基于 Ant Desigin 的后台管理项目打包优化实践

背景

按照 Ant Design 官网用 React 脚手构建的后台项目，刚接手项目的时候大概30条路由左右，个人用的机子是 Mac 8G 内存，打包完成须要耗时2分钟左右，决定优化一下。css

项目技术栈： React + React Router + TypeScript + Ant Design html

构建时间慢可能的缘由：node

React 脚手架默认打包构建出来的文件包含 map 文件react
Ant Desigin 以及项目中使用的第三方模块太大webpack
babel-loader 编译过程慢git

React 脚手架修改 Webpack 配置方案：github

npm run rject 暴露出 Webpack 配置信息，直接进行修改。web
使用 react-app-rewired （一个对 create-react-app 进行自定义配置的社区解决方案）Ant Design 官网推荐。typescript

自定义Webpack配置步骤：shell

基础配置
开发环境配置
生产环境配置

使用 customize-cra 修改React 脚手架配置实践

一、准备工做

npm i react-app-rewired customize-cra --save-dev 安装 react-app-rewired ,customize-cra，它提供一些修改 React 脚手架默认配置函数,具体参见：https://github.com/arackaf/customize-cra

安装后，修改 package.json 文件的 scripts

"scripts": { "start": "react-app-rewired start", "build": "react-app-rewired build", "test": "react-app-rewired test", }

项目根目录建立一个 config-overrides.js 用于修改Webpack 配置。

Ant Desigin 提供了一个按需加载的 babel 插件 babel-plugin-import

antd-dayjs-webpack-plugin是Ant Desigin 官方推荐的插件，用于替换moment.js

安装 npm i babel-plugin-import --save-dev,并修改config-overrides.js 配置文件

override函数用来覆盖React脚手架Webpack配置；fixBabelImports修改babel配置

const { override, fixBabelImports，addWebpackPlugin } = require('customize-cra'); const AntdDayjsWebpackPlugin = require('antd-dayjs-webpack-plugin'); module.exports = override( fixBabelImports('import', { libraryName: 'antd', libraryDirectory: 'es', style: 'css', }), addWebpackPlugin(new AntdDayjsWebpackPlugin()) );

以上是Ant Desigin推荐的作法。

二、首屏加载优化

npm i react-loadable customize-cra --save安装react-loadable模块,而后在路由文件里使用以下，loading组件能够自定义。这样打包的时候会为每一个路由生成一个chunk，以此来实现组件的动态加载。

须要安装"@babel/plugin-syntax-dynamic-import这个插件，编译import()这种语法

import Loadable from 'react-loadable'; const Index = Loadable({ loader:() => import('../components/Index'), loading:SpinLoading });

三、去掉 map 文件

首先安装依赖包webpack-stats-plugin webpack-bundle-analyzer 前者为了统计打包时间会在打包后的文件夹里生成一个stats.json文件，后者用来分析打包后的各个模块的大小。

process.env.GENERATE_SOURCEMAP = "false";用来去掉打包后的map文件

const { override, fixBabelImports } = require('customize-cra'); const { StatsWriterPlugin } = require("webpack-stats-plugin"); const AntdDayjsWebpackPlugin = require('antd-dayjs-webpack-plugin'); const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin let startTime = Date.now() if(process.env.NODE_ENV === 'production') process.env.GENERATE_SOURCEMAP = "false"

// 自定义生产环境配置
const productionConfig = (config) =>{ if(config.mode === 'production'){ config.plugins.push(...[ new StatsWriterPlugin({ fields: null, transform: (data) => { let endTime = Date.now() data = { Time: (endTime - startTime)/1000 + 's'
 } return JSON.stringify(data, null, 2); } }), new BundleAnalyzerPlugin() ]) } return config } module.exports = override( productionConfig, fixBabelImports('import', { libraryName: 'antd', libraryDirectory: 'es', style: 'css', }), addWebpackPlugin(new AntdDayjsWebpackPlugin()) );

去掉map文件的打包时间，大约60s左右。查看打包后生成的分析图发现Ant Desigin的一些组件被重复打包，打包出来一共有13M多。

四、更细化分包

在productionConfig配置添加，在入口文件添加vendors用来分离稳定不变的模块；common用来抽离复用模块；styles将css文件抽离成一个文件；

// 针对生产环境修改配置
const productionConfig = (config) =>{ if(config.mode === 'production'){ const splitChunksConfig = config.optimization.splitChunks; if (config.entry && config.entry instanceof Array) { config.entry = { main: config.entry, vendors: ["react", "react-dom", "react-router-dom", "react-router"] } } else if (config.entry && typeof config.entry === 'object') { config.entry.vendors = ["react", "react-loadable","react-dom", "react-router-dom","react-router"]; } Object.assign(splitChunksConfig, { cacheGroups: { vendors: { test: "vendors", name: 'vendors', priority:10, }, common: { name: 'common', minChunks: 2, minSize: 30000, chunks: 'all' }, styles: { name: 'styles', test: /\.css$/, chunks: 'all', priority: 9, enforce: true } } }) config.plugins.push(...[ new StatsWriterPlugin({ fields: null, transform: (data) => { let endTime = Date.now() data = { Time: (endTime - startTime)/1000 + 's'
 } return JSON.stringify(data, null, 2); } }), new BundleAnalyzerPlugin() ]) } return config }

