NestJS 无法解析模块内部的依赖关系

Question

我有两个模块：AuthModule 和 UserModule；

这是UserModule 的样子：

@Module({
    imports: [
        forwardRef(() => AuthModule),
        TypeOrmModule.forFeature([
            UserRepository,
            UserAuthRepository,
            UserSocialRepository,
        ])
    ],
    controllers: [UserController],
    exports: [UserAuthService, UserSocialService, UserService],
    providers: [UserAuthService, UserSocialService, UserService],
})
export class UserModule {}

此模块有 3 个服务：UserAuthService、UserSocialService 和 UserService。

内容UserAuthService：

@Injectable()
export class UserAuthService {

    /**
     * UserAuthService constructor
     * @param { UserAuthRepository } _userAuthRepository
     * @param { UserRepository } _userRepository
     * @param { UserService } _userService
     * @param { UserSocialService } _userSocialService
     */
    constructor(
        private readonly _userAuthRepository: UserAuthRepository,
        private readonly _userRepository: UserRepository,
        private readonly _userService: UserService,
        private readonly _userSocialService: UserSocialService
    ) {}
}

内容UserSocialService：

@Injectable()
export class UserSocialService {

    /**
     * UserSocialService constructor
     * @param { UserSocialRepository } _userSocialRepository
     */
    constructor(
        private readonly _userSocialRepository: UserSocialRepository,
    ) {}
}

内容UserService：

@Injectable()
export class UserService {

    /**
     * UserService constructor
     * @param { UserRepository } _userRepository
     * @param { UserAuthService } _userAuthService
     * @param { UserSocialService } _userSocialService
     */
    constructor(
        private readonly _userRepository: UserRepository,
        private readonly _userAuthService: UserAuthService,
        private readonly _userSocialService: UserSocialService
    ) {}
}

AuthModule 和 UserModule 都有 forwardRef(() => Module) 导入，因为它们都相互依赖。

但是，问题出在UserModule 内部，更具体地说是UserService，由于某种原因它无法解决UserAuthService 依赖项，从而产生以下错误：

Error: Nest can't resolve dependencies of the UserService (UserRepository, ?, UserSocialService). Please make sure that the argument dependency at index [1] is available in the UserModule context.

Potential solutions:
- If dependency is a provider, is it part of the current UserModule?
- If dependency is exported from a separate @Module, is that module imported within UserModule?
  @Module({
    imports: [ /* the Module containing dependency */ ]
  })

这是UserModule的结构：

user/
    controllers/
    dtos/
    exceptions/
    models/
    repositories/
    services/
        - index.ts
        - user.auth.service.ts
        - user.service.ts
        - user.social.service.ts
    subscribers/
    -index.ts

因此，即使所有 3 项服务都在一个模块中，并且它们被导出并标记为提供者，NestJS 也由于某种原因无法解析它们。

Answer 1

我不是 100% 确定，但我认为您需要使用 @InjectRepository 注入存储库，就像在 example 中所做的那样：

@Injectable()
export class UserAuthService {

    constructor(
        @InjectRepository(UserAuthRepository)
        private readonly _userAuthRepository: UserAuthRepository,
        @InjectRepository(UserRepository)
        private readonly _userRepository: UserRepository,
        private readonly _userService: UserService,
        private readonly _userSocialService: UserSocialService
    ) {}
}

Answer 2

您的UserService 和UserAuthService 之间存在循环依赖关系。这两个服务都应该使用@Inject(forwardRef(() => OtherService)) 来确保即使通过循环依赖也可以进行注入。

一般来说，如果可能的话，你应该尽量避免这些类相互依赖，这是否意味着打破类的范围并让它只访问必要的内容，或者将这些类合并在一起很难说。

@Injectable()
export class UserService {
  constructor(
    @InjectRepository(UserRepository)
    private readonly _userRepo: UserRepository,
    @Inject(forwardRef(() => UserAuthService))
    private readonly _userAuthService: UserAuthService,
    private readonly _userSocialService: UserSocialService
  ) {}
}

@Injectable()
export class UserAuthService {
  constructor(
    @InjectRepository(UserAuthRepository)
    private readonly _userAuthRepository: UserAuthRepository,
    @InjectRepository(UserRepoitory)
    private readonly _userRepository: UserRepository,
    @Inject(forwardref(() => UserSerivce))
    private readonly _userService: UserService,
    private readonly _userSocialService: UserSocialService
  ) {}
}