<!DOCTYPE html>
<link rel=author href="mailto:jarhar@chromium.org">
<link rel=help href="https://drafts.csswg.org/css-display-4/#display-animation">
<link rel=help href="https://github.com/w3c/csswg-drafts/issues/6429">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/css-animations/support/testcommon.js"></script>

<div id=target1>hello</div>
<style>
@keyframes display1 {
  0% { display: none; }
  100% { display: inline; }
}
.animate1 {
  animation: display1 1s infinite;
}
</style>
<script>
promise_test(async () => {
  let numAnimationstartFired = 0;
  target1.addEventListener('animationstart', () => numAnimationstartFired++);

  await waitForAnimationFrames(1);
  target1.classList.add('animate1');
  await waitForAnimationFrames(2);

  assert_equals(getComputedStyle(target1).display, 'inline',
    'The display should be inline during the animation.');
  assert_equals(numAnimationstartFired, 1,
    'Only one animation should start.');
}, 'display:none animating to display:inline should be inline for the whole animation.');
</script>

<div id=target2>hello</div>
<style>
@keyframes display2 {
  0% { display: var(--none-value); }
  100% { display: inline; }
}
.animate2 {
  animation: display2 1s infinite;
}
#target2 {
  --none-value: none;
}
</style>
<script>
promise_test(async () => {
  let numAnimationstartFired = 0;
  target2.addEventListener('animationstart', () => numAnimationstartFired++);

  await waitForAnimationFrames(1);
  target2.classList.add('animate2');
  await waitForAnimationFrames(2);

  assert_equals(getComputedStyle(target2).display, 'inline',
    'The display should be inline during the animation.');
  assert_equals(numAnimationstartFired, 1,
    'Only one animation should start.');
}, 'A CSS variable of display:none animating to display:inline should be inline for the whole animation.');
</script>

<div id=target3>hello</div>
<style>
@keyframes display3 {
  0% { display: none; }
  100% { display: none; }
}
.animate3 {
  animation: display3 1s infinite;
}
</style>
<script>
promise_test(async () => {
  let numAnimationstartFired = 0;
  target3.addEventListener('animationstart', () => numAnimationstartFired++);

  await waitForAnimationFrames(1);
  target3.classList.add('animate3');
  await waitForAnimationFrames(2);

  assert_equals(getComputedStyle(target3).display, 'none',
    'The display should be none and the animation should keep running.');
  assert_equals(numAnimationstartFired, 1,
    'Only one animation should start.');
}, 'Animating from display:none to display:none should not cancel the animation.');
</script>

<div id=target4>hello</div>
<style>
@keyframes display4 {
  0% { display: var(--none-value); }
  100% { display: var(--none-value); }
}
.animate4 {
  animation: display4 1s infinite;
}
#target4 {
  --none-value: none;
}
</style>
<script>
promise_test(async () => {
  let numAnimationstartFired = 0;
  target4.addEventListener('animationstart', () => numAnimationstartFired++);

  await waitForAnimationFrames(1);
  target4.classList.add('animate4');
  await waitForAnimationFrames(2);

  assert_equals(getComputedStyle(target4).display, 'none',
    'The display should be none and the animation should keep running.');
  assert_equals(numAnimationstartFired, 1,
    'Only one animation should start.');
}, 'Animating from display:none to display:none with an intermediate variable should not cancel the animation.');
</script>

<div id=target5>hello</div>
<style>
@keyframes display5 {
  0% { --display: none; }
  100% { --display: none; }
}
.animate5 {
  animation: display5 1s infinite;
}
#target5 {
  display: var(--display, block);
}
</style>
<script>
promise_test(async () => {
  let numAnimationstartFired = 0;
  target5.addEventListener('animationstart', () => numAnimationstartFired++);

  await waitForAnimationFrames(1);
  target5.classList.add('animate5');
  await waitForAnimationFrames(2);

  assert_equals(getComputedStyle(target5).display, 'none',
    'The display should be none and the animation should keep running.');
  assert_equals(numAnimationstartFired, 1,
    'Only one animation should start.');
}, 'Animating a variable of "none" which gets set to display elsewhere should not cancel the animation.');
</script>
