Typescript NATS Jetstream PullSubscribe Wildcard

Question

I'm trying to create a nats consumer class that can listen to a stream subject that contains a wildcard.

I was familiar with nats-streaming but since they decided to deprecate it for Jestream, I'm totally lost.

For example I have a publisher, which seems to work, that pushes messages to a Subject.Foo.Bar stream.

I want my consumer to listen on Subject.* and get all the nested messages.

  import moment from 'moment';
  import { consumerOpts, JetStreamPullSubscription, JsMsg, Msg, StringCodec } from 'nats';

  import { IEvent } from '../events/event';
  import { NatsClient } from './nats-client';

  export abstract class NatsNestedListener<S extends IEvent>
  {
    abstract onMessage(data: S['data'], msg: JsMsg): Promise<void>;
    abstract subject: S['subject'];  
    
    private client: NatsClient;
    
    protected subscription: JetStreamPullSubscription;

    constructor(client: NatsClient)
    {
      this.client = client;
    }

    private subscriptionOptions()
    {
      const options = consumerOpts();

      options.ackWait(5000);
      options.deliverAll();
      options.startSequence(1);
      options.durable(this.client.QueueGroupName);
      options.manualAck();

      return options;
    }

    async listen()
    {
      // Creates Stream if not exists
      await this.client.initStream(`${this.subject}.*`);

      this.subscription = await this.client.JetStreamClient.pullSubscribe(`${this.subject}.*`, { ...this.subscriptionOptions() });
      this.subscription.pull({ batch: 0 });
    
      for await(const jsMessage of this.subscription)
      {
        console.log('Message Received', `[Subject]: ${jsMessage.subject} - [Seq]: ${jsMessage.seq}`);

        this.processMessage(jsMessage);
        this.subscription.pull({ batch: 0 });
      }   
    }

    parseMessage(msg: JsMsg | Msg)
    {
      const stringCodec = StringCodec();
      const decodedData = stringCodec.decode(msg.data)

      return JSON.parse(decodedData);
    }

    async processMessage(msg: JsMsg)
    {
      const data = this.parseMessage(msg);
      this.onMessage(data, msg);
    }
  }

I tried to pullSubscribe to Subject.* Subject.> but none of these solutions worked.

Typescript NATS Jetstream PullSubscribe Wildcard

0 Answers0