javascript - Nestjs:将提供者注入(inject)到由关键字 new 创建的对象中

Question

我正在尝试将提供程序注入(inject)到由 new 创建的对象中。是否可以？例如:

@Injectable()
export class SomeService {
}

export class SomeObject {

@Inject()
service: SomeService;
}

let obj = new SomeObject();

它在我的测试中不起作用，obj.service 未定义。

Answer 1

不，依赖注入(inject)系统仅适用于用它创建的对象。 您可以将 SomeObject 创建为 custom provider不过，例如与useClass:

@Injectable()
class SomeObject {
  constructor(private someService: SomeService) {}
}

@Module({
  providers: [
   SomeService,
   { provide: SomeObject, useClass: SomeObject },
  ],
})
export class ApplicationModule {}

或使用 useFactory 进行自定义设置逻辑:

const someObjectFactory = {
  provide: 'SomeObject',
  useFactory: (someService: SomeService) => {
    // custom setup logic
    return new SomeObject(someService);
  },
  inject: [SomeService],
};

@Module({
  providers: [SomeService, connectionFactory],
})
export class ApplicationModule {}