Method send

packages/nodebox/src/messages.ts:300–364

(
    event: Event,
    ...data: ConsumerEvents[Event] extends [infer PayloadType, infer _]
      ? [PayloadType]
      : ConsumerEvents[Event] extends Record<string, unknown>
      ? [ConsumerEvents[Event]]
      : [undefined?]
  )

  }

  public async send<Event extends keyof ConsumerEvents & string>(
    event: Event,
    ...data: ConsumerEvents[Event] extends [infer PayloadType, infer _]
      ? [PayloadType]
      : ConsumerEvents[Event] extends Record<string, unknown>
      ? [ConsumerEvents[Event]]
      : [undefined?]
  ): Promise<
    ConsumerEvents[Event] extends [infer _, infer ReturnType] ? OperationEvent<ReturnType> | undefined : void
  > {
    const operationPromise = new DeferredPromise<
      ConsumerEvents[Event] extends [infer _, infer ReturnType] ? OperationEvent<ReturnType> : void
    >();
    const operationId = cuid();

    const payload = data[0] || {};
    debug('[message-sender]: send "%s" (%s)', event, operationId, payload);

    this.receiverPort.postMessage({ type: event, payload: { operationId, payload } });

    // Await this operation to be confirmed as done by the receiver.
    debug('[message-sender]: adding done listener for "%s" (%s)', event, operationId);

    const handleOperationDone = (doneEvent: MessageEvent<WorkerEvents['internal/operation/done']>) => {
      const { data } = doneEvent;

      if (data.operationId === operationId) {
        const listenerPayload = (data.listenerPayload || {}) as ConsumerEvents[Event] extends [
          infer _,
          infer ReturnType
        ]
          ? OperationEvent<ReturnType>
          : void;

        debug('[message-sender]: resolving "%s (%s) promise!', event, operationId);

        operationPromise.resolve({
          ...listenerPayload,
          operationId: data.operationId,
        });
      }
    };

    const handleOperationFailed = (failEvent: MessageEvent<WorkerEvents['internal/operation/failed']>) => {
      const { data } = failEvent;

      if (data.operationId === operationId) {
        debug('[message-sender]: rejecting "%s (%s) promise!', event, operationId);

        operationPromise.reject(data.error);
      }
    };

    this.on('internal/operation/done', handleOperationDone);

    // Handle exceptions from the receiver.
    this.on('internal/operation/failed', handleOperationFailed);