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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /css/css-cascade/layer-cssom-order-reverse.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<title>CSS Cascade Layers: at-rule and style invalidation on layer order changes</title>
<link rel="author" href="mailto:xiaochengh@chromium.org">
<link rel="stylesheet" href="/fonts/ahem.css">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#reference {
color: green;
font: 20px/1 ahem;
width: max-content;
}
</style>
<div id=target>Lorem ipsum</div>
<div id=reference>Lorem ipsum</div>
<script>
const testCases = [
{
title: 'Insert layer invalidates style',
sheets: [
'',
`
@layer first {
#target { color: green; }
}
@layer second {
#target { color: red; }
}
`,
],
update: function(sheets) {
sheets[0].insertRule('@layer second {}', 0);
},
property: 'color',
},
{
title: 'Delete layer invalidates style',
sheets: [
'@layer second {}',
`
@layer first {
#target { color: red; }
}
@layer second {
#target { color: green; }
}
`,
],
update: function(sheets) {
sheets[0].deleteRule(0);
},
property: 'color',
},
{
title: 'Insert layer invalidates @font-face',
sheets: [
'',
`
@layer first {
@font-face {
font-family: custom;
src: local('Ahem'), url('/fonts/Ahem.ttf');
}
}
@layer second {
@font-face {
font-family: custom;
src: url('/fonts/noto/noto-sans-v8-latin-regular.woff') format('woff');
}
}
#target { font: 20px/1 custom; width: max-content; }
`,
],
update: async function(sheets) {
await document.fonts.load('20px/1 ahem');
await document.fonts.load('20px/1 custom');
document.body.offsetLeft; // Force style recalc
sheets[0].insertRule('@layer second {}', 0);
await document.fonts.load('20px/1 custom');
},
property: 'width',
},
{
title: 'Delete layer invalidates @font-face',
sheets: [
'@layer second {}',
`
@layer first {
@font-face {
font-family: custom;
src: url('/fonts/noto/noto-sans-v8-latin-regular.woff') format('woff');
}
}
@layer second {
@font-face {
font-family: custom;
src: local('Ahem'), url('/fonts/Ahem.ttf');
}
}
#target { font: 20px/1 custom; width: max-content; }
`,
],
update: async function(sheets) {
await document.fonts.load('20px/1 ahem');
await document.fonts.load('20px/1 custom');
document.body.offsetLeft; // Force style recalc
sheets[0].deleteRule(0);
await document.fonts.load('20px/1 custom');
},
property: 'width',
},
];
for (let testCase of testCases) {
promise_test(async test => {
const styleElements = testCase.sheets.map(sheet => {
const element = document.createElement('style');
element.appendChild(document.createTextNode(sheet));
document.head.appendChild(element);
return element;
});
test.add_cleanup(() => {
for (let element of styleElements)
element.remove();
});
const sheets = styleElements.map(element => element.sheet);
await testCase.update(sheets);
const actual = getComputedStyle(target).getPropertyValue(testCase.property);
const expected = getComputedStyle(reference).getPropertyValue(testCase.property);
assert_equals(actual, expected);
}, testCase.title);
}
</script>