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

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[ ] Regression 
[ x] Bug report
[ ] Feature request
[ ] Documentation issue or request
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Current behavior

I get :

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

Expected behavior

The app should run and the AuthService dependancies can be injected in AuthModule

Minimal reproduction of the problem with instructions

app.module.ts

@Module({
    imports: [
        TypeOrmModule.forRoot(),
        UserModule,
        AuthModule
    ],
    controllers: [AppController, UserController],
    providers: [AppService, UserService],
})
export class AppModule {
    constructor(private readonly connection: Connection) {

    }
}

auth.module.ts :

@Module({
    imports: [UserModule],
    providers: [AuthService, HttpStrategy]
})
export class AuthModule {
}

http.strategy.ts :

@Injectable()
export class HttpStrategy extends PassportStrategy(Strategy) {
    constructor(private readonly authService: AuthService) {
        super();
    }

    async validate(token: string) {
        const user = await this.authService.validateUser(token);
        if (!user) {
            throw new UnauthorizedException();
        }
        return user;
    }
}

auth.service.ts :

@Injectable()
export class AuthService {
    constructor(private readonly userService: UserService) {}

    async validateUser(token: string): Promise<any> {
        // Validate if token passed along with HTTP request
        // is associated with any registered account in the database
        return await this.userService.findOneByToken(token);
    }
}

What is the motivation / use case for changing the behavior?

I want to add an Authentication system in my app.

Environment

Nest version: 5.4.0

 
For Tooling issues:
- Node version: 10.15.0  
- Platform: Windows  

[underfisk]

Hi, i think you are missing the export of the provider (you are trying to use the service in a different module) I have ran into the same issue before

[frenchqwerty]

My issues is solved ! The solution is : auth.module.ts :

@Module({
    imports: [
        UserModule,
        PassportModule.register({defaultStrategy: 'bearer'})
],
    providers: [AuthService, HttpStrategy, UserService]
})
export class AuthModule {
}

Just add the UserService in provider.