async activate()

in lib/eventstream_rpc.ts [918:958]
31 lines of code
3 McCabe index (conditional complexity)

    async activate() : Promise<ResponseType> {
        return new Promise<ResponseType>(async (resolve, reject) => {
            try {
                let stream : eventstream.ClientStream = this.operation.getStream();
                stream.addListener(eventstream.ClientStream.MESSAGE, this._onStreamMessageEvent.bind(this));
                stream.addListener(eventstream.ClientStream.ENDED, this._onStreamEndedEvent.bind(this));

                let responsePromise : Promise<eventstream.Message> = cancel.newCancellablePromiseFromNextEvent({
                    cancelController: this.operationConfig.options.cancelController,
                    emitter : stream,
                    eventName : eventstream.ClientStream.MESSAGE,
                    eventDataTransformer: (eventData: any) => {
                        this.responseHandled = true;
                        return (eventData as eventstream.MessageEvent).message;
                        },
                    cancelMessage: "Eventstream execute() cancelled by user request"
                });


                let requestMessage: eventstream.Message = serializeRequest(this.serviceModel, this.operationConfig.name, this.request);
                await this.operation.activate(requestMessage);

                let message : eventstream.Message = await responsePromise;
                let response : ResponseType = deserializeResponse(this.serviceModel, this.operationConfig.name, message);

                // If the server terminated the stream, then set the operation to be ended immediately
                if ((message.flags ?? 0) & eventstream.MessageFlags.TerminateStream) {
                    this.operation.setStateEnded();
                    // Server hung up on us. Immediately cleanup the operation state.
                    // Do this before resolving the promise so that any user-initiated
                    // requests will see the correct state, which is that the operation is closed.
                    await this.close();
                }

                resolve(response);
            } catch (e) {
                await this.close();
                reject(e);
            }
        });
    }