在之前的文章中了解了webpack v4的特性，現(xiàn)在將知識用于實(shí)踐间校，對之前寫的一個react腳手架進(jìn)行打包性能的優(yōu)化。
優(yōu)化類目
- 樣式分離
- 第三方資源分離
- 區(qū)分開發(fā)環(huán)境
- 熱更新
- 提取公共代碼
1. CSS分離
npm install extract-text-webpack-plugin -D
webpack.config.js
將css页慷、less憔足、sass文件單獨(dú)從打包文件中分離
+ let cssExtract = new ExtractTextWebpackPlugin({
+ filename: 'css.css',
+ allChunks: true
+ });
+ let sassExtract = new ExtractTextWebpackPlugin('sass.css')
+ let lessExtract = new ExtractTextWebpackPlugin('less.css')
在webpack.config.js中單獨(dú)添加規(guī)則，
- test：匹配處理文件的擴(kuò)展名的正則表達(dá)式
- include/exclude手動指定必須處理的文件夾或屏蔽不需要處理的文件夾
{
test: /\.css$/,
use: cssExtract.extract({
fallback: "style-loader",
use: ['css-loader?minimize','postcss-loader'],
publicPath: "/dist"
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.scss$/,
use: sassExtract.extract({
fallback: "style-loader",
use: ["css-loader?minimize","sass-loader"],
publicPath: "/dist"
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.less$/,
loader: lessExtract.extract({
use: ["css-loader?minimize", "less-loader"]
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
然后運(yùn)行webpack命令時(shí)報(bào)錯
compilation.mainTemplate.applyPluginsWaterfall is not a function
Use Chunks.groupsIterable and filter by instanceof Entrypoint instead
研究得出結(jié)論：webpack升級到v4然而響應(yīng)的插件沒有升級的原故酒繁。
解決方法：安裝指定版本的依賴
"html-webpack-plugin": "^3.0.4"
"extract-text-webpack-plugin": "^4.0.0-beta.0"
resolve
指定extension之后可以不用在require或是import的時(shí)候加文件擴(kuò)展名,會依次嘗試添加擴(kuò)展名進(jìn)行匹配
resolve: {
//引入模塊的時(shí)候滓彰，可以不用擴(kuò)展名
extensions: [".js", ".less", ".json"],
alias: {//別名
"bootstrap": "bootstrap/dist/css/bootstrap.css"
}
}
監(jiān)聽文件修改
webpack模式下使用，webpack-dev-server模式不用州袒，可以將watch改為false
watchOptions: {
ignored: /node_modules/,
aggregateTimeout: 300, //監(jiān)聽到變化發(fā)生后等300ms再去執(zhí)行動作揭绑，防止文件更新太快導(dǎo)致編譯頻率太高
poll: 1000 //通過不停的詢問文件是否改變來判斷文件是否發(fā)生變化，默認(rèn)每秒詢問1000次
}
提取公共代碼
optimization: {
splitChunks: {
cacheGroups: {
commons: {
chunks: "initial",
minChunks: 2,
maxInitialRequests: 5, // The default limit is too small to showcase the effect
minSize: 0 // This is example is too small to create commons chunks
},
vendor: {
test: /node_modules/,
chunks: "initial",
name: "vendor",
priority: 10,
enforce: true
}
}
}
}
分離react react-dom ant公共代碼
- 方法一：externals
在頁面上引入第三方資源庫郎哭，然后使用externals防止將某些 import 的包(package)打包到 bundle 中他匪，而是在運(yùn)行時(shí)(runtime)再去從外部獲取這些擴(kuò)展依賴(external dependencies)。
<script src="https://cdn.bootcss.com/react/16.4.0-alpha.0911da3/cjs/react.production.min.js"></script>
<script src="https://cdn.bootcss.com/react-dom/16.4.0-alpha.0911da3/cjs/react-dom-server.browser.production.min.js"></script>
externals: { 'react': 'React', 'react-dom': 'ReactDOM', // 提出ant design的公共資源, }
- 方法二：DLL
DLL在上篇文章中寫過夸研，但是打包后一直出現(xiàn)
image
后來才發(fā)現(xiàn)是頁面上沒有引入資源邦蜜。。亥至。悼沈。（我一直以為會webpack自動生成在頁面上....）
在index.html文件中引入
<script src="./vendor/react.dll.js"></script>
分離成功！上代碼
webpack.base.js
var path = require('path');
var webpack = require('webpack');
var ExtractTextWebpackPlugin = require("extract-text-webpack-plugin");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CleanWebpackPlugin = require('clean-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin')
let cssExtract = new ExtractTextWebpackPlugin({
filename: 'css.css',
allChunks: true
});
let sassExtract = new ExtractTextWebpackPlugin('sass.css')
let lessExtract = new ExtractTextWebpackPlugin('less.css')
module.exports = {
entry:'./src/index.js',
output: {
path: path.resolve(__dirname, './dist'),
