Nestjs override base service method-CodePudding

I have the following method inside a base service:

crud-base.service.ts

export class CrudBaseService {
  constructor(protected repo: MongoRepository<any>) {}
  
  async create(data) {
    // do stuff
  }
}

Here I want to be able to create my custom create method so I name my method the same as the one from base service

items.service.ts

@Injectable()
export class ItemsService extends CrudBaseService {
  constructor(
    @InjectRepository(Item)
    private itemsRepository: MongoRepository<Item>,
  ) {
    super(itemsRepository);
  }
}

async create(data) {
    // overriding base service method
}

Gives me the following error:

TS2416: Property 'create' in type 'ItemsService' is not assignable to the same property in base type 'CrudBaseService'

CodePudding user response：

The signature of both functions must be the same, that means parameters and return type must be the same. You should make this explicit.

export class CrudBaseService {
  constructor(protected repo: MongoRepository<any>) {}
  
  async create(data: YourType): Promise<YourReturnType> {
    // do stuff
  }
}


@Injectable()
export class ItemsService extends CrudBaseService {
  constructor(
    @InjectRepository(Item)
    private itemsRepository: MongoRepository<Item>,
  ) {
    super(itemsRepository);
  }
}

// this should work
async create(data: YourType): Promise<YourReturnType> {
    // overriding base service method
}