chromium/third_party/blink/web_tests/animations/composition/background-size-composition.html

<!DOCTYPE html>
<meta charset="UTF-8">
<style>
.target {
  background-image: url(), url();
}
</style>
<body>
<script src="../interpolation/resources/interpolation-test.js"></script>
<script>
assertComposition({
  property: 'background-size',
  underlying: '40px 40px',
  addFrom: '60px 60px, 260px 260px',
  addTo: '160px 160px',
}, [
  {at: -0.25, is: '75px 75px, 325px 325px'},
  {at: 0, is: '100px 100px, 300px 300px'},
  {at: 0.25, is: '125px 125px, 275px 275px'},
  {at: 0.5, is: '150px 150px, 250px 250px'},
  {at: 0.75, is: '175px 175px, 225px 225px'},
  {at: 1, is: '200px 200px, 200px 200px'},
  {at: 1.25, is: '225px 225px, 175px 175px'},
]);

assertComposition({
  property: 'background-size',
  underlying: '20% 40%',
  addFrom: '40px 80px, 180% 160%',
  addTo: '80% 40%',
}, [
  {at: -0.25, is: 'calc(50px + 0%) calc(100px + 30%), 225% 230%'},
  {at: 0, is: 'calc(40px + 20%) calc(80px + 40%), 200% 200%'},
  {at: 0.25, is: 'calc(30px + 40%) calc(60px + 50%), 175% 170%'},
  {at: 0.5, is: 'calc(20px + 60%) calc(40px + 60%), 150% 140%'},
  {at: 0.75, is: 'calc(10px + 80%) calc(20px + 70%), 125% 110%'},
  {at: 1, is: '100% 80%, 100% 80%'},
  {at: 1.25, is: 'calc(-10px + 120%) calc(-20px + 90%), 75% 50%'},
]);

assertComposition({
  property: 'background-size',
  underlying: '40px 40px',
  replaceFrom: '100px 100px',
  addTo: '160px 160px',
}, [
  {at: -0.25, is: '75px 75px, 75px 75px'},
  {at: 0, is: '100px 100px, 100px 100px'},
  {at: 0.25, is: '125px 125px, 125px 125px'},
  {at: 0.5, is: '150px 150px, 150px 150px'},
  {at: 0.75, is: '175px 175px, 175px 175px'},
  {at: 1, is: '200px 200px, 200px 200px'},
  {at: 1.25, is: '225px 225px, 225px 225px'},
]);

assertComposition({
  property: 'background-size',
  underlying: '40px 40px',
  addFrom: '60px 60px',
  replaceTo: '200px 200px',
}, [
  {at: -0.25, is: '75px 75px, 75px 75px'},
  {at: 0, is: '100px 100px, 100px 100px'},
  {at: 0.25, is: '125px 125px, 125px 125px'},
  {at: 0.5, is: '150px 150px, 150px 150px'},
  {at: 0.75, is: '175px 175px, 175px 175px'},
  {at: 1, is: '200px 200px, 200px 200px'},
  {at: 1.25, is: '225px 225px, 225px 225px'},
]);

assertComposition({
  property: 'background-size',
  underlying: 'auto, contain',
  addFrom: '100px 150px',
  replaceTo: '200px 250px',
}, [
  {at: -0.25, is: '75px 125px, 75px 125px'},
  {at: 0, is: '100px 150px, 100px 150px'},
  {at: 0.25, is: '125px 175px, 125px 175px'},
  {at: 0.5, is: '150px 200px, 150px 200px'},
  {at: 0.75, is: '175px 225px, 175px 225px'},
  {at: 1, is: '200px 250px, 200px 250px'},
  {at: 1.25, is: '225px 275px, 225px 275px'},
]);

assertComposition({
  property: 'background-size',
  underlying: 'auto 100px, contain',
  addFrom: neutralKeyframe,
  replaceTo: 'auto 200px, contain',
}, [
  {at: -0.25, is: 'auto 75px, contain'},
  {at: 0, is: 'auto 100px, contain'},
  {at: 0.25, is: 'auto 125px, contain'},
  {at: 0.5, is: 'auto 150px, contain'},
  {at: 0.75, is: 'auto 175px, contain'},
  {at: 1, is: 'auto 200px, contain'},
  {at: 1.25, is: 'auto 225px, contain'},
]);
</script>
</body>