以上实际打包运行大约35S左右，实际打包后的模块一共2.41M，打包后生成的分析图发现Ant Design有个图标库特别大，大约有520kb，可是实际项目中用到的图标特别少。到此不想继续折腾React脚手架了，还不如从新配置一套Webpack替换脚手架。

五、总结

React脚手架配置太重，对于庞大的后台系统不实用
Ant Design的图标库没有按需加载的功能
修改React脚手架配置太麻烦

自定义Webpack配置实践

一、结果：替换掉脚手架后，陆陆续续新增路由到100条左右，打包耗时大概20s-30S之间，业务代码打包后1.49M，能够接受。

二、优化点：

利用autodll-webpack-plugin插件，生产环境经过预编译的手段将Ant React 等稳定的模块所有先抽离出来，只打包编译业务代码。
babel-loader 开启缓存
利用happypack加快编译速度
生产环境不开启devtool
细化分包
针对项目轻量级配置（后台项目，基本只在 Chrome 浏览器下使用）

问题：

抽离出来的第三方模块大概有3M多，通过zip大概也有800多Kb,首屏加载比较慢。若是结合externals属性将这些静态资源放置到CDN上或许加载会更快。

三、基础配置：

放于webpack.base.config.js文件

一、安装babel模块，使用的是babel7.0版本。

npm i install babel-loader @babel/core @babel/preset-env @babel/preset-react @babel/preset-typescript @babel/plugin-transform-runtime --save-dev
npm i @babel/runtime-corejs3 --save

在更目录下建立babel.config.js babel的配置文件

module.exports = function (api) { api.cache(true); const presets = ["@babel/env","@babel/preset-react","@babel/preset-typescript"]; const plugins = [ ["@babel/plugin-transform-runtime", { corejs: 3, }], "@babel/plugin-syntax-dynamic-import", "@babel/plugin-proposal-class-properties", ]; if (process.env.NODE_ENVN !== "production") { plugins.push(["import", { "libraryName": "antd", // 引入库名称
            "libraryDirectory": "es", // 来源,default: lib
            "style": "css" // 所有,or 按需'css'
 }]); } return { presets, plugins }; }

二、babel-loader配置：

const os = require('os'); const HappyPack = require('happypack'); const happyThreadPool = HappyPack.ThreadPool({ size: os.cpus().length }); module.exports = { ..... module: { rules: [ { test: /\.(ts|tsx|js|jsx)$/, exclude: /node_modules/, loaders: ['happypack/loader?id=babel'] } }, plugins: [ new HappyPack({ id: 'babel', threadPool: happyThreadPool, loaders: [{ loader:'babel-loader', options: { cacheDirectory: true } }] }) ] }

三、mini-css-extract-plugin 插件打包抽离CSS到单独的文件

var MiniCssExtractPlugin = require('mini-css-extract-plugin'); var NODE_ENV = process.env.NODE_ENV var devMode = NODE_ENV !== 'production'; var utils = require('./utils') module.exports = { .... module: { rules: [ { test: /\.css$/, use: [ { loader: devMode ? 'style-loader' : MiniCssExtractPlugin.loader, options: { // only enable hot in development
 hmr: devMode, // if hmr does not work, this is a forceful method.
              reloadAll: true, }, }, "css-loader" ], }, ] }, plugins: [ new MiniCssExtractPlugin({ //utils.assetsPath 打包后存放的地址
      filename: devMode ? '[name].css' : utils.assetsPath('css/[name].[chunkhash].css'), chunkFilename: devMode ? '[name].css' : utils.assetsPath('css/[name].[chunkhash].css'), ignoreOrder: false, // Enable to remove warnings about conflicting order
 }) ] }

四、html-webpack-plugin 生成html 文件

const HtmlWebpackPlugin = require('html-webpack-plugin') var htmlTplPath = path.join(__dirname, '../public/') module.exports = { .... plugins: [ new HtmlWebpackPlugin({ filename: 'index.html', template: htmlTplPath + 'index.html', inject: true, }) ] }

五、webpack.DefinePlugin生成业务代码能够获取的变量，能够区分环境

const webpack = require('webpack') module.exports = { .... plugins: [ new webpack.DefinePlugin({ 'process.env.NODE_ENV': JSON.stringify(devMode ? 'development' : 'production'), 'perfixerURL': JSON.stringify('//yzadmin.111.com.cn') }), }

