Mock lodash .isEqual Nodejs Jest 框架超级测试

问题描述

我有点坚持使用 jest 和 super test 测试 lodash 库 lodash 库

A.routes.js

import express from 'express';
const router = express.Router();
const _ = require('lodash');
router.post('/',async (req,res,next) => {
    try {
      let data = req.body
      if(!_.isEqual(data,{"hello":"hello"}){
               console.log('Not Equal') // This line is not getting covered in Code Coverage
            }
     }.catch(e=>{
      console.log(e);
  })
});

export default router;

A.route.test.js

import a from 'A.route'
import express from 'express';
import supertest from 'supertest';
let _ = require('lodash');

_.isEqual = jest.fn();

describe('API Calls',() => {
    const app = express();
    let request;

    beforeAll(() => {
        request = supertest(app);
    });

    beforeEach(()=>{
        jest.resetModules(); 
    });

test('Successful call to post /',async () => {
        const body= {
            "Hello": "Not Hello"
        };
        
        _.isEqual.mockResolvedValueOnce(false);
        await request.post('/')
            .set('Content-Type','application/json')
            .set('Authorization','authToken')
            .send(body);
        
    });
});

代码覆盖率不能覆盖console.log('Not Equal');我试过_.isEqual.mockImplementation(()=>return false);也试过 _.isEqual.mockReturnValueOnce(false)

解决方法

您应该测试此 API 的行为。这意味着您应该关心响应而不是实现细节。您应该传入一个输入，例如 req.body，以断言结果是否符合您的预期。

由于你的代码无法执行，我随意添加一些代码来演示

例如

a.router.js：

import express from 'express';
const router = express.Router();
const _ = require('lodash');

router.use(express.json());
router.post('/',async (req,res,next) => {
  try {
    let data = req.body;
    console.log('data: ',data);
    if (!_.isEqual(data,{ hello: 'hello' })) {
      res.send('Not Equal');
    } else {
      throw new Error('Equal');
    }
  } catch (e) {
    res.send(`Error: ${e.message}`);
  }
});

export default router;

a.router.test.js：

import a from './a.router';
import express from 'express';
import supertest from 'supertest';

describe('API Calls',() => {
  const app = express();
  let request;

  beforeAll(() => {
    app.use(a);
    request = supertest(app);
  });

  test('Successful call to post /',async () => {
    const body = {
      Hello: 'Not Hello',};
    const res = await request
      .post('/')
      .set('Content-Type','application/json')
      .set('Authorization','authToken')
      .send(body);
    expect(res.text).toEqual('Not Equal');
  });

  test('should handle error',async () => {
    const body = {
      hello: 'hello','authToken')
      .send(body);
    expect(res.text).toEqual('Error: Equal');
  });
});

测试结果：

 PASS  examples/67536129/a.router.test.js (8.606 s)
  API Calls
    ✓ Successful call to post / (48 ms)
    ✓ should handle error (5 ms)

  console.log
    data:  { Hello: 'Not Hello' }

      at examples/67536129/a.router.js:9:13

  console.log
    data:  { hello: 'hello' }

      at examples/67536129/a.router.js:9:13

-------------|---------|----------|---------|---------|-------------------
File         | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
-------------|---------|----------|---------|---------|-------------------
All files    |     100 |      100 |     100 |     100 |                   
 a.router.js |     100 |      100 |     100 |     100 |                   
-------------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed,1 total
Tests:       2 passed,2 total
Snapshots:   0 total
Time:        9.424 s