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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /css/css-transitions/animations/color-transition-premultiplied.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>transition from transparent background</title>
<style>
.box {
width: 100px;
height: 100px;
margin: 10px;
border: 1px solid black;
transition: background-color 1s linear;
}
#one {
background-color: transparent;
}
#one.changed {
background-color: green;
}
#two {
background-color: rgba(0, 255, 0, 0);
}
#two.changed {
background-color: rgba(0, 0, 255, 1);
}
</style>
</head>
<body>
<div class="box" id="one"></div>
<div class="box" id="two"></div>
</body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/css-transitions/support/helper.js"></script>
<script type="text/javascript">
promise_test(async t => {
// Make sure we have rendered the page before making the style change
// to ensure we get transitions.
await waitForAnimationFrames(2);
promises = [];
const elem1 = document.getElementById('one');
const elem2 = document.getElementById('two');
elem1.classList.add('changed');
elem2.classList.add('changed');
document.getAnimations().forEach(anim => {
anim.pause();
anim.currentTime = 500;
promises.push(anim.ready);
});
Promise.all(promises).then(() => {
assert_equals(promises.length, 2, 'Unexpected animation count');
assert_equals(getComputedStyle(elem1).backgroundColor,
'rgba(0, 128, 0, 0.5)');
assert_equals(getComputedStyle(elem2).backgroundColor,
'rgba(0, 0, 255, 0.5)');
});
}, 'Transition from transparent background');
</script>
</html>