<!DOCTYPE html>
<meta charset=utf-8>
<title>The effect value of a keyframe effect: Property values that depend on
  their context (target element)</title>
<link rel="help" href="https://drafts.csswg.org/web-animations/#calculating-computed-keyframes">
<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';

test(t => {
  const div = createDiv(t);
  div.style.fontSize = '10px';
  const animation = div.animate([ { marginLeft: '10em' },
                                  { marginLeft: '20em' } ], 1000);
  animation.currentTime = 500;
  assert_equals(getComputedStyle(div).marginLeft, '150px',
                'Effect value before updating font-size');
  div.style.fontSize = '20px';
  assert_equals(getComputedStyle(div).marginLeft, '300px',
                'Effect value after updating font-size');
}, 'Effect values reflect changes to font-size on element');

test(t => {
  const parentDiv = createDiv(t);
  const div = createDiv(t);
  parentDiv.appendChild(div);
  parentDiv.style.fontSize = '10px';

  const animation = div.animate([ { marginLeft: '10em' },
                                  { marginLeft: '20em' } ], 1000);
  animation.currentTime = 500;
  assert_equals(getComputedStyle(div).marginLeft, '150px',
                'Effect value before updating font-size on parent element');
  parentDiv.style.fontSize = '20px';
  assert_equals(getComputedStyle(div).marginLeft, '300px',
                'Effect value after updating font-size on parent element');
}, 'Effect values reflect changes to font-size on parent element');

promise_test(t => {
  const parentDiv = createDiv(t);
  const div = createDiv(t);
  parentDiv.appendChild(div);
  parentDiv.style.fontSize = '10px';
  const animation = div.animate([ { marginLeft: '10em' },
                                  { marginLeft: '20em' } ], 1000);

  animation.pause();
  animation.currentTime = 500;
  parentDiv.style.fontSize = '20px';

  return animation.ready.then(() => {
    assert_equals(getComputedStyle(div).marginLeft, '300px',
                  'Effect value after updating font-size on parent element');
  });
}, 'Effect values reflect changes to font-size when computed style is not'
   + ' immediately flushed');

promise_test(t => {
  const divWith10pxFontSize = createDiv(t);
  divWith10pxFontSize.style.fontSize = '10px';
  const divWith20pxFontSize = createDiv(t);
  divWith20pxFontSize.style.fontSize = '20px';

  const div = createDiv(t);
  div.remove(); // Detach
  const animation = div.animate([ { marginLeft: '10em' },
                                  { marginLeft: '20em' } ], 1000);
  animation.pause();

  return animation.ready.then(() => {
    animation.currentTime = 500;

    divWith10pxFontSize.appendChild(div);
    assert_equals(getComputedStyle(div).marginLeft, '150px',
                  'Effect value after attaching to font-size:10px parent');
    divWith20pxFontSize.appendChild(div);
    assert_equals(getComputedStyle(div).marginLeft, '300px',
                  'Effect value after attaching to font-size:20px parent');
  });
}, 'Effect values reflect changes to font-size from reparenting');

test(t => {
  const divA = createDiv(t);
  divA.style.fontSize = '10px';

  const divB = createDiv(t);
  divB.style.fontSize = '20px';

  const animation = divA.animate([ { marginLeft: '10em' },
                                   { marginLeft: '20em' } ], 1000);
  animation.currentTime = 500;
  assert_equals(getComputedStyle(divA).marginLeft, '150px',
                'Effect value before updating target element');

  animation.effect.target = divB;
  assert_equals(getComputedStyle(divB).marginLeft, '300px',
                'Effect value after updating target element');
}, 'Effect values reflect changes to target element');

</script>
</body>
