| Ensures that insertBefore() throws an exception if mutation even handler does something wrong | |
| On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". | |
| PASS newparent.insertBefore(child, beforeChild); threw exception HierarchyRequestError: Failed to execute 'insertBefore' on 'Node': The new child element contains the parent.. | |
| PASS successfullyParsed is true | |
| TEST COMPLETE | |