How to implement repository design pattern for MongoDB on NestJS

Question

I'm trying to figuring out how to implement repository design pattern on NestJS that using MongoDB and mongoose database

Answer 1

Repository could be injected into the service and it should be included in providers array within the module.

// user.service.ts
@Injectable()
export class UserService {
  constructor(private readonly userRepository: UserRepository) {}

  async findAll(): Promise<User[]> {
    return this.userRepository.findAll();
  }
}

// user.repository.ts
@Injectable()
export class UserRepository {
  constructor(@InjectModel(User.name) private userModel: Model<UserDocument>) {}

  async findAll(): Promise<User[]> {
    return this.userModel.find().exec();
  }
}

// user.module.ts
@Module({
  imports: [
    MongooseModule.forFeature([{ name: User.name, schema: UserSchema }]),
  ],
  providers: [UserRepository, UserService],
  exports: [UserService],
})
export class UserModule {}