export function onMessagePublished()

in src/v2/providers/pubsub.ts [101:185]
73 lines of code
2 McCabe index (conditional complexity)

export function onMessagePublished<T = any>(
  topic: string,
  handler: (event: CloudEvent<MessagePublishedData<T>>) => any | Promise<any>
): CloudFunction<MessagePublishedData<T>>;

/** Handle a message being published to a Pub/Sub topic. */
export function onMessagePublished<T = any>(
  options: PubSubOptions,
  handler: (event: CloudEvent<MessagePublishedData<T>>) => any | Promise<any>
): CloudFunction<MessagePublishedData<T>>;

export function onMessagePublished<T = any>(
  topicOrOptions: string | PubSubOptions,
  handler: (event: CloudEvent<MessagePublishedData<T>>) => any | Promise<any>
): CloudFunction<MessagePublishedData<T>> {
  let topic: string;
  let opts: options.EventHandlerOptions;
  if (typeof topicOrOptions === 'string') {
    topic = topicOrOptions;
    opts = {};
  } else {
    topic = topicOrOptions.topic;
    opts = { ...topicOrOptions };
    delete (opts as any).topic;
  }

  const func = (raw: CloudEvent<unknown>) => {
    const messagePublishedData = raw.data as {
      message: unknown;
      subscription: string;
    };
    messagePublishedData.message = new Message(messagePublishedData.message);
    return handler(raw as CloudEvent<MessagePublishedData<T>>);
  };

  func.run = handler;

  Object.defineProperty(func, '__trigger', {
    get: () => {
      const baseOpts = options.optionsToTriggerAnnotations(
        options.getGlobalOptions()
      );
      const specificOpts = options.optionsToTriggerAnnotations(opts);

      return {
        // TODO(inlined): Remove "apiVersion" once the CLI has migrated to
        // "platform"
        apiVersion: 2,
        platform: 'gcfv2',
        ...baseOpts,
        ...specificOpts,
        labels: {
          ...baseOpts?.labels,
          ...specificOpts?.labels,
        },
        eventTrigger: {
          eventType: 'google.cloud.pubsub.topic.v1.messagePublished',
          resource: `projects/${process.env.GCLOUD_PROJECT}/topics/${topic}`,
        },
      };
    },
  });

  const baseOpts = options.optionsToEndpoint(options.getGlobalOptions());
  const specificOpts = options.optionsToEndpoint(opts);

  const endpoint: ManifestEndpoint = {
    platform: 'gcfv2',
    ...baseOpts,
    ...specificOpts,
    labels: {
      ...baseOpts?.labels,
      ...specificOpts?.labels,
    },
    eventTrigger: {
      eventType: 'google.cloud.pubsub.topic.v1.messagePublished',
      eventFilters: { topic },
      retry: false,
    },
  };
  copyIfPresent(endpoint.eventTrigger, opts, 'retry', 'retry');
  func.__endpoint = endpoint;

  return func;
}