Nest can't resolve dependencies of Service

Question

I'm trying to write a test for service with the mock repository (typeorm), like it provided in nestjs documentation. But there is nothing even good with my testing skills, I guess

Simple service like this one apex.service.ts

@Injectable()
export class ApexService {
private _kafkaClient: ClientKafka;

constructor(
    private readonly _apexRepository: ApexRepository,
    private readonly _kafkaProducer: KafkaProducer,
    private readonly _someService: SomeService,
  ) {}
 // ... code here
}

... and test for it apex.spec.ts

// ... imports

export type MockType<T> = {
  [P in keyof T]?: jest.Mock<{}>;
};

export const repositoryMockFactory: () => MockType<Repository<any>> = jest.fn(
  () => ({
    findOne: jest.fn((entity) => entity),
    create: jest.fn((entity) => entity.id),
    save: jest.fn((entity) => entity.id),
    // ...
  }),
);

describe('ApexService', () => {
  let service: ApexService;
  let repositoryMock: MockType<Repository<CompanyEntity>>;

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [
        ApexService,
        {
          provide: getRepositoryToken(CompanyEntity),
          useFactory: repositoryMockFactory,
        },
        PKUchetProducer,
      ],
    }).compile();
    service = module.get<ApexService>(ApexService);
    repositoryMock = module.get(getRepositoryToken(CompanyEntity));
  });

  it('should create company', async () => {
    const dto = {
      bin: '00000000000',
    };

    const company = {
      id: 0,
    };

    repositoryMock.create.mockReturnValue(company);
    expect(async () => service.createCompany(dto)).toEqual({
      data: 0,
      statusCode: 200,
    });
  });
});

But when I run the test appear this error:

● ApexService › should create company

    Nest can't resolve dependencies of the ApexService (?, KafkaProducer, SomeService). Please make sure that the argument ApexRepository at index [0] is available in the RootTestModule context.

apex.respository.ts

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Company } from '../../shared/domain/company';
import { ICompany } from '../../shared/domain/interfaces/company.interface';
import { Repository } from 'typeorm';
import { CompanyEntity } from '../entities/company.entity';
import { IApexRepository } from '../interfaces/apex-repository.interface';

@Injectable()
export class ApexRepository implements IApexRepository {
  private _apexRepository: Repository<CompanyEntity>;

  constructor(
    @InjectRepository(CompanyEntity)
    private readonly apexRepository: Repository<CompanyEntity>,
  ) {
    this._apexRepository = this.apexRepository;
  }

  public async getCompanyByBIN(bin: string): Promise<Company> {
    const company = await this._apexRepository.findOne({
      where: { bin },
    });

    return Company.transform(company);
  }

  public async createCompany(props: ICompany): Promise<number> {
    const company = this._apexRepository.create(Company.create(props));
    return company.id;
  }

  public async updateCompany(props: ICompany): Promise<number> {
    const company = await this._apexRepository.save(Company.transform(props));
    return company.id;
  }
}

What is the problem, please, explain...

Answer 1

change getRepositoryToken(CompanyEntity) to getRepositoryToken(ApexRepository)

EDIT:

as your repository class isn't a custom repository but rather an standard provider, you must register it in your providers list:

      providers: [
        ApexService,
        {
          provide: getRepositoryToken(CompanyEntity),
          useFactory: repositoryMockFactory,
        },
        { provide: ApexRepository, useValue: yourStub },
        PKUchetProducer,
      ],