Node.js 如何取笑模拟nestjs导入？

我想为我的nestjs“Course”存储库服务（一个依赖于Mongoose模型和Redis的服务）编写一个单元测试

courses.repository.ts：

    import { Injectable, HttpException, NotFoundException } from "@nestjs/common";
    import { InjectModel } from "@nestjs/mongoose"
    import { Course } from "../../../../shared/course";
    import { Model } from "mongoose";
    import { RedisService } from 'nestjs-redis';


    @Injectable({}) 
    export class CoursesRepository {

      private redisClient;
      constructor(
        @InjectModel('Course') private courseModel: Model<Course>,
        private readonly redisService: RedisService,
      ) {
        this.redisClient = this.redisService.getClient();

      }


      async findAll(): Promise<Course[]> {
        const courses = await this.redisClient.get('allCourses');
        if (!courses) {
          console.log('return from DB');
          const mongoCourses = await this.courseModel.find();
          await this.redisClient.set('allCourses', JSON.stringify(mongoCourses), 'EX', 20);
          return mongoCourses;
        }

        console.log('return from cache');
        return JSON.parse(courses);
      }
}

我可以创建一个模拟的Redis服务，在测试期间使用它来代替实际的Redis服务吗

怎么做

谢谢，

---

Yaron

你可以模仿你的

再服务

，就像其他依赖一样。因为您真正感兴趣的是Redis客户端而不是服务，所以必须为服务创建一个中间模拟。对于mongoose，您需要

getModelToken

方法来获取正确的注入令牌，请参见以下内容：

还请注意，您可能不应该在单元测试中导入模块（除非它是测试模块）。有关单元测试和e2e测试之间的区别，请参见此

如何创建模拟？

---

看看这个。

你能显示你的

课程的代码吗？
beforeEach(async () => {
  const moduleRef = await Test.createTestingModule({
    imports: [
      MongooseModule.forRoot(MONGO_CONNECTION,  { 
        useNewUrlParser: true,
        useUnifiedTopology: true
      }),
      MongooseModule.forFeature([
        { name: "Course", schema: CoursesSchema },
        { name: "Lesson", schema: LessonsSchema }
      ]),
      RedisModule.register({})
    ],
      controllers: [CoursesController, LessonsController],
      providers: [
         CoursesRepository,
         LessonsRepository
        ],
    }).compile();

  coursesRepository = moduleRef.get<CoursesRepository>(CoursesRepository);
  redisClient = moduleRef.get<RedisModule>(RedisModule);

});

providers: [
    {provide: CoursesRepository, useFactory: mockCoursesRepository},
     LessonsRepository
    ],

const redisClientMockFactory = // ...
const redisServiceMock = {getClient: () => redisClientMockFactory()}

providers: [
  { provide: RedisService, useValue: redisServiceMock },
  { provide: getModelToken('Course'), useFactory: courseModelMockFactory },
  CoursesRepository
],