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

<!DOCTYPE html>
<meta charset="UTF-8">
<style>
:root {
  font-size: 30px;
}
.parent {
  font-size: 20px;
}
</style>
<body>
<script src="../interpolation/resources/interpolation-test.js"></script>
<script>
assertComposition({
  property: 'font-size',
  underlying: '50px',
  addFrom: '100px',
  addTo: '200px',
}, [
  {at: -0.3, is: '120px'},
  {at: 0, is: '150px'},
  {at: 0.25, is: '175px'},
  {at: 0.5, is: '200px'},
  {at: 0.75, is: '225px'},
  {at: 1, is: '250px'},
  {at: 1.5, is: '300px'},
]);

assertComposition({
  property: 'font-size',
  underlying: '100px',
  addFrom: '10px',
  addTo: 'large',
}, [
  {at: -0.5, is: '106px'},
  {at: 0, is: '110px'},
  {at: 0.25, is: '112px'},
  {at: 0.5, is: '114px'},
  {at: 0.75, is: '116px'},
  {at: 1, is: '118px'},
  {at: 1.5, is: '122px'},
]);

assertComposition({
  property: 'font-size',
  underlying: '50%',
  addFrom: 'small',
  addTo: '20px',
}, [
  {at: -0.3, is: '20.9px'},
  {at: 0, is: '23px'},
  {at: 0.25, is: '24.75px'},
  {at: 0.5, is: '26.5px'},
  {at: 0.75, is: '28.25px'},
  {at: 1, is: '30px'},
  {at: 1.5, is: '33.5px'},
]);

assertComposition({
  property: 'font-size',
  underlying: '20%',
  addFrom: '10rem',
  replaceTo: '5em',
}, [
  {at: -0.3, is: '365.2px'},
  {at: 0, is: '304px'},
  {at: 0.25, is: '253px'},
  {at: 0.5, is: '202px'},
  {at: 0.75, is: '151px'},
  {at: 1, is: '100px'},
  {at: 1.5, is: '0px'},
]);

assertComposition({
  property: 'font-size',
  underlying: 'small',
  replaceFrom: 'medium',
  addTo: 'larger',
}, [
  {at: -0.3, is: '9.7px'},
  {at: 0, is: '16px'},
  {at: 0.25, is: '21.25px'},
  {at: 0.5, is: '26.5px'},
  {at: 0.75, is: '31.75px'},
  {at: 1, is: '37px'},
  {at: 1.5, is: '47.5px'},
]);
</script>
</body>