Import service to another module error

[worthy pawn]

Hey I'm pretty new to the NestJS, can anybody explain me why is this happening?

Error:
Nest can't resolve dependencies of the AuthService (?, JwtService, PrismaService). Please make sure that the argument dependency at index [0] is available in the AuthModule context.

app.module.ts

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
      load: [config],
    }),
    AuthModule,
    PrismaModule,
    UserModule,
   ],
})
export class AppModule {}

user.module.ts

@Module({
  providers: [UserService, PrismaService, AuthService, JwtService],
  controllers: [UserController],
  imports: [TypedEventEmitterModule],
})
export class UserModule {}

user.service.ts

export class AuthService {
  constructor(
    private userService: UserService,
    private jwtService: JwtService,
    private prisma: PrismaService,
  ) {}
}

auth.module.ts

@Module({
  controllers: [AuthController],
  providers: [AuthService, UserService, PrismaService, JwtService],
})
export class AuthModule {}

[low stream]

Suggestion for @worthy pawn:
Don't list a service in providers array of a module unless the module really provides the service.
If your ServiceA depends on a ServiceB from different module ModuleB, add ServiceB to ModuleBs exports array,
then add ModuleB to imports array in your module.

@Module({
  providers: [ServiceB],
  exports: [
    ServiceB // <-- export the "ServiceB" provider by adding it to the module's exports array
  ], 
})
export class ModuleB {}

@Module({
  imports: [
    ModuleB // <-- modules that wish to inject the "ServiceB" will need to import the "ModuleB" in their imports array
  ],  
  providers: [ServiceA],
})
export class ModuleA {}

import { ServiceB } from '../module-b/service-b.service'

@Injectable()
export class ServiceA {
  constructor(private readonly serviceB: ServiceB) {}
  
  // async foo() {
  //   this.serviceB.bar();
  // }
}

[worthy pawn]

I'm really confused, so it should look like this?

app.module.ts

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
      load: [config],
    }),
    AuthModule,
    PrismaModule,
    UserModule,
   ],
})
export class AppModule {}

user.module.ts

@Module({
  providers: [UserService, PrismaService, JwtService], // AuthService deleted
  controllers: [UserController],
  imports: [TypedEventEmitterModule, AuthModule], // AuthModule added

})
export class UserModule {}

user.service.ts

export class AuthService {
  constructor(
    private userService: UserService,
    private jwtService: JwtService,
    private prisma: PrismaService,
  ) {}
}

auth.module.ts

@Module({
  controllers: [AuthController],
  providers: [AuthService, UserService, PrismaService, JwtService], 
  exports: [AuthService], // export AuthService added
})
export class AuthModule {}

[inland mortar]

I think so
what's the error now?

[worthy pawn]

This is the error now: ERROR [ExceptionHandler] Nest can't resolve dependencies of the AuthService (?, JwtService, PrismaService). Please make sure that the argument dependency at index [0] is available in the AuthModule context.

[inland mortar]

have you read this https://docs.nestjs.com/faq/common-errors#cannot-resolve-dependency-error

[worthy pawn]

Yes I was looking that, AuthService provider is already in AuthModule

[inland mortar]

that's not the case

read the docs again

also, this article will help you to understand that error better and fix it: https://trilon.io/blog/avoiding-circular-dependencies-in-nestjs

[worthy pawn]

so there is no actual way to use ServiceA in ModuleB and ServiceB in ModuleA because it is circular error...

[inland mortar]

there is a way
as shown in the docs and in the article above

but I'd suggest you to try to fix the circular import

[worthy pawn]

I manage to fix my problem, thank you for support 🤲