Injected services are undefined

[pitazzo]

Hey there,
I've tried to implement the basic example provided in the README file, but wherever I inject a service in my code, it's resolved as undefined. No error messages nor warnings are displayed.

Here is my app.module.ts:

@Module({
  imports: [
    GraphQLFederationModule.forRoot({
      context: ({ req }) => ({
        uid: req.headers.uid,
        role: req.headers.role,
      }),
      typePaths: ['./**/*.graphql'],
      resolvers: { Upload: GraphQLUpload },
      definitions: {
        path: join(process.cwd(), 'src/graphql.ts'),
      },
    }),
    DevicesModule,
    FirebaseAdminModule.forRootAsync({
      useFactory: () => ({
        credential: admin.credential.applicationDefault()
      })
    }),
    SecretsModule.forRoot({
      keyFilename: process.env.GOOGLE_APPLICATION_CREDENTIALS,
      projectId: process.env.GCP_PROJECT_ID,
      env: process.env.ENVIRONMENT === 'DEV' ? 'DEV' : 'PROD',
    }),
    SetupModule,
  ],
  providers: [],
})
export class AppModule {}

This is the service where I try to inject the Firebase Services:

export class SetupService {
  constructor(
    private database: FirebaseDatabaseService,
    private storage: FirebaseStorageService,
  ) {}

  async foo(bar: string): Promise<boolean> {
    console.log(this.database) // prints undefined
    // ...
  }
}

This is the module where my service is contained:

@Module({
    providers: [SetupResolver, SetupService]
})
export class SetupModule {}

Is there anything wrong with my code that I'm not able to see?

[pitazzo]

I forgot adding @Injectable() in my service, 100% my fault