node.js - loopback 4中如何编写单元测试用例

Question

我是 loopback 4 的新手。我想为我的项目编写单元测试用例。但是，我找不到他们使用模拟服务和使用 stub 的适当示例。

请协助我或分享任何正确编写的单元测试示例(使用模拟服务和 stub )。

谢谢

下面是我的代码库:

Controller

export class CaptureController {
  constructor(
    @inject(RestBindings.Http.RESPONSE) private response: Response,
    @service(HelperService) private helperService: HelperService,
  ) { }
@post('/capture', {
    'x-controller-name': CaptureSwagger.controller,
    summary: CaptureSwagger.summary,
    description: CaptureSwagger.description,
    responses: {
      '200': CaptureSuccess.response,
      '400': CommonHttpErrors(Messages.badRequest, 400, ''),
      '401': CommonHttpErrors(
        Messages.unauthorized,
        401,
        Messages.unauthorized,
      ),
    },
  })
  async capture(
    @requestBody() body: Capture,
  ): Promise<Response> {
    const response = await this.helperService
      .getGatewayService()
      .capture(body);
    const data = this.helperService.getGatewayKeys(
      response,
      TransactionType.COMPLETE,
    );

    const buildResponse = BuildResponse.prepare({data});
    return this.response.json(buildResponse);
  }
}

HelperService

@injectable({scope: BindingScope.TRANSIENT})
export class HelperService {
  constructor(
    @inject(RestBindings.Http.CONTEXT) private context: RequestContext,
    @service(ConvergeService) private convergeService: ConvergeService,  
   ) { }
getGatewayService() {
    const merchantGateway: MerchantGateway =
      this.context.getSync('merchantGateway');
    const gatewayName: PaymentGateway | string = merchantGateway?.sysName
      ? merchantGateway.sysName
      : '';
    switch (gatewayName.toLowerCase()) {
      case PaymentGateway.CONVERGE:
        return this.convergeService;
      default:
        return this.nexioService;
    }
  }
}

融合服务

@injectable({scope: BindingScope.TRANSIENT})
export class ConvergeService {
/**
   * Capture
   * @param body Capture payment
   */
  public capture = async (body: Capture) => {
    const startAt = process.hrtime();
    let errorResp = '';
    const captureXml = `${this.xmlData}<ssl_transaction_type>cccomplete</ssl_transaction_type>
    <ssl_amount>${body.data.amount}</ssl_amount>
    <ssl_txn_id>${body.id}</ssl_txn_id>
    </txn>`;
    try {
      const resp: {data: string} = await axiosApi.post(
        `${this.convergeObj.apiUrl}`,
        captureXml,
      );
      const jsonResp = this.parseXmlToJson(resp.data);

      if (jsonResp?.txn?.errorCode) {
        errorResp = resp.data;
        throw new ResponseError.BadRequest(jsonResp.txn.errorMessage);
      }
      return jsonResp.txn ? jsonResp.txn : jsonResp;
    } catch (err) {
      this.commonService.getErrorResponse(err);
    }
  };
}

Answer 1

我将分享一个示例。我认为您可以为您的服务定制它。我们假设，我们有这样的汽车服务和简单​​的价格计算器功能:

@injectable({scope: BindingScope.TRANSIENT})
export class CarService {
constructor(
  @repository(CarRepository)
  private carRepository: CarRepository,
) {}

  async calculateCarPricesWithTaxes(tax: number): Promise<[]> {
    const cars = await this.carRepository.find({where: {price: {gte: 10000}}});

    return cars.map(car => (car.price * tax / 100) + car.price);
  }
}

这个服务的单元测试类是这样的:

describe('CarService', () => {  

  let carRepository: StubbedInstanceWithSinonAccessor<CarRepository>;

  beforeEach(() => {
    carRepository = createStubInstance(CarRepository);

    carService = new CarService(carRepository);
  });

  after(() => {
    sinon.restore();
  });

  describe('calculateCarPricesWithTaxes', () => {
    it('should get new prices for cars', async () => {
      const find = carRepository.stubs.find;
      find.resolves([
        {id: 1, price: 10000},
        {id: 1, price: 20000},
      ]);

      const res = await carService.calculateCarPricesWithTaxes(10);

      expect(res).to.eql([11000, 22000]);
      // expect(res).to.not.eql([110, 220]);

      sinon.assert.calledWith(find, {where: {price: {gte: 10000}}});

      // sinon.assert.calledOnce(find);
    });
  });
});

希望对你有帮助