<!DOCTYPE html>
<meta charset="UTF-8">
<title>font-size interpolation</title>
<link rel="help" href="https://drafts.csswg.org/css-fonts-3/#propdef-font-size">
<meta name="assert" content="font-size supports animation as length">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/interpolation-testcommon.js"></script>

<style>
.parent {
  font-size: 30px;
}
.target {
  display: inline-block;
  font: 10px sans-serif;
}
.expected {
  color: green;
  margin-right: 30px;
}
</style>

<body>
<template id="target-template">
  <span>
    <div class="target">Test Text</div>
  </span>
</template>
</body>

<script>
test_interpolation({
  property: 'font-size',
  from: neutralKeyframe,
  to: '20px',
}, [
  {at: -2, expect: '0px'},
  {at: -0.3, expect: '7px'},
  {at: 0, expect: '10px'},
  {at: 0.3, expect: '13px'},
  {at: 0.6, expect: '16px'},
  {at: 1, expect: '20px'},
  {at: 1.5, expect: '25px'},
]);

test_interpolation({
  property: 'font-size',
  from: 'initial',
  to: '20px',
}, [
  {at: -2, expect: '8px'},
  {at: -0.3, expect: '14.8px'},
  {at: 0, expect: '16px'},
  {at: 0.3, expect: '17.2px'},
  {at: 0.6, expect: '18.4px'},
  {at: 1, expect: '20px'},
  {at: 1.5, expect: '22px'},
]);

test_interpolation({
  property: 'font-size',
  from: 'inherit',
  to: '20px',
}, [
  {at: -2, expect: '50px'},
  {at: -0.3, expect: '33px'},
  {at: 0, expect: '30px'},
  {at: 0.3, expect: '27px'},
  {at: 0.6, expect: '24px'},
  {at: 1, expect: '20px'},
  {at: 1.5, expect: '15px'},
]);

test_interpolation({
  property: 'font-size',
  from: 'unset',
  to: '20px',
}, [
  {at: -2, expect: '50px'},
  {at: -0.3, expect: '33px'},
  {at: 0, expect: '30px'},
  {at: 0.3, expect: '27px'},
  {at: 0.6, expect: '24px'},
  {at: 1, expect: '20px'},
  {at: 1.5, expect: '15px'},
]);

test_interpolation({
  property: 'font-size',
  from: '4px',
  to: '14px'
}, [
  {at: -2, expect: '0px'},  // CSS font-size can't be negative.
  {at: -0.3, expect: '1px'},
  {at: 0, expect: '4px'},
  {at: 0.3, expect: '7px'},
  {at: 0.6, expect: '10px'},
  {at: 1, expect: '14px'},
  {at: 1.5, expect: '19px'},
]);
</script>
