javascript - 如何在JavaScript中用Jest npm模拟soket.io(how to mock soket.io with jest npm in javascript)

Question

I am working on a project chat app in java script using socket.io back end only, And I want to write unit test using jest ,npm .

(我正在仅使用socket.io后端以Java脚本开发项目聊天应用程序，并且我想使用jest，npm编写单元测试。)

And I got trouble on 1. how to mock socket.io with jest 2. how to test console.log results

(我遇到了麻烦1.如何用玩笑模拟socket.io 2.如何测试console.log结果)

console.log = jest.fn();


test ('check chat status', () => {
  expect(console.log.mock.calls.length).toBe(0);
  socket.on('connect');
  expect(console.log.mock.calls.length).toBe(1);
  expect(console.log.mock.calls[0][0]).toBe('Chat started
');
});

afterEach(() => {
  jest.clearAllMocks();
});

the code I want to test is the following , app.js and chat.js

(我要测试的代码如下，app.js和chat.js)

'use strict';

const io = require('socket.io')(3000);

io.on('connection', (socket) => {
  socket.on('username', (data) => {
    socket.username = data.username;
    console.log(`${socket.username} joined the chat!`);

    socket.broadcast.emit('new user', socket.username);
  });

  socket.on('message', (data) => {
    socket.broadcast.emit('message', {user: socket.username, message: data});
  });

  socket.on('disconnect', () => {
    console.log(`User left the chat`);
  });
});


chat.js 
'use strict';

const io = require('socket.io-client');
const socket = io.connect('http://localhost:3000');

const readline = require('readline');
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

let username;

socket.on('connect', () => {
  console.log(`Chat started
`);

  rl.question('What is your name? ', (answer) => {
    username = answer;
    socket.emit('username', {username: username});
  });
});

rl.on('line', (message) => {
  socket.emit('message', message);
});

socket.on('message', (data) => {
  console.log(`${data.user}: ${data.message}`);
});

socket.on('new user', (data) => {
  console.log(`${data} joined the chat
`);
});

But more features will be added like authontication, attchement, private chat ...

this file is sent to be checked

(该文件已发送以供检查)

  ask by Meron Alemu translate from so

Answer 1

等待大神答复