web-animations/timing-model/animations/pausing-an-animation.html

<!DOCTYPE html>
<meta charset=utf-8>
<title>Pausing an animation</title>
<link rel="help"
  href="https://w3c.github.io/web-animations/#pausing-an-animation-section">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../../testcommon.js"></script>
<body>
<div id="log"></div>
<script>
'use strict';

promise_test(t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  const promise = animation.ready;
  animation.pause();
  return promise.then(p => {
    assert_equals(p, animation);
    assert_equals(animation.ready, promise);
    assert_equals(animation.playState, 'paused');
  });
}, 'A pending ready promise should be resolved and not replaced when the'
   + ' animation is paused');

</script>
</body>