animation-worklet/cancel-non-accelerated-property.https.html

<!DOCTYPE html>
<title>Cancel non accelerated property using worklet animation</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>

<style>
#target {
  background-color: red;
}
</style>

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

<script>
  promise_test(async t => {
    await registerConstantLocalTimeAnimator(1000);
    const target = document.getElementById('target');
    const effect = new KeyframeEffect(
        target,
        [
          { background: 'green' },
          { background: 'blue' },
        ],
        {
          duration: 2000,
          iteration: Infinity
        }
    );
    const animation = new WorkletAnimation('constant_time', effect);
    animation.play();

    await waitForAsyncAnimationFrames(1);
    // establish that the animation started
    assert_equals(getComputedStyle(target).backgroundColor, "rgb(0, 64, 128)");
    animation.cancel();

    await waitForAsyncAnimationFrames(1);
    // confirm the animation is cancelled
    assert_equals(getComputedStyle(target).backgroundColor, "rgb(255, 0, 0)");
  }, "Animation should update the outputs after starting and then return to pre-animated values after being cancelled");
</script>