getComputedStyle-display-none-003.html

<!doctype html>
<title>style is invalidated properly as a result of attribute changes in display: none subtrees</title>
<link rel="help" href="https://drafts.csswg.org/cssom/#dom-window-getcomputedstyle">
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:[email protected]">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<style>
div {
  color: red
}
.foo {
  color: lime;
}
</style>
<div style="display: none">
  <div id="undisplayed"></div>
</div>
<script>
  test(function() {
    let undisplayed_style = getComputedStyle(undisplayed);
    assert_equals(undisplayed_style.color, "rgb(255, 0, 0)");
    undisplayed.classList.add("foo");
    assert_equals(undisplayed_style.color, "rgb(0, 255, 0)");
  }, "getComputedStyle gets invalidated in display: none subtrees due to attribute mutations");
</script>

chromium/third_party/blink/web_tests/external/wpt/css/cssom/getComputedStyle-display-none-003.html