chromium/third_party/blink/web_tests/accessibility/editable-anonymous-block.html

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

<div id="editable" contenteditable="true">
    Hello
  <div>there</div>
</div>

<script>
  test(() => {
    let editable = accessibilityController.accessibleElementById('editable');
    assert_not_equals(editable, null);
    assert_equals(editable.childrenCount, 2);

    let staticText = editable.childAtIndex(0);
    assert_not_equals(staticText, null);
    assert_equals(staticText.role, 'AXRole: AXStaticText');
    assert_equals(staticText.name, 'Hello');
    assert_true(staticText.isEditable);
    assert_true(staticText.isRichlyEditable);
  }, 'This no longer really tests anything');
</script>