Nodejs Jest 单元测试无法从 Mongodb 内部返回值 find, findOne答案

【问题标题】：Nodejs Jest Unit testing unable to return value from inside Mongodb find, findOneNodejs Jest 单元测试无法从 Mongodb 内部返回值 find, findOne
【发布时间】：2019-05-18 18:59:31
【问题描述】：

我正在使用 console.log(data);但它甚至不从 findOne 方法内部返回 req.params._id 但它从 findOne 方法外部返回

unitMethodTest = async (req, res, next) => {
    await this.model.findOne({ _id: req.params._id }).exec((err, data) => {
        if (err) {
            console.log('===++++++ failed ');
            return req.params._id;
        }
        else {
            console.log(' Ok ')
            // console.log(data);  
            return req.params._id;  // Getting Error <--
        }
    });
  // return req.params._id; // Test--2 Working fine <--
}

这里是我的测试代码：-

const req = {
  params: { _id: '5cc14019fa1c2c68ee7e17f9', },
  body: 'body'
 }, next = 'next', res = 'response';

  test('First Method Testing Demo for req.params and req.body', () => {
  // expect.assertions(1);
  const dataTest = controller.unitMethodTest(req, res, next);
  console.log(dataTest);
  // console.log(dataTest);
   expect(dataTest).toEqual("5cc14019fa1c2c68ee7e17f9");    
  })

我得到如下输出

   expect(received).toEqual(expected) // deep equality

Expected: "5cc14019fa1c2c68ee7e17f9"
Received: {}

  53 |       // console.log(dataTest);
  54 |       // // const dataTest = 11257;
> 55 |        expect(dataTest).toEqual("5cc14019fa1c2c68ee7e17f9");
     |                         ^
  56 |        done();
  57 |       // return controller.unitMethodTest(req, res, next).catch(e => expect(e).toEqual("5cc14019fa1c2c68ee7e17f9"));
  58 |    })

  at Object.<anonymous> (server/unitTesting/caseload.test.ts:55:25)

 console.log server/unitTesting/caseload.test.ts:52
Promise { <pending> }

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total
Snapshots:   0 total
Time:        18.606s

Cannot log after tests are done. Did you forget to wait for something 
async in your test?
Attempted to log " Ok ".

【问题讨论】：

标签： node.js unit-testing testing jestjs

【解决方案1】：

unitMethodTest 是 async，所以你必须在测试中使用 await 它，正如 Jest 在报告末尾告诉你的那样。

test('First Method Testing Demo for req.params and req.body', async () => {
  const dataTest = await controller.unitMethodTest(req, res, next);
  expect(dataTest).toEqual("5cc14019fa1c2c68ee7e17f9");    
})

注意第一行的async

【讨论】：