This has to do with how I decided to write the OgmaModule. So each @OgmaModule() is really an alias for @Inject('OGMA_SERVICE:token'). I don't do anything like adding the tokens to an array that gets populated at start time, as I've seen described in some articles, I just make the decorator a simple alias to help keep things simple. So, as @OgmaLogger() is just setting up an injection token, we also need to tell Nest about that injection token, and we can do that using the OgmaModule.forFeature() dynamic module, so that we can set up loggers per feature that we want to use. If you don't want to add the context per logger, you could just inject OgmaService into your constructor and be done with it, but I've found the context per class to be helpful.

I designed it this way to give more clarity into what is being used in the module and less hand-waviness behind the scenes. I generally prefer more explicit config than implicit

Thanks for explanation. 🙏 It makes sense, however, it might be a good idea to explain this in the docs and/or README.md files. Maybe it’s just be not being able to find what I am looking for. 🤷‍♂️

First line of this page

The @ogma/nestjs-module comes with its own decorator to be used with OgmaModule.forFeature(), very similar to @nestjs/typeorm and @nestjs/mongoose. To inject an OgmaService, simply use the @OgmaLogger() decorator and provide the context for the injection

Can I make this clearer somehow?

Well, maybe it’s just me being more of a TS/Nest newbie, but I didn’t get this out of the quoted text from docs.

Based on what I have learnt from chatting with you in this discussion, I would expect to have the following information to be somewhere in there:

• one needs to list all tokens in OgmaModule.forFeature() or OgmaModule.forFeatures() in module file that can be used in that particular module (in any file within that module);
• OgmaModule.forFeature() accepts a single token and OgmaModule.forFeatures() accepts an array of tokens;
• [this is already in the docs] a token specified in @OgmaLogger() in a constructor of a service can be overrided by specifying a context as the second parameter of the log command (e.g. `this.logger.log('message', {context: 'new-token'}).

@jmcdo29, I am here to ask you if it was possible to add support of isGlobal property so that we could make OgmaModule a global module and then we would need to define only OgmaModule.forFeature()/OgmaModule.forFeatures() in other (non-root/sub-) modules.

As I see it, we usually want to have a single logger configuration per app. The logger config is usually dependent on some app config variables (e.g. in .env we define the wanted log level and format).

Now, when I want to use @nestjs/config, I need to add OgmaModule asynchronously:

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
      load: [(): Config => customConfig],
    }),
    OgmaModule.forRootAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => ({
        interceptor: {
          http: FastifyParser,
        },
        isGlobal: true,  // Note: This does not work.
        service: {
          application: 'appName',
          color: true,
          each: true,
          json: false,
          logLevel: configService.get<OgmaOptions['logLevel']>('logLevel'),
        },
      }),
    })
  ]
})

It works in itself, but ConfigModule needs to be imported directly in both root module and any other submodule (otherwise it does not work, even though ConfigModule is imported in the root module), which makes it non-DRY. However, I think Ogma users should be able to defined the Ogma logger config once per app, in order to deduplicate the configuration.

In the end, I don’t want to import ConfigModule nor OgmaModule.forRootAsync() in any of the submodules, as they are already configured in the root module.

Update: Actually, it works without CacheModule being imported in the submodules, but I need to remove it from the imports of OgmaModule.forRootAsync() too, like so:

@Module({
  imports: [
    OgmaModule.forRootAsync({
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => ({
        interceptor: {
          http: FastifyParser,
        },
        isGlobal: true,  // Note: This does not work.
        service: {
          application: 'appName',
          color: true,
          each: true,
          json: false,
          logLevel: configService.get<OgmaOptions['logLevel']>('logLevel'),
        },
      }),
    })
  ]
})

Update 2: Actually, it seems to work. I missed ConfigService provider in the service file test; when I added it, it all works as expected. Sorry for the noise.