Request a file as the document type with asynchronous XMLHttpRequest in a document context. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS req.status is 200 PASS req.response is non-null. PASS result is "PASS" PASS req.status is 200 PASS req.response is non-null. PASS result is "PASS" PASS FAIL req.status is 200 PASS should be 200. Was 0. FAIL req.response is should be non-null. PASS result is "PASS" Was null FAIL Change responseType from blob to document in HEADERS_RECEIVED: Failed: TypeError: Cannot read property 'querySelector' of null PASS successfullyParsed is true TEST COMPLETE