async activate()

in lib/eventstream_rpc.ts [740:775]
30 lines of code
5 McCabe index (conditional complexity)

    async activate(message: eventstream.Message) : Promise<OperationActivationResult> {
        return new Promise<OperationActivationResult>(async (resolve, reject) => {
            if (this.state != OperationState.None) {
                reject(createRpcError(RpcErrorType.ClientStateError, "Eventstream operations may only have activate() invoked once"));
                return;
            }

            this.state = OperationState.Activating;

            try {
                let activatePromise = this.stream.activate({
                    operation : this.operationConfig.name,
                    message : message,
                    cancelController : this.operationConfig.options.cancelController
                });

                await activatePromise;
            } catch (e) {
                if (this.state == OperationState.Activating) {
                    this.state = OperationState.Ended;
                    setImmediate(() => { this.close(); });
                }

                reject(createRpcError(RpcErrorType.InternalError, "Operation stream activation failure", e as CrtError));
                return;
            }

            if (this.state != OperationState.Activating) {
                reject(createRpcError(RpcErrorType.InternalError, "Operation stream activation interruption"));
                return;
            }

            this.state = OperationState.Activated;
            resolve({});
        });
    }