Make sure that event targets do not get cleared after dispatching an event at the node that was not in a shadow tree but gets moved into a shadow tree by an event listener. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS window.event is e PASS counter++ is 0 PASS window.event is e PASS counter++ is 1 PASS window.event is e PASS counter++ is 2 PASS counter is 3 PASS event.target is child PASS event.relatedTarget is document.body PASS successfullyParsed is true TEST COMPLETE