@axinom/mosaic-transactional-inbox-outbox/src/outbox/setup-transactional-outbox-listener.ts

This library encapsulates the Mosaic based transactional inbox and outbox pattern

/* eslint-disable @typescript-eslint/explicit-function-return-type */
import { Broker } from '@axinom/mosaic-message-bus';
import {
  GeneralMessageHandler,
  PollingListenerConfig,
  PollingMessageStrategies,
  ReplicationListenerConfig,
  ReplicationMessageStrategies,
  StoredTransactionalMessage,
  initializePollingMessageListener,
  initializeReplicationMessageListener,
} from 'pg-transactional-outbox';
import { InboxOutboxLogger } from '../common';
import { TransactionalLogMapper } from '../transactional-log-mapper';
import { RabbitMqOutboxMetadata } from './setup-outbox-storage';

const setupRabbitMqPublisher = (broker: Broker): GeneralMessageHandler => {
  return {
    handle: async (message: StoredTransactionalMessage): Promise<void> => {
      // Publish a message
      const { envelopeOverrides, options, action } =
        message.metadata as RabbitMqOutboxMetadata;
      (action === 'command' ? broker.publishCommand : broker.publishEvent).call(
        broker,
        message.aggregateId,
        {
          aggregateType: message.aggregateType,
          messageType: message.messageType,
        },
        message.payload,
        envelopeOverrides,
        options,
      );
    },
  };
};

/**
 * Setup the transactional outbox listener to send messages.
 * @param listenerConfig The service configurations
 * @param broker RabbitMQ based messaging broker
 * @param logger A service-common library based logger instance
 * @param config A service-common library based config object
 * @param strategies Optional strategies to customize the outbox message processing
 * @returns shutdown action to stop the outbox listener
 */
export const setupReplicationOutboxListener = (
  listenerConfig: ReplicationListenerConfig,
  broker: Broker,
  logger: InboxOutboxLogger,
  config: { logLevel: string },
  strategies?: ReplicationMessageStrategies,
): (() => Promise<void>) => {
  const transactionalLogger = new TransactionalLogMapper(
    logger,
    config.logLevel,
  );
  const [shutdown] = initializeReplicationMessageListener(
    listenerConfig,
    setupRabbitMqPublisher(broker),
    transactionalLogger,
    strategies,
  );

  return shutdown;
};

/**
 * Setup the transactional outbox listener to send messages.
 * @param listenerConfig The service configurations
 * @param broker RabbitMQ based messaging broker
 * @param logger A service-common library based logger instance
 * @param config A service-common library based config object
 * @param strategies Optional strategies to customize the outbox message processing
 * @returns shutdown action to stop the outbox listener
 */
export const setupPollingOutboxListener = (
  listenerConfig: PollingListenerConfig,
  broker: Broker,
  logger: InboxOutboxLogger,
  config: { logLevel: string },
  strategies?: PollingMessageStrategies,
): (() => Promise<void>) => {
  const transactionalLogger = new TransactionalLogMapper(
    logger,
    config.logLevel,
  );
  const [shutdown] = initializePollingMessageListener(
    listenerConfig,
    setupRabbitMqPublisher(broker),
    transactionalLogger,
    strategies,
  );

  return shutdown;
};