- 结合一个 Todo-List 的例子进行 React 单元测试
- 模板使用:React、Redux、Webpack@4、Babel@7
项目地址
https://github.com/ringcrl/react-todolist-enzyme
环境搭建
复习一下 React 环境搭建。
相关文档
依赖安装
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# react
yarn add react react-dom react-redux redux
# babel
yarn add -D @babel/cli @babel/core @babel/polyfill @babel/preset-env @babel/preset-react babel-jest babel-loader
# webpack
yarn add -D webpack webpack-cli webpack-dev-server
# scss
yarn add -D node-sass sass-loader style-loader css-loader
# 测试套件
yarn add -D jest enzyme enzyme-adapter-react-16
环境配置
babel.config.js
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const presets = [
[
'@babel/env',
{
targets: {
edge: '17',
firefox: '60',
chrome: '67',
safari: '11.1'
}
}
],
['@babel/preset-react']
];
module.exports = { presets };
jest.config.js
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module.exports = {
verbose: true,
modulePaths: ['<rootDir>/__test__/'],
moduleNameMapper: {
'.(css|less)$': '<rootDir>/__test__/NullModule.js'
},
setupFilesAfterEnv: ['<rootDir>/__test__/setupTests.js'],
transform: {
'^.+\\.jsx?$': 'babel-jest'
}
};
webpack.config.js
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const webpack = require('webpack');
const env = process.env.NODE_ENV;
const path = require('path');
module.exports = {
mode: 'development',
devtool: 'eval',
entry: ['./src/index.jsx'],
output: {
path: path.resolve(__dirname, 'dist'),
filename: 'bundle.js',
publicPath: '/dist'
},
module: {
rules: [
{
test: /\.js|jsx$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader'
}
},
{
test: /\.scss$/,
use: [
{
loader: 'style-loader' // 将 JS 字符串生成为 style 节点
},
{
loader: 'css-loader' // 将 CSS 转化成 CommonJS 模块
},
{
loader: 'sass-loader' // 将 Sass 编译成 CSS
}
]
}
]
},
resolve: {
extensions: ['.jsx', '.js']
},
plugins: [
new webpack.DefinePlugin({
'process.env.NODE_ENV': JSON.stringify(env)
})
]
};
.eslintrc.js
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module.exports = {
"parser": "babel-eslint",
"parserOptions": {
"ecmaVersion": 6,
"sourceType": "module",
"ecmaFeatures": {
"jsx": true,
"modules": true,
"experimentalObjectRestSpread": true
}
},
"env": {
"browser": true,
"commonjs": true,
"es6": true,
"node": true,
"jest": true,
},
"globals": {
"Raven": true, // 文件中注释 /* global Raven */
},
"extends": [
"eslint:recommended", // https://cn.eslint.org/docs/rules/
"plugin:react/recommended" // https://github.com/yannickcr/eslint-plugin-react
],
"parserOptions": {
"ecmaVersion": 2018,
"sourceType": "module"
},
"rules": {
"prefer-const": ["error"],
"no-var": ["error"],
"linebreak-style": ["error", "unix"],
"quotes": ["error", "single"],
"semi": ["error", "always"],
"no-control-regex": ["off"],
"no-useless-escape": ["off"],
"no-console": ["off"],
"react/prop-types": ["off"],
}
};
.editorconfig
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[*]
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = false
insert_final_newline = true
indent_style = space
indent_size = 2
[{*.yml,*.json}]
indent_style = space
indent_size = 2
Todo list
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src
├── actions
│ └── index.js
├── components
│ ├── todo-creator
│ │ └── index.jsx
│ └── todo-item
│ └── index.jsx
├── constants
│ └── index.js
├── container
│ ├── index.jsx
│ └── index.scss
├── index.jsx
└── reducers
├── index.js
└── todos.js
一个普通的 React、Redux 应用,效果如下
- 回车后添加 Todo Item
- 点击 Todo Item 前面的 Input 删除此 Item
__test__
文件概述
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__test__
├── NullModule.js
├── components
│ ├── todo-creator
│ │ └── index.test.js
│ └── todo-item
│ └── index.test.js
├── reducers
│ └── todos.test.js
└── setupTests.js
NullModule.js
导出的是空对象,用于跳过样式文件的检测,与jest.config.js
里面的moduleNameMapper
字段对应setupTests.js
用于使用 Jest 配置 Enzyme 和适配器,文档
测试内容
- TodoCreator(输入框)
- 正确渲染了 render input 输入框
- 如果输入框有输入内容,回车后 addTodo reducer 被调用
- 如果输入框没有输入内容,回车后 addTodo reducer 不被调用
- addTodo 之后清空输入框
- TodoItem
- Todo item 被正确渲染
- input 改变时删除 item
- 渲染 item 的 title
- reducers
- 初始 state 正确
- ADD_TODO 结果正确
- DELETE_TODO 结果正确
具体逻辑看 __tests__
部分代码,主要使用了 enzyme 的类 JQ API,进行 “DOM” 检测、事件触发等操作。
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expect(wrapper.find('input').length).toBe(1)
wrapper.find('input').simulate('change');
expect(wrapper.find('.todo-title').text()).toBe(props.todo.text);
const mockEventObj = {
key: 'Enter',
target: {
value: 'TEST'
}
};
wrapper.find('input').simulate('keydown', mockEventObj);
expect(props.addTodo).toBeCalled();
// ...