filename: 'bundle.[hash:8].js',
publicPath: ''
},
resolve: {
//引入模塊的時(shí)候抬闯，可以不用擴(kuò)展名
extensions: [".js", ".less", ".json"],
alias: {//別名
"bootstrap": "bootstrap/dist/css/bootstrap.css"
},
modules: [path.resolve(__dirname, 'node_modules')]
},
/* externals: {
'react': 'React',
'react-dom': 'ReactDOM',
// 提出ant design的公共資源
//'antd': 'antd',
},*/
devtool: 'source-map',
devServer: {
contentBase:path.resolve(__dirname,'dist'),
publicPath: '/',
port: 8080,
hot:true,
compress:true,
historyApiFallback: true,
inline: true
},
watch: false, //只有在開啟監(jiān)聽模式時(shí)井辆，watchOptions才有意義
watchOptions: {
ignored: /node_modules/,
aggregateTimeout: 300, //監(jiān)聽到變化發(fā)生后等300ms再去執(zhí)行動作关筒，防止文件更新太快導(dǎo)致編譯頻率太高
poll: 1000 //通過不停的詢問文件是否改變來判斷文件是否發(fā)生變化溶握，默認(rèn)每秒詢問1000次
},
optimization: {
splitChunks: {
cacheGroups: {
commons: {
chunks: "initial",
minChunks: 2,
maxInitialRequests: 5, // The default limit is too small to showcase the effect
minSize: 0 // This is example is too small to create commons chunks
},
vendor: {
test: /node_modules/,
chunks: "initial",
name: "vendor",
priority: 10,
enforce: true
}
}
}
},
module: {
rules:[
{
test: /\.js$/,
use: {
loader:'babel-loader',
options: {
presets: ['env','es2015', 'react'],
}
},
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.css$/,
use: cssExtract.extract({
fallback: "style-loader",
use: ['css-loader?minimize','postcss-loader'],
publicPath: "/dist"
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.scss$/,
use: sassExtract.extract({
fallback: "style-loader",
use: ["css-loader?minimize","sass-loader"],
publicPath: "/dist"
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.less$/,
loader: lessExtract.extract({
use: ["css-loader?minimize", "less-loader"]
}),
include:path.join(__dirname,'./src'),
exclude:/node_modules/
},
{
test: /\.(html|htm)/,
use: 'html-withimg-loader'
},
{
test: /\.(png|jpg|gif|svg|bmp|eot|woff|woff2|ttf)/,
use: {
loader:'url-loader',
options:{
limit: 5 * 1024,
//指定拷貝文件的輸出目錄
outputPath: 'images/'
}
}
}
]
},
plugins: [
//定義環(huán)境變量
new webpack.DefinePlugin({
__development__: JSON.stringify(process.env.NODE_ENV)
}),
new CleanWebpackPlugin(['dist']),
cssExtract,
lessExtract,
sassExtract,
new HtmlWebpackPlugin({
title: 'React Biolerplate by YuanYuan',
template: './src/index.html',
filename: `index.html`,
hash: true
}),
new webpack.DllReferencePlugin({
manifest: path.join(__dirname, 'vendor', 'react.manifest.json')
}),
new CopyWebpackPlugin([{
from: path.join(__dirname,'vendor'),//靜態(tài)資源目錄源地址
to:'./vendor' //目標(biāo)地址，相對于output的path目錄
}]),
/* new webpack.optimize.CommonsChunkPlugin({
name: 'common' // 指定公共 bundle 的名稱蒸播。
+ })*/
new webpack.HotModuleReplacementPlugin(), // 熱替換插件
new webpack.NamedModulesPlugin() // 執(zhí)行熱替換時(shí)打印模塊名字
]
};
webpack.config.js
const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');//用來合并配置文件
const base = require('./webpack.base');
let other = '';
//console.log(process.env.NODE_ENV )
if (process.env.NODE_ENV == 'development') {
other = require('./webpack.dev.config');
} else {
other = require('./webpack.prod.config');
}
//console.log(merge(base, other));
module.exports = merge(base, other);
webpack.prod.config.js
const path = require('path');
const webpack = require('webpack');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin')
module.exports = {
output: {
filename: 'bundle.min.js',
},
plugins: [
new UglifyJSPlugin({sourceMap: true})
]
}
image
優(yōu)化后手架地址
image
打包速度優(yōu)化睡榆，打包文件細(xì)化萍肆，改造成功~
