<!DOCTYPE html>
<title>Test that non-transitioned style is responsive to transitioning properties</title>
<link rel="help" href="https://drafts.csswg.org/css-transitions/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#target1 {
transition: font-size steps(2, start) 1000s;
font-size: 10px;
width: 1em;
}
#target1.change {
font-size: 20px;
}
#ref1 {
width: 15px;
}
#target2 {
transition: font-size steps(2, start) 1000s;
font-size: 10px;
width: 1ex;
}
#target2.change {
font-size: 20px;
}
#ref2 {
font-size: 15px;
width: 1ex;
}
#target3 {
transition: --x steps(2, start) 1000s;
--x: 10px;
width: var(--x);
}
#target3.change {
--x: 20px;
font-size: 20px;
}
#ref3 {
width: 20px;
}
</style>
<div id="targets">
<div id="target1"></div>
<div id="target2"></div>
<div id="target3"></div>
</div>
<div id="refs">
<div id="ref1"></div>
<div id="ref2"></div>
<div id="ref3"></div>
</div>
<script>
// Test that the computed value of the given property is equal on
// 'target' and 'ref', after applying the transition to 'target'.
function test_ref(target, ref, property, description) {
test(() => {
let unused = getComputedStyle(target).getPropertyValue(property);
target.className = 'change';
let actual = getComputedStyle(target).getPropertyValue(property);
let expected = getComputedStyle(ref).getPropertyValue(property);
assert_equals(actual, expected);
}, description);
}
test_ref(target1, ref1, 'width', 'em units respond to font-size transition');
test_ref(target2, ref2, 'width', 'ex units respond to font-size transition');
test_ref(target3, ref3, 'width', 'var() references respond to custom property transition');
</script>
Codebase Browser
chromium