animation-worklet/animator-with-options.https.html

<!DOCTYPE html>
<title>Worklet Animation with options</title>
<link rel="help" href="https://drafts.css-houdini.org/css-animationworklet/">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/web-animations/testcommon.js"></script>
<script src="common.js"></script>

<div id="target"></div>

<script id="animate_with_options" type="text/worklet">
  registerAnimator("test_animator", class {
    constructor(options) {
      this.time_ = options.time;
    }
    animate(currentTime, effect) {
      effect.localTime = this.time_;
    }
  });
</script>

<script>
  promise_test(async t => {
    await runInAnimationWorklet(document.getElementById('animate_with_options').textContent);
    const target = document.getElementById('target');
    const effect = new KeyframeEffect(target, [{ opacity: 0 }], { duration: 1000 });
    const options = {'time': 500};
    const animation = new WorkletAnimation('test_animator', effect, document.timeline, options);
    animation.play();

    // wait until local times are synced back to the main thread.
    await waitForAnimationFrameWithCondition(_ => {
      return getComputedStyle(target).opacity != '1';
    });
    assert_equals(getComputedStyle(target).opacity, "0.5");
  }, "Animator should be able to use options to update the animation");
</script>