Jest 和 Typescript：无法检查对象是否是类的实例

问题描述

我需要检查该方法是否正在返回一个类的实例，但我在这里有点迷茫。 我在运行测试时得到 ReferenceError。

Mapper.spec.js：

import { SetConfigurationRequestModel } from '../../usecases/Models/SetConfigurationRequestModel'
import { ISetConfigurationRequest } from '../requests/ISetConfigurationRequest'
import { Mapper } from './Mapper'

describe('Helpers/Mappers',() => {
  describe('cfgRequest2RequestModel',() => {
    test('should exist',() => {
      const sut = new Mapper()
      expect(sut.cfgRequest2RequestModel).toBeTruthy()
    })
    test('should be a method',() => {
      const sut = new Mapper()
      expect(typeof sut.cfgRequest2RequestModel).toBe('function')
    })
    test('should return a RequestModel',() => {
      const sut = new Mapper()
      const fakeRequest = makeFakeRequest()
      const requestModel = sut.cfgRequest2RequestModel(fakeRequest)
      expect(requestModel).toBeInstanceOf(SetConfigurationRequestModel)
    })
  })
})

Mapper.js：

import { SetConfigurationRequestModel } from '../../usecases/Models/SetConfigurationRequestModel'
import { ISetConfigurationRequest } from '../requests/ISetConfigurationRequest'

export class Mapper {
  cfgRequest2RequestModel (request: ISetConfigurationRequest): object {
    const request2 = new SetConfigurationRequestModel()
    return request2
  }
}

玩笑输出：

FAIL  src/delivery/helpers/mappers.spec.ts
  ● Helpers/Mappers › cfgRequest2RequestModel › should return a RequestModel

    ReferenceError: SetConfigurationRequestModel is not defined

      4 | export class Mapper {
      5 |   cfgRequest2RequestModel (request: ISetConfigurationRequest): object {
    > 6 |     const request2 = new SetConfigurationRequestModel()
        |                      ^
      7 |     return request2
      8 |   }
      9 | }

      at Mapper.cfgRequest2RequestModel (src/delivery/helpers/Mapper.ts:6:22)
      at Object.<anonymous> (src/delivery/helpers/mappers.spec.ts:42:32)```

解决方法

问题与代码无关。

以防万一有人遇到同样的情况，请在 jest 命令中添加 --no-cache 选项。