setting-the-playback-rate-of-an-animation.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /web-animations/timing-model/animations/setting-the-playback-rate-of-an-animation.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset=utf-8>

<title>Setting the playback rate of an animation</title>

<link rel="help" href="https://drafts.csswg.org/web-animations/#setting-the-playback-rate-of-an-animation">

<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(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.playbackRate = 2;

  await animation.ready;

  const previousAnimationCurrentTime = animation.currentTime;

  const previousTimelineCurrentTime = animation.timeline.currentTime;

  await waitForAnimationFrames(1);

  const animationCurrentTimeDifference =

    animation.currentTime - previousAnimationCurrentTime;

  const timelineCurrentTimeDifference =

    animation.timeline.currentTime - previousTimelineCurrentTime;

  assert_times_equal(

    animationCurrentTimeDifference,

    timelineCurrentTimeDifference * animation.playbackRate,

    'The current time should increase two times faster than timeline'

);

}, 'The playback rate affects the rate of progress of the current time');

test(t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 50 * MS_PER_SEC;

  animation.playbackRate = 2;

  assert_time_equals_literal(animation.currentTime, 50 * MS_PER_SEC);

}, 'Setting the playback rate while play-pending preserves the current time');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 50 * MS_PER_SEC;

  await animation.ready;

  animation.playbackRate = 2;

  assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC);

  assert_less_than(animation.currentTime, 100 * MS_PER_SEC);

}, 'Setting the playback rate while playing preserves the current time');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 50 * MS_PER_SEC;

  animation.updatePlaybackRate(2);

  animation.playbackRate = 1;

  await animation.ready;

  assert_equals(animation.playbackRate, 1);

}, 'Setting the playback rate should clear any pending playback rate');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 50 * MS_PER_SEC;

  animation.pause();

  await animation.ready;

  animation.playbackRate = 2;

  // Ensure that the animation remains paused and current time is preserved.

  assert_equals(animation.playState, 'paused');

  assert_time_equals_literal(animation.currentTime, 50 * MS_PER_SEC);

}, 'Setting the playback rate while paused preserves the current time and '

    + 'state');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 150 * MS_PER_SEC;

  await animation.ready;

  animation.playbackRate = 2;

  // Ensure that current time is preserved and does not snap to the effect end

  // time.

  assert_equals(animation.playState, 'finished');

  assert_time_equals_literal(animation.currentTime, 150 * MS_PER_SEC);

}, 'Setting the playback rate while finished preserves the current time');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  animation.currentTime = 150 * MS_PER_SEC;

  await animation.ready;

  assert_equals(animation.playState, 'finished');

  animation.playbackRate = -1;

  // Ensure that current time does not snap to the effect end time and that the

  // animation resumes playing.

  assert_equals(animation.playState, 'running');

  assert_time_equals_literal(animation.currentTime, 150 * MS_PER_SEC);

  await waitForAnimationFrames(2);

  assert_less_than(animation.currentTime, 150 * MS_PER_SEC);

}, 'Reversing the playback rate while finished restarts the animation');

promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  await animation.ready;

  animation.currentTime = 50 * MS_PER_SEC;

  animation.playbackRate = 0;

  // Ensure that current time does not drift.

  assert_equals(animation.playState, 'running');

  await waitForAnimationFrames(2);

  assert_time_equals_literal(animation.currentTime, 50 * MS_PER_SEC);

}, 'Setting a zero playback rate while running preserves the current time');

</script>

</body>