四、开发环境配置：

放于webpack.development.config.js文件

var path = require('path'); var webpack = require('webpack'); var merge = require('webpack-merge'); var FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin') var entryScriptPath = path.join(__dirname, '../src/') var base = require('./webpack.base.config'); module.exports = merge(base, { entry: { app: [entryScriptPath+'index'] // Your appʼs entry point
 }, output: { path: path.join(__dirname, '../dist/'), filename: '[name].js', chunkFilename: '[name].[chunkhash].js' }, module: { }, plugins: [ new webpack.ContextReplacementPlugin(/moment[\/\\]locale$/, /zh-cn/), new webpack.HotModuleReplacementPlugin(), new FriendlyErrorsPlugin(), ] });

start.js文件,用于npm start启动本地服务

var webpack = require('webpack'); var opn = require('opn') var WebpackDevServer = require('webpack-dev-server'); var config = require('./webpack.development.config'); config.entry.app.unshift("webpack-dev-server/client?http://127.0.0.1:9000/", "webpack/hot/dev-server"); new WebpackDevServer(webpack(config), { publicPath: config.output.publicPath, hot: true, historyApiFallback: { index: '/public' } }).listen(9000, '127.0.0.1', function (err, result) { if (err) { return console.log(err); } opn('http://127.0.0.1:9000/') });

五、生产环境配置：

放于webpack.production.config.js文件

const path = require('path') const merge = require('webpack-merge') const baseWebpackConfig = require('./webpack.base.config'); const config = require('./webpack.env.config') const utils = require('./utils') const AutoDllPlugin = require('autodll-webpack-plugin'); const TerserJSPlugin = require('terser-webpack-plugin'); const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin'); function resolve(dir) { return path.join(__dirname, '..', dir) } const webpackConfig = merge(baseWebpackConfig, { module: { }, devtool: config.build.productionSourceMap ? '#source-map' : false, entry: { app: resolve('src/index'), }, output: { path: config.build.assetsRoot, filename: utils.assetsPath('js/[name].[chunkhash].js'), chunkFilename: utils.assetsPath('js/[name].[chunkhash].js') }, optimization: { minimizer: [new TerserJSPlugin({}), new OptimizeCSSAssetsPlugin({})], splitChunks: { cacheGroups: { common: { test: /[\\/]src[\\/]/, name: 'common', chunks: 'all', priority: 2, minChunks: 2, }, // 分离css到一个css文件
 styles: { name: 'styles', test: /\.css$/, chunks: 'all', priority: 9, enforce: true, } } }, runtimeChunk: { name:"manifest" } }, plugins: [ new AutoDllPlugin({ inject: true, // will inject the DLL bundles to index.html
      filename: '[name].dll.js', path: './dll', entry: { // 第三方库
        react: ["react","react-dom","react-router", "react-router-dom",'react-loadable'], antd: ['antd/es'], untils: ['qs','qrcode'], plugins:['braft-editor','js-export-excel'] } }) ] }) if (config.build.productionGzip) { const CompressionWebpackPlugin = require('compression-webpack-plugin') webpackConfig.plugins.push( new CompressionWebpackPlugin({ filename: '[path].gz[query]', algorithm: 'gzip', test: new RegExp( '\\.(' + config.build.productionGzipExtensions.join('|') +
        ')$' ), threshold: 10240, minRatio: 0.8 }) ) } if (config.build.bundleAnalyzerReport) { const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin webpackConfig.plugins.push(new BundleAnalyzerPlugin()) } module.exports = webpackConfig

build.js 用于npm run build构建

process.env.NODE_ENV = 'production'

var ora = require('ora') var path = require('path') var chalk = require('chalk') var shell = require('shelljs') var webpack = require('webpack') var config = require('./webpack.env.config') var webpackConfig = require('./webpack.production.config') var spinner = ora('building for production...') spinner.start() var assetsPath = path.join(config.build.assetsRoot, config.build.assetsSubDirectory) shell.config.silent = true shell.rm('-rf', assetsPath) shell.mkdir('-p', assetsPath) shell.cp('-R', 'static/*', assetsPath) shell.config.silent = false webpack(webpackConfig, function (err, stats) { spinner.stop() if (err) throw err process.stdout.write(stats.toString({ colors: true, modules: false, children: false, chunks: false, chunkModules: false }) + '\n\n') console.log(chalk.cyan('  Build complete.\n')) console.log(chalk.yellow( '  Tip: built files are meant to be served over an HTTP server.\n' +
    '  Opening index.html over file:// won\'t work.\n' )) })

修改package.json

"scripts": { "start": "node webpack/start.js", "build": "node webpack/build.js" },

六、总结

经过本次实践大体对Webpack有了初步了解，但关于Webpack的内部原理没有仔细探究过
对一些脚手架作配置修改的前提是须要了解Webpack基础内容
优化一个项目首先须要知道是大体什么缘由形成的，能够利用的工具备speed-measure-webpack-plugin,webpack-bundle-analyzer等
项目虽然加入了typeScript但并无很好的利用typeScript

最后

Webpack配置demo地址：https://github.com/ccokl/webpack/tree/master/_webpack_for_ant