import Vue from 'vue'
import Router from 'vue-router'

// webpackChunkName 打包后的文件名
const Menu = () => import(/* webpackChunkName: 'Menu' */ '@/pages/menu/index.vue')

export default new Router({
 routes: [
 {
  path: '/',
  name: 'Menu',
  component: Menu
 }
 ]
})

{
 ... 
 "comments": true, // 输出编译信息
 "plugins": ["transform-vue-jsx", "transform-runtime"]
}

output: {
 path: config.build.assetsRoot,
 filename: utils.assetsPath('js/[name].[chunkhash].js'),
 chunkFilename: utils.assetsPath('js/[name].js') // 使用webpackChunkName定义的文件名
},

new UglifyJsPlugin({
  parallel: true, // 并行
  cache: true // 缓存
}),

productionSourceMap:false

yarn add clean-webpack-plugin add-asset-html-webpack-plugin@2.1.0 --dev

const webpack = require('webpack')
const path = require('path')
const CleanWebpackPlugin = require('clean-webpack-plugin')
const dllPath = path.resolve(__dirname, '../src/assets/dll') // dll文件存放的目录

process.env.NODE_ENV = 'production' // NODE_ENV 设置为 production 减少依赖

module.exports = {
 entry: { // 把 vue 相关模块的放到一个单独的动态链接库
 vue: ['babel-polyfill', 'vue', 'vue-router', 'vuex', 'axios', 'element-ui']
 },
 output: {
 filename: '[name]-[hash].dll.js', // 生成vue.dll.js
 path: dllPath,
 library: '_dll_[name]'
 },
 plugins: [ 
 new CleanWebpackPlugin(['*.js'], { // 清除之前的dll文件
  root: dllPath
 }), 
 new webpack.DefinePlugin({  
  'process.env': {
  NODE_ENV: JSON.stringify(process.env.NODE_ENV) // 设置环境变量
  }
 }), 
 new webpack.DllPlugin({
  name: '_dll_[name]',  // manifest.json 描述动态链接库包含了哪些内容
  path: path.join(__dirname, './', '[name].dll.manifest.json')
 }), 
 // 压缩代码
 new webpack.optimize.UglifyJsPlugin({
  compress: {
  warnings: false,
  pure_funcs: ['console.log']
  },
  sourceMap: false
 })
 ]
}

"scripts": { 
 "dll": "webpack --config build/webpack.dll.conf.js" // dll打包命令
 },

const AddAssetHtmlPlugin = require('add-asset-html-webpack-plugin')

plugins: [ 
 // 引用 manifest.json
 new webpack.DllReferencePlugin({
  manifest: require('./vue.dll.manifest.json')
 }), 
 // 将 dll 注入到 生成的 html 模板中
 new AddAssetHtmlPlugin({
  filepath: path.