// This script provides an object with common message subjects to assist main // and worker thread communication. const messageSubject = { ERROR: "error", // info field may contain more detail OBJECT_URL: "object url", // info field contains object URL HANDLE: "handle", // info field contains the MediaSourceHandle STARTED_BUFFERING: "started buffering", FINISHED_BUFFERING: "finished buffering", VERIFY_DURATION: "verify duration", // info field contains expected duration AWAIT_DURATION: "await duration", // wait for element duration to match the expected duration in the info field VERIFY_HAVE_NOTHING: "verify have nothing readyState", VERIFY_AT_LEAST_HAVE_METADATA: "verify readyState is at least HAVE_METADATA", ACK_VERIFIED: "verified", // info field contains the message values that requested the verification WORKER_DONE: "worker done", // this lets worker signal main to successfully end the test };