added reason to close event

Author: briancbarrow

src/transcription/liveTranscription.ts

@@ -36,6 +36,9 @@ export class LiveTranscription extends EventEmitter {
     };
 
     this._socket.onclose = (event: WebSocket.CloseEvent) => {
+      const newTarget: any = event.target;
+      const dgErrorIndex = newTarget["_req"].res.rawHeaders.indexOf("dg-error");
+      event.reason = newTarget["_req"].res.rawHeaders[dgErrorIndex + 1];
       this.emit(LiveTranscriptionEvents.Close, event);
     };