编译Nest项目时nest无法解析服务的依赖关系

Question

编译以下代码时出错:我是nestjs新手，这是附带的示例应用程序代码。我也尝试用UsersService替换module.ts中的UsersModule，但它没有起作用。我做错什么了？

 [Nest] 19960 - 10/19/2020, 11:42:09 PM [NestFactory] Starting Nest application...
[Nest] 19960 - 10/19/2020, 11:42:09 PM [InstanceLoader] MongooseModule dependencies initialized +25ms
[Nest] 19960 - 10/19/2020, 11:42:09 PM [InstanceLoader] PassportModule dependencies initialized +1ms
[Nest] 19960 - 10/19/2020, 11:42:09 PM [ExceptionHandler] Nest can't resolve dependencies of the AuthService (?, JwtService). Please make sure that the argument UsersService at index [0] is available in the AuthService context.

Potential solutions:

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

Repoistory：https://github.com/richakhetan/task-manager-nest

Answer 1

模块的结构不适当。我从模块中删除了导致循环依赖的代码，并创建了一个新模块，创建了一个清晰的结构。

详细代码可以在存储库中找到。存储库：https://github.com/richakhetan/task-manager-nest

Answer 2

AuthModule和UserModule 之间有循环依赖关系，UserService和AuthService之间有循环依赖关系。要解决这个问题，您需要在模块和服务上使用forwardRef。一般情况下，这看起来就像

@Module({
  imports: [forwardRef(() => UserModule)],
  providers: [AuthService],
  exports: [AuthService],
})
export class AuthModule {}

@Module({
  imports: [forwardRef(() => AuthModule)],
  providers: [UserService],
  exports: [UserService],
})
export class UserModule {}

@Injectable()
export class AuthService {
  constructor(@Inject(forwardRef(() => UserService)) private readonly userService: UserService) {}
}

@Injectable()
export class UserService {
  cosntructor(@Inject(forwardRef(() => AuthService) private readonly authService: AuthService) {}
}

编辑

忘记添加exports属性