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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /css/cssom/CSSStyleSheet-constructable-duplicate.html - WPT Dashboard Interop Dashboard
<!doctype html>
<title>Cascade order of a stylesheet for duplicate sheets.</title>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<script src = '/resources/testharness.js'></script>
<script src = '/resources/testharnessreport.js'></script>
<div id="target"></div>
<script>
function attachShadowDiv(host) {
const shadowRoot = host.attachShadow({mode: 'open'});
const shadowDiv = document.createElement("div");
shadowRoot.appendChild(shadowDiv);
return shadowDiv;
}
function blueSheetsWithIncreasingZIndex(n) {
let sheets = [];
for (let i = 0; i < n; ++i) {
sheets.push(new CSSStyleSheet());
sheets[i].replaceSync("div { z-index: " + i + "; color: blue; }");
}
return sheets;
}
let sheets = [];
test(function() {
sheets = blueSheetsWithIncreasingZIndex(2);
document.adoptedStyleSheets = [sheets[1], sheets[0], sheets[1]];
assert_equals(getComputedStyle(document.querySelector("div")).zIndex, "1", "duplicate stylesheet should take right position in the cascade");
document.adoptedStyleSheets = [];
}, "Duplicate stylesheets have the right cascade position in the Document");
test(function() {
sheets = blueSheetsWithIncreasingZIndex(2);
const sheet = new CSSStyleSheet();
sheet.replaceSync("div { color: red; }");
document.adoptedStyleSheets = [sheets[1], sheets[0]];
assert_equals(getComputedStyle(document.querySelector("div")).zIndex, "0", "backmost stylesheet should take precedence");
assert_equals(getComputedStyle(document.querySelector("div")).color, "rgb(0, 0, 255)", "backmost stylesheet should take precedence");
document.adoptedStyleSheets = [sheets[1], sheets[0], sheets[1], sheet];
assert_equals(getComputedStyle(document.querySelector("div")).zIndex, "1", "duplicate stylesheet should take the right position in the cascade");
assert_equals(getComputedStyle(document.querySelector("div")).color, "rgb(255, 0, 0)", "backmost stylesheet should take precedence");
document.adoptedStyleSheets = [];
}, "Appending duplicate stylesheets yields the correct cascade position in the Document");
test(function() {
sheets = blueSheetsWithIncreasingZIndex(2);
const span = document.createElement("span");
target.appendChild(span);
attachShadowDiv(span);
span.shadowRoot.adoptedStyleSheets = [sheets[1], sheets[0], sheets[1]];
assert_equals(getComputedStyle(span.shadowRoot.querySelector("div")).zIndex, "1", "duplicate stylesheet should take right position in the cascade");
}, "Duplicate stylesheets have the right cascade position in the ShadowRoot");
test(function() {
sheets = blueSheetsWithIncreasingZIndex(2);
const sheet = new CSSStyleSheet();
sheet.replaceSync("div { color: red; }");
const span = document.createElement("span");
target.appendChild(span);
attachShadowDiv(span);
span.shadowRoot.adoptedStyleSheets = [sheets[1], sheets[0]];
assert_equals(getComputedStyle(span.shadowRoot.querySelector("div")).zIndex, "0", "backmost stylesheet should take precedence");
assert_equals(getComputedStyle(span.shadowRoot.querySelector("div")).color, "rgb(0, 0, 255)", "backmost stylesheet should take precedence");
span.shadowRoot.adoptedStyleSheets = [sheets[1], sheets[0], sheets[1], sheet];
assert_equals(getComputedStyle(span.shadowRoot.querySelector("div")).zIndex, "1", "duplicate stylesheet should take right position in the cascade");
assert_equals(getComputedStyle(span.shadowRoot.querySelector("div")).color, "rgb(255, 0, 0)", "backmost stylesheet should take precedence");
}, "Appending duplicate stylesheets yields the correct cascade position in the ShadowRoot");
</script>