Interceptors feature about cqrs

[MateuszNaKodach]

@underfisk You can implement it by yourself and also improve your design by reducing coupling between your code and NestJS in Ports&Adapters architecture manner. You can see my repository:
https://github.com/CodersCrew/coders-board-v2
In this directory you have common interface for DomainEventPublisher and two implementations Logging (which is logging interceptor) and NestJS (which use provided by cqrs EventBus).
https://github.com/CodersCrew/coders-board-v2/tree/master/backend/src/write-side/shared-kernel/infrastructure/domain-event-publisher

The provider for the EventBus looks like this:

{
      provide: EXTERNAL_EVENT_PUBLISHER,
      inject: [EventBus, EVENT_STORAGE],
      useFactory: (eventBus: EventBus, eventStorage: EventStorage) =>
        new LoggingExternalEventPublisher(
          new StoreInEventStorageAndForwardExternalEventBus(
            eventStorage,
            new NestJsExternalEventPublisher(eventBus),
          ),
        ),
    }

I hope that this approach will help you :)

[underfisk]

@nowakprojects Well it ain't much what i was looking for because i had already created a custom logging interceptor but it would require manually firing it from the events and what i'm looking for is the nestjs interceptor because i want it to be invoked the same way as HTTP, before and after the event is published
In the idea you gave me, it's also possible but i would have to be injecting it all the time manually which time i create a new domain and if possible having a globalInterceptor would be much better
I'm probably confused but i'm not sure yet how i can achive the tracking of event lifecyle

[kamilmysliwiec]

We don't plan to add another abstraction layer on top of the CQRS module. If you simply want to inspect & subscribe to all events/commands/queries, you can subscribe to the QueryBus/CommandBus/EventBus streams since they extend the Observable. However, the ability to "intercept" objects on the fly is not possible (unless you swap the underlying publisher).

[underfisk]

@kamilmysliwiec Thanks, what i was looking for is not intercept on the fly, it's to gather information about the event processing (when it starts, when it ends and measure some other metrics) but i think if i add a layer to subscribe everything as you said i might do it