chromium/third_party/blink/web_tests/editing/inserting/editable-inline-element.html

<!doctype HTML>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../assert_selection.js"></script>
<script>
selection_test(
  '<span contenteditable>|foo</span>',
  'insertParagraph',
  '<span contenteditable><br>|foo</span>',
  'InsertParagraph in inline element');
</script>