Source code
Revision control
Copy as Markdown
Other Tools
Test Info:
- This WPT test may be referenced by the following Test IDs:
- /css/css-shadow-parts/host-part-002.html - WPT Dashboard Interop Dashboard
<!DOCTYPE HTML>
<title>CSS Shadow Parts - :host::part() cascading</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="host"></div>
<script>
test(function() {
let host = document.getElementById("host");
let shadow = host.attachShadow({mode: "open"});
// Make three rules with equal specificity, so that they cascade by
// order. Pseudo-elements and elements have the same specificity.
// Pseudo-classes and attribute selectors have the same specificity.
shadow.innerHTML = `
<style>
div[part="part-name"] {
color: red;
}
:host::part(part-name) {
color: lime;
background-color: red;
}
div[part="part-name"] {
background-color: green;
}
</style>
<div part="part-name"></div>
`;
let part_cs = getComputedStyle(shadow.querySelector('div[part="part-name"]'));
assert_equals(part_cs.color, "rgb(0, 255, 0)",
":host::part() selectors override earlier selectors with " +
"same encapsulation context and specificity");
assert_equals(part_cs.backgroundColor, "rgb(0, 128, 0)",
":host::part() selectors are overridden by later selectors " +
"with same encapsulation context and specificity");
}, ":host::part has correct cascading behavior");
</script>