animation-worklet/worklet-animation-cancel.https.html

<html class="reftest-wait">
<title>Canceling a playing WorkletAnimation should remove the effect</title>
<link rel="help" href="https://drafts.css-houdini.org/css-animationworklet/">
<meta name="assert" content="Canceling a playing animation should remove the effect">
<link rel="match" href="references/not-translated-box-ref.html">

<script src="/web-animations/testcommon.js"></script>
<script src="/common/reftest-wait.js"></script>
<script src="common.js"></script>

<style>
  #box {
    width: 100px;
    height: 100px;
    background-color: green;
  }
</style>

<div id="box"></div>

<script>
  registerConstantLocalTimeAnimator(500).then(_ => {
    const box = document.getElementById('box');
    const effect = new KeyframeEffect(box,
      [
        {transform: 'translateY(0)'},
        {transform: 'translateY(200px)'}
      ], {
        duration: 1000,
        iterations: Infinity
      }
    );

    const animation = new WorkletAnimation('constant_time', effect);
    animation.play();

    waitForAsyncAnimationFrames(1).then(_ => {
      // Canceling a playing animation should remove the effect.
      animation.cancel();
      waitForAsyncAnimationFrames(1).then(_ => {
        takeScreenshot();
      });
    });
  });
</script>