css/css-contain/content-visibility/content-visibility-054.html

<!doctype HTML>
<html>
<meta charset="utf8">
<title>Display Locking: focus on styled element</title>
<link rel="author" title="Rakina Zata Amni" href="mailto:rakina@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
<meta name="assert" content="focus does not target display-none but hidden elements">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<div id="container" style="content-visibility: auto">
  <div id="focusable1" tabIndex="0">
    focusable thing
  </div>
  <div id="displayNoneParent">
    <div id="focusable2" tabIndex="0">
      focusable thing
    </div>
  </div>
</div>

<script>
test(() => {
  focusable1.style.display = "none";
  focusable1.focus();
  assert_not_equals(document.activeElement, focusable1);

  displayNoneParent.style.display = "none";
  focusable2.focus();
  assert_not_equals(document.activeElement, focusable2);
}, "Trying to focus on an element in a hidden subtree with display none will not work");
</script>
</html>