qs.js
function parse(str) {
    let arr = str.split('&');
    let obj = {};
    arr.forEach((item) => {
        let [key, val] = item.split('=');
        obj[key] = val;
    });
    return obj;
}
function stringify(obj) {
    let arr = [];
    for (let key in obj) {
        arr.push(key + '=' + obj[key]);
    }
    return arr.join('&');
}
exports.parse = parse;
exports.stringify = stringify;
| 问题 | 解决方案 | 
|---|---|
| 污染 源代码里混杂了很多测试代码 | 从源代码中抽离出去 | 
| 零散 杂乱无章,不能分组和分类 | 整体规划 和设计 | 
| 没有持久化 没有存储 | 把测试文件单独存放 | 
| 手动跑测试比较麻烦 | 自动运行并显示结果 | 
Test-Driven-Development 测试驱动开发,
cnpm i jest --save-dev 
cnpm i jest -g 
**test.js
jest npm jest 
npm test
qs.test.js
let { parse, stringify } = require('./qs');
describe('parse', () => {//分组
    test('one', () => {//测试用例
        expect(parse("name=zfpx").name).toBe('zfpx');
    });
    test('two', () => {
        expect(parse("name=zfpx&age=9").age).toBe('9');
    });
});
describe('stringify', () => {
    test('one', () => {
        expect(stringify({ name: 'zfpx' })).toBe('name=zfpx');
    });
    test('two', () => {
        expect(stringify({ name: 'zfpx', age: 9 })).toBe('name=zfpx&age=9');
    });
});
module.exports = {
    testMatch: ['**/__tests__/**/*.js?(x)', '**/?(*.)(spec|test).js?(x)'],//设置识别哪些文件是测试文件(glob形式),与testRegex互斥,不能同时写
    testRegex: '(/__tests__).*|(\\.|/)(test|spec))\\.jsx?$',//设置识别哪些文件是测试文件(正则形式),与testMatch互斥,不能同时写
    testEnvironment: 'jsdom',//测试环境,默认值是:jsdom,可修改为node
    rootDir: '',//默认值:当前目录,一般是package.json所在的目录。
    moduleFileExtensions: ['js', 'json', 'jsx', 'node']//测试文件的类型
}
test('matchers', () => {
    const a = {
        name: 'a',
        home: {
            name: 'beijing'
        }
    }
    const b = {
        name: 'a',
        home: {
            name: 'beijing'
        }
    }
    expect(a).toEqual(b)
    expect([1, 2, 3]).toEqual([1, 2, 3])
    expect(null).toBeNull()
    expect([1, 2, 3]).toContain(1)
    expect(b).toHaveProperty('home')
    expect('abc').toContain('b')
    expect('abc').toMatch(/^\w+$/)
    expect('123').not.toContain('4')
})
function remove(node) {
    node.parentNode.removeChild(node);
}
function on(node, type, handler) {
    node.addEventListener(type, handler);
}
exports.remove = remove;
exports.on = on;
let { remove, on } = require('../src/dom');
describe('dom', () => {
    test('remove', () => {
        document.body.innerHTML = '<div id="container"><span id="hello">hello</span></div>';
        let container = document.getElementById('container');
        expect(container.nodeName.toLocaleLowerCase()).toBe('div');
        let hello = document.getElementById('hello');
        expect(hello.nodeName.toLocaleLowerCase()).toBe('span');
        remove(hello);
        let hello2 = document.getElementById('hello');
        expect(hello2).toBeNull();
    })
    test('on', () => {
        document.body.innerHTML = '<div id="container"><button id="clickMe">click</button></div>';
        let clickMe = document.getElementById('clickMe');
        on(clickMe, 'click', () => {
            clickMe.innerHTML = 'clicked';
        });
        clickMe.click();
        expect(clickMe.innerHTML).toBe('clicked');
    })
});
<div id="tab">
    <div>
        <a href="#" class="tab-button">选项1</a>
        <a href="#" class="tab-button">选项2</a>
    </div>
    <div>
        <div class="tab-panel">面板1</div>
        <div class="tab-panel">面板2</div>
    </div>
</div>
class Tab{
    constructor(id,buttonClass,panelClass){
        this.tab = tab = document.querySelector('#'+id);
        this.buttons = Array.from(tab.querySelectorAll('.'+buttonClass));
        this.panels = Array.from(tab.querySelectorAll('.'+panelClass));
        this.select(0);
        this.bindEvent();
    }
    select(index){
        this.buttons.forEach(button=>button.style.backgroundColor= 'white');
        this.buttons[index].style.backgroundColor= 'red';
        this.panels.forEach(panel=>panel.style.display= 'none');
        this.panels[index].style.display= 'block';
    }
    bindEvent(){
        for(let i=0;i<this.buttons.length;i++){
            this.buttons[i].addEventListener('click',()=>{
                this.select(i);
            });
        }
    }
}
module.exports = Tab;
const Tab = require('../src/tab');
