chromium/third_party/blink/web_tests/external/wpt/css/css-display/display-contents-blockify-dynamic.html

<!doctype html>
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1561283">
<link rel="help" href="https://drafts.csswg.org/css-display/#valdef-display-contents">
<link rel="help" href="https://drafts.csswg.org/css-grid/#grid-item-display">
<link rel="author" href="https://mozilla.org" title="Mozilla">
<link rel="author" href="mailto:[email protected]" title="Emilio Cobos Álvarez">
<link rel="author" href="mailto:[email protected]" title="Oriol Brufau">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  .grid { display: grid }
</style>
<div style="display: grid">
  <span id="grid-child">
    <span></span>
  </div>
</div>
<script>
function display(el) {
  return getComputedStyle(el).display;
}
test(function() {
  let child = document.getElementById("grid-child");
  let grandChild = child.firstElementChild;
  assert_equals(display(child), "block", "Grid child should get blockified");
  assert_equals(display(grandChild), "inline", "Grid grand-child should not get initially blockified");
  child.style.display = "contents";
  assert_equals(display(child), "contents", "No reason for it not to become display: contents");
  assert_equals(display(grandChild), "block", "Grid grand-child with display: contents parent should get blockified");
  child.style.display = "";
  assert_equals(display(child), "block", "Grid child should get blockified");
  assert_equals(display(grandChild), "inline", "Grid grand-child should get un-blockified when its parent's display stops being `contents`");
}, "Dynamic changes to `display` causing blockification of children are handled correctly");
</script>