css/css-multicol/animation/column-width-interpolation.html

<!DOCTYPE html>
<meta charset="UTF-8">
<title>column-width interpolation</title>
<link rel="help" href="https://drafts.csswg.org/css-multicol-1/#cw">
<meta name="assert" content="column-width supports animation by computed value type">

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

<style>
.parent {
  column-width: 30px;
}
.target {
  font-size: 0px; /* column-width "specified values must be greater than 0", so use font-size to achieve 0px computed value. */
  display: inline-block;
  column-width: 10px;
}
</style>

<body>
<template id="target-template">
  <div><div class="transformed"></div></div>
</template>
</body>

<script>
test_interpolation({
  property: 'column-width',
  from: neutralKeyframe,
  to: '20px',
}, [
  {at: -20, expect: '1em'}, // column-width does not accept negative values
  {at: -1, expect: '1em'}, // column-width does not accept negative values
  {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_no_interpolation({
  property: 'column-width',
  from: 'initial',
  to: '20px',
});

test_interpolation({
  property: 'column-width',
  from: 'inherit',
  to: '20px',
}, [
  {at: -20, expect: '230px'},
  {at: -1, expect: '40px'},
  {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_no_interpolation({
  property: 'column-width',
  from: 'unset',
  to: '20px',
});

test_interpolation({
  property: 'column-width',
  from: '50px',
  to: '100px',
}, [
  {at: -20, expect: '1em'}, // column-width does not accept negative values
  {at: -1, expect: '1em'}, // column-width does not accept negative values
  {at: -0.3, expect: '35px'},
  {at: 0, expect: '50px'},
  {at: 0.3, expect: '65px'},
  {at: 0.6, expect: '80px'},
  {at: 1, expect: '100px'},
  {at: 1.5, expect: '125px'},
]);

test_no_interpolation({
  property: 'column-width',
  from: '50px',
  to: 'auto',
});
</script>