const fs = require('fs');
const path = require('path');
test('tab',function(){
    document.body.innerHTML = fs.readFileSync(path.resolve(__dirname,'tab.html'),'utf8');
    const tab = new Tab('tab','tab-button','tab-panel');
    expect(tab.buttons[0].style.backgroundColor).toBe('red');
    expect(tab.buttons[1].style.backgroundColor).toBe('white');
    expect(tab.panels[0].style.display).toBe('block');
    expect(tab.panels[1].style.display).toBe('none');
    tab.buttons[1].click();
    expect(tab.buttons[0].style.backgroundColor).toBe('white');
    expect(tab.buttons[1].style.backgroundColor).toBe('red');
    expect(tab.panels[0].style.display).toBe('none');
    expect(tab.panels[1].style.display).toBe('block');
});
test('async',(done)=>{
    setTimeout(()=>{
        expect(2).toBe(2);
        done();
    },1000);
});
__tests__\users.js
jest.mock('../js/ajax');
const getUsers = require('../js/getUsers');
test('getUsers',(done)=>{
    document.body.innerHTML = `<ul id="users"></ul>`;
    getUsers('/users.json','users',()=>{
        const ul = document.querySelector('#users');
        const lis = ul.querySelectorAll('li');
        expect(lis.length).toBe(2);
        expect(lis[1].innerHTML).toBe('zfpx2');
        done();
    });
});
\js\getUsers.js
var ajax = require('./ajax');
function getUsers(url,id,callback){
 const users = document.getElementById(id);
 ajax(url,data=>{
     console.log('ajax ok');
     data = JSON.parse(data);
     users.innerHTML = data.map(item=>`<li>${item.name}</li>`).join('');
     callback&&callback();
 });
}
module.exports = getUsers;
\js\ajax.js
function ajax(url,success){
  const xhr = new XMLHttpRequest();
  xhr.onreadystatechange = ()=>{
      if(xhr.readyState == 4){
          success&success(xhr.responseText);
      }
  }
  xhr.open('get',url);
  xhr.send(null);
}
module.exports = ajax;
js__mocks__\ajax.js
const fs = require('fs');
const path = require('path');
const ajax = (url,success)=>{
   setTimeout(()=>{
       success(JSON.stringify([{name:'zfpx1'},{name:'zfpx2'}]));
   },1000);
}
module.exports = ajax;
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <ul id="users"></ul>
    <script>
        let module = {};
        let require = () => ajax;
    </script>
    <script src="/js/ajax.js"></script>
    <script src="/js/getUsers.js"></script>
    <script>
        getUsers('http://localhost:3000/users.json', 'users');
    </script>
</body>
</html>
users.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <ul id="users"></ul>
    <script>
        let module = {};
        let require = () => ajax;
    </script>
    <script src="/js/ajax.js"></script>
    <script src="/js/getUsers.js"></script>
    <script>
        getUsers('http://localhost:3000/users.json', 'users');
    </script>
</body>
</html>
server.js
const express = require('express');
const path = require('path');
const app = express();
app.use(express.static(__dirname));
app.get('/',function(req,res){
    res.sendFile(path.resolve(__dirname,'users.html'));
});
app.get('/users.json',function(req,res){
  res.json([{name:'zfpx1'},{name:'zfpx2'}]);
});
app.listen(3000);
npx jest --coverage
gulp内部使用了node-glob模块来实现其文件匹配功能。我们可以使用下面这些特殊的字符来匹配我们想要的文件:
| 匹配符 | 说明 | 
|---|---|
| 星 | 匹配文件路径中的0个或多个字符,但不会匹配路径分隔符 | 
| ** | 匹配路径中的0个或多个目录及其子目录 | 
| [...] | 匹配方括号中出现的字符中的任意一个,当方括号中第一个字符为^或!时,则表示不匹配方括号中出现的其他字符中的任意一个 | 
| !(pattern pattern pattern) | 匹配任何与括号中给定的任一模式都不匹配的 | 
| ?(pattern pattern pattern) | 匹配括号中给定的任一模式0次或1次,类似于js正则中的? | 
| +(pattern pattern pattern) | 匹配括号中给定的任一模式至少1次,类似于js正则中的+ | 
| (pattern pattern pattern) | 匹配括号中给定的任一模式0次或多次,类似于js正则中的 * | 
| @(pattern pattern pattern) | 匹配括号中给定的任一模式1次,类似于js正则中的 | 
| glob | 匹配 | |
|---|---|---|
| * | 能匹配 a.js,x.y,abc,abc/,但不能匹配a/b.js | |
| . | a.js,style.css,a.b,x.y | |
| //*.js | 能匹配 a/b/c.js,x/y/z.js,不能匹配a/b.js,a/b/c/d.js | |
| ** | 能匹配 abc,a/b.js,a/b/c.js,x/y/z,x/y/z/a.b,能用来匹配所有的目录和文件 | |
| a/**/z | 能匹配 a/z,a/b/z,a/b/c/z,a/d/g/h/j/k/z | |
| a/**b/z | 能匹配 a/b/z,a/sb/z,但不能匹配a/x/sb/z,因为只有单**单独出现才能匹配多级目录 | |
| ?.js | 能匹配 a.js,b.js,c.js | |
| a?? | 能匹配 a.b,abc,但不能匹配ab/,因为它不会匹配路径分隔符 | |
| [xyz].js | 只能匹配 x.js,y.js,z.js,不会匹配xy.js,xyz.js等,整个中括号只代表一个字符 | |
| [^xyz].js | 能匹配 a.js,b.js,c.js等,不能匹配x.js,y.js,z.js |