how to resolve problem whem import repository in nestjs - many-to-many

Question

im new in nestjs and i have one problem when i try to export my custom Repository, i dont any idea about how to resolve it.
gas-station.repository.ts i create custom repository:
#Injectable()
class GasStationRepository implements IGasStationRepository {
constructor(
#InjectRepository(GasStation)
private readonly gasStationRepository: Repository<GasStation>,
) {}
//...
public async createGasStation(
gasStationDto: ICreateGasStationDto,
): Promise<GasStation> {
const gasStation = this.gasStationRepository.create(gasStationDto);
await this.gasStationRepository.save(gasStation);
return gasStation;
}
public async bulkCreateGasStation(
gasStations: ICreateGasStationDto[],
): Promise<GasStation[]> {
return Promise.all(gasStations.map(this.createGasStation));
}
}
export default GasStationRepository;
gas-station.module.ts i thin it is normal formule to export my repository:
#Module({
imports: [TypeOrmModule.forFeature([GasStation])],
controllers: [GasStationController],
providers: [
GasStationService,
{
useClass: GasStationRepository,
provide: GAS_STATION_REPOSITORY,
},
],
exports: [
{
useClass: GasStationRepository,
provide: GAS_STATION_REPOSITORY,
},
],
})
export class GasStationModule {}
user.module.ts i import gasStationModule for use repository
#Module({
imports: [TypeOrmModule.forFeature([User]), GasStationModule],
controllers: [UserController],
providers: [
UserService,
{
useClass: UserRepository,
provide: USER_REPOSITORY,
},
],
})
export class UserModule {}
user.service.ts i will use repository :
#Injectable()
export class UserService {
constructor(
#Inject(USER_REPOSITORY) private readonly userRepository: IUserRepository,
#Inject(GAS_STATION_REPOSITORY)
private readonly gasStationRepository: IGasStationRepository,
) {}
async create(createUserDto: CreateUserDto) {
const {
type,
branches,
gasStations,
email,
password,
...props
} = createUserDto;
const existedUser = await this.userRepository.findByEmail(email);
if (existedUser) {
throw new BadRequestException('Usuário já cadastrado');
}
let gasStationList: ICreateGasStationDto[] = [];
let branchList: ICreateBranchDto[] = [];
if (type === 1 && gasStations && gasStations.length > 0) {
gasStationList = await this.gasStationRepository.bulkCreateGasStation(
gasStations,
);
} else if (type === 2 && branches && branches.length > 0) {
branchList = [];
}
const hashedPassword = await hash(password, 8);
const user = await this.userRepository.createUser({
type,
email,
password: hashedPassword,
...(branchList.length > 0 && { branches: branchList }),
...(gasStationList.length > 0 && { gasStations: gasStationList }),
...props,
active: false,
} as ICreateUserDto);
delete user.password;
return user;
}
//...
}
ERROR:
TypeError: Cannot read property 'gasStationRepository' of undefined
at createGasStation (/media/michelkuguio/Novo volume/easypetro/nest/epetro/dist/modules/gas-station/gas-station.repository.js:30:33)
at Array.map (<anonymous>)
at GasStationRepository.bulkCreateGasStation (/media/michelkuguio/Novo volume/easypetro/nest/epetro/dist/modules/gas-station/gas-station.repository.js:35:40)
at UserService.create (/media/michelkuguio/Novo volume/easypetro/nest/epetro/dist/modules/user/user.service.js:45:62)
at processTicksAndRejections (internal/process/task_queues.js:93:5)
at async /media/michelkuguio/Novo volume/easypetro/nest/epetro/node_modules/#nestjs/core/router/router-execution-context.js:46:28
at async /media/michelkuguio/Novo volume/easypetro/nest/epetro/node_modules/#nestjs/core/router/router-proxy.js:9:17
[Nest] 9228 - 19/04/2021 08:42:22 [HttpExceptionFilter] Http Status: 500 Error Message: {} +13880ms

Answer 1

The issue is in your bulkCreateGassStation method. gasStations.map(this.createGasStations) doesn't preserve the context where it is called from. You can either .bind(this) and set the context to be properly bound, or you can gasStations.map(station => this.createStations(station))