/media_session.mojom.m.js';

async_test((t) => {
  const mediaSessionServiceMock = new MediaSessionServiceMock();
  mediaSessionServiceMock.setClientCallback(t.step_func(() => {
    mediaSessionServiceMock.getClient().didReceiveAction(
        MediaSessionAction.kSeekTo,
        {seekTo: {seekTime: {microseconds: 10000000}, fastSeek: true}});
  }));

  window.navigator.mediaSession.setActionHandler("seekto", t.step_func_done((e) => {
    assert_equals(e.action, "seekto");
    assert_equals(e.seekTime, 10);
    assert_true(e.fastSeek);
  }));
}, "test that the seek to action reaches client");
</script>

chromium/third_party/blink/web_tests/http/tests/mediasession/media-control-seek-to-action-reaches-client.html