chromium/third_party/blink/web_tests/animations/interpolation/svg-stop-opacity-interpolation.html

<!DOCTYPE html>
<meta charset="UTF-8">
<style>
.container {
  display: inline-block;
}
.parent {
  stop-opacity: 0.8;
}
.target {
  stop-opacity: 0.6;
}
</style>
<body>
<template id="target-template">
  <svg width="10" height="100">
    <defs>
      <linearGradient id="gradient" x1="0" x2="0" y1="0" y2="1">
        <stop offset="0" stop-color="black"/>
        <stop offset="1" stop-color="blue" class="target"/>
      </linearGradient>
    </defs>
    <rect x="0" y="0" width="10" height="100" fill="url(#gradient)"></rect>
  </svg>
</template>
<script src="resources/interpolation-test.js"></script>
<script>
assertInterpolation({
  property: 'stop-opacity',
  from: neutralKeyframe,
  to: '0.4',
}, [
  {at: -0.4, is: '0.68'},
  {at: 0, is: '0.6'},
  {at: 0.2, is: '0.56'},
  {at: 0.6, is: '0.48'},
  {at: 1, is: '0.4'},
  {at: 1.5, is: '0.3'},
]);

assertInterpolation({
  property: 'stop-opacity',
  from: 'initial',
  to: '0.4',
}, [
  {at: -0.4, is: '1'},
  {at: 0, is: '1'},
  {at: 0.2, is: '0.88'},
  {at: 0.6, is: '0.64'},
  {at: 1, is: '0.4'},
  {at: 1.5, is: '0.1'},
]);

assertInterpolation({
  property: 'stop-opacity',
  from: 'inherit',
  to: '0.4',
}, [
  {at: -0.4, is: '0.96'},
  {at: 0, is: '0.8'},
  {at: 0.2, is: '0.72'},
  {at: 0.6, is: '0.56'},
  {at: 1, is: '0.4'},
  {at: 1.5, is: '0.2'},
]);

assertInterpolation({
  property: 'stop-opacity',
  from: 'unset',
  to: '0.4',
}, [
  {at: -0.4, is: '1'},
  {at: 0, is: '1'},
  {at: 0.2, is: '0.88'},
  {at: 0.6, is: '0.64'},
  {at: 1, is: '0.4'},
  {at: 1.5, is: '0.1'},
]);

assertInterpolation({
  property: 'stop-opacity',
  from: '0',
  to: '1',
}, [
  {at: -0.4, is: '0'},
  {at: 0, is: '0'},
  {at: 0.2, is: '0.2'},
  {at: 0.6, is: '0.6'},
  {at: 1, is: '1'},
  {at: 1.5, is: '1'}
]);
</script>
</body>