testing - 试图用 Jest 测试我的嵌套 api，返回未定义

Question

我正在尝试使用 NestJs 框架创建 Jest 测试。

测试应检查 Controller 和服务，但是 1) Controller 未定义，2) 服务未定义。

这是我的home-cards.controller.spec.ts中的代码:

describe('HomeCardsController', () => {
    let homeCardsController: HomeCardsController;
    let homeCardsService: HomeCardsService;

    beforeEach(async () => {
        const module = await Test.createTestingModule({
            imports: [TypeOrmModule.forFeature([HomeCard])],
            controllers: [HomeCardsController],
            providers: [HomeCardsService]
        }).compile();

        homeCardsController = module.get<HomeCardsController>(HomeCardsController);
        homeCardsService = module.get<HomeCardsService>(HomeCardsService);
    });

    describe('findall', () => {
        it('should return an array of home cards', async () => {
            expect( await homeCardsController.findAll(1000)).toBeInstanceOf(Array);
        });
    });
});

错误:

Controller 请求用户的新错误:

TypeError: Cannot read property 'clientId' of undefined

      17 |   async findAll(@Req() request): Promise<HomeCard[]> {
      18 |       const user: AuthUser = request.user;
    > 19 |       return await this.homeCardsService.findAll(user.clientId);
         |                                                       ^
      20 |   }
      21 | 
      22 |   @Get(":id")

Answer 1

您必须模拟调用 HomeCardsController 的 HomeCardsService 方法

import { HomeCardService } from './home-cards.service.ts'; // your path to service
jest.mock('./home-cards.service.ts'); // your path to service

describe('HomeCardsController', () => {
    let homeCardsController: HomeCardsController;
    let homeCardsService: HomeCardsService;

    beforeEach(async () => {
        const module = await Test.createTestingModule({
            // imports: [TypeOrmModule.forFeature([HomeCard])], <- unit test don't need database, mock all
            controllers: [HomeCardsController],
            providers: [HomeCardsService]
        }).compile();

        homeCardsController = module.get<HomeCardsController>(HomeCardsController);
        homeCardsService = module.get<HomeCardsService>(HomeCardsService);
    });

    describe('findall', () => {
        it('should return an array of home cards', async () => {
            const result = []; // some result for mock method
            jest.spyOn(homeCardsService, 'findAll').mockImplementation(() => result);
            const request = {user: {clientId: 1000}}
            expect( await homeCardsController.findAll(request)).toBeInstanceOf(Array);
        });
    });
});