Test window.dispatchEvent(). On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS window.dispatchEvent(event) threw exception Error: UNSPECIFIED_EVENT_TYPE_ERR: DOM Events Exception 0. PASS window.dispatchEvent(event) threw exception Error: UNSPECIFIED_EVENT_TYPE_ERR: DOM Events Exception 0. PASS myEventDispatched is true PASS target is window PASS currentTarget is window PASS useCaptureDispatched is true PASS nonUseCaptureDispatched is true PASS successfullyParsed is true TEST COMPLETE