How can I dynamically inject different providers with Nest.js? - oop

Question

I'm facing the following issue. I have a service used by a controller. The service (in the snippets below QueueService) injects a provider imported from a package. I aim to reuse the QueueService across the controller methods, but I also need to dynamically specify which provider QueueService should use.
My question is, how can I achieve this behaviour?
import { PubsubService } from '#myorg/queue'
#Module({
imports: [
ConfigModule.forRoot({
SHARED_RESOURCES_PROJECT_ID: Joi.string().required()
})
})
],
controllers: [AppController],
providers: [
{
provide: 'PUBSUB',
useValue: new PubsubService()
},
{
provide: 'INTEGRATION_PUBSUB',
useValue: new PubsubService({ projectId: process.env.SHARED_RESOURCES_PROJECT_ID })
}
]
})
export class AppModule {}
#Controller()
export class AppController {
constructor(private queueService: QueueService) {}
#Post()
async create() {
...
// here I want to use queueService with `PUBSUB` injected
return this.queueService.sendMessage(...)
}
#Patch()
async update() {
...
// here I want to use queueService with `INTEGRATION_PUBSUB` injected
return this.queueService.sendMessage(...)
}
}
#Injectable()
export class QueueService {
constructor(
// how can I dynamically change `#Inject('PUBSUB')` to `#Inject('INTEGRATION_PUBSUB')`?
#Inject('PUBSUB') private readonly pubsubService: PubsubService
) {}
async sendMessage(payload): Promise<void> {
return this.pubsubService.sendMessage(payload)
}
}

Answer 1

dynamic inject is not possible after object(in this case controller) created . so you have two option
1- create two QueueService (one for PUBSUB and another for INTEGRATION_PUBSUB) and inject both to controller. use those in your controller functions. (i recommend this)
2- inject both PUBSUB and INTEGRATION_PUBSUB into QueueService and pass another param in sendMessage function . so check this param to choose between PUBSUB and INTEGRATION_PUBSUB