What arguments of TypeOrmModule.forFeature() in TS should be? - module

Question

I am trying to add repositories to my TypeOrmModule.forFeature(), which from what I understood, defines which repositories have been created.
Following the documentation, I saw that we could simply add the entity name, like :
imports: [TypeOrmModule.forFeature([User])],
In another tutorial, I saw someone putting direcly the repository name into forFeature, such as follow :
imports: [TypeOrmModule.forFeature([UserRepository])],
In my current code, I am declaring few entities and repositories. Repositories are created using DataSource, for example :
export const WheelRepository = (src: DataSource) => src.getRepository(Wheel);
However, the only way I could make my code works is this way, which is a mix of two solutions above - while all my entities declarations are strictly similar as the one mentionned above :
(here is a car.module.ts)
#Module({
imports: [TypeOrmModule.forFeature([Car, Wheel, OptionRepository])], /* define repositories */
controllers: [CarController, WheelController, OptionController],
providers: [CarService, WheelService, OptionService],
})
export class CarModule {}
... so by explicitely naming "Repository" for my entity.
While this does not work :
#Module({
imports: [TypeOrmModule.forFeature([Car, Wheel, Option])], /* define repositories */
controllers: [CarController, WheelController, OptionController],
providers: [CarService, WheelService, OptionService],
})
export class CarModule {}
Complete output :
[Nest] 18832 - 2022-06-22 16:34:13 ERROR [ExceptionHandler] Nest can't resolve dependencies of the OptionService (?). Please make sure that the argument OptionRepositoryRepository at index [0] is available in the CarModule context.
Potential solutions:
- If OptionRepositoryRepository is a provider, is it part of the current CarModule?
- If OptionRepositoryRepository is exported from a separate #Module, is that module imported within CarModule?
#Module({
imports: [ /* the Module containing OptionRepositoryRepository */ ]
})
Error: Nest can't resolve dependencies of the OptionService (?). Please make sure that the argument OptionRepositoryRepository at index [0] is available in the CarModule context.
Potential solutions:
- If OptionRepositoryRepository is a provider, is it part of the current CarModule?
- If OptionRepositoryRepository is exported from a separate #Module, is that module imported within CarModule?
#Module({
imports: [ /* the Module containing OptionRepositoryRepository */ ]
})
at Injector.lookupComponentInParentModules (/Users/me/Documents/project_test/node_modules/#nestjs/core/injector/injector.js:231:19)
at process._tickCallback (internal/process/next_tick.js:68:7)
at Function.Module.runMain (internal/modules/cjs/loader.js:757:11)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! project_test#0.0.1 start: `nest start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the project_test#0.0.1 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
I have the same error when I try to change "Wheel" by "WheelRepository" in my list of imports.
I can not understand in which case I should be able to use one or another method, and why in this case I have to mix both.
[ EDIT ]
I found why by comparing files : in my OptionService constructor, I was injecting #InjectRepository(OptionRepository) instead of #InjectRepository(Option).
I am still curious of knowing why this error happens because I do not understand the link between car module, which is like "above", and the injection in the service.

Answer 1

From what I understand from https://docs.nestjs.com/recipes/sql-typeorm and the source of #nestjs/typeorm
TypeOrmModule.forFeature([...Entities]) imports TypeormModule providers coming from TypeormModule.forRoot() and make it available inside service using its provider token string.
import { DataSource } from 'typeorm';
import { Photo } from './photo.entity';
export const photoProviders = [
{
provide: 'PHOTO_REPOSITORY', // provider token string
useFactory: (dataSource: DataSource) => dataSource.getRepository(Photo),
inject: ['DATA_SOURCE'],
},
];
and #InjectRepository(Photo) gives the provider token string and use it like any injectable provider.
export class PhotoService {
constructor(
#Inject('PHOTO_REPOSITORY') //#InjectRepository(Photo)
private photoRepository: Repository<Photo>,
) {}
}
when you put #InjectRepository(OptionRepository) in the constructor. #nestjs/typeorm couldn't resolve its provider token string because OptionRepository wasn't the thing you give to
imports: [TypeOrmModule.forFeature([Car, Wheel, Option])]