chromium/third_party/blink/web_tests/editing/undo/paste_with_mutation_event_undo_order.html

<!doctype html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../assert_selection.js"></script>
<script>
// Regression test for crbug.com/685975

test(() => {
  assert_not_equals(window.testRunner, undefined,
                    'This test requires testRunner');

  assert_selection(
    [
      '<div contenteditable id="div1">|</div>',
      '<div contenteditable id="div2">bar</div>'
    ].join(''),
    (selection, testRunner) => {
      const document = selection.document;
      const source = document.getElementById('source');
      const div1 = document.getElementById('div1');
      const div2 = document.getElementById('div2');
      div1.addEventListener('DOMNodeInserted', () => {
        div2.focus();
        document.execCommand('selectAll');
        document.execCommand('delete');
      });

      selection.setClipboardData('foo');
      testRunner.execCommand('paste'); // Must be user-initiated paste.
      document.execCommand('undo');
    },
    [
      '<div contenteditable id="div1">foo</div>',
      '<div contenteditable id="div2">^bar|</div>'
    ].join(''));
}, 'Undo ordering maintained when pasting triggers another command with mutation event.');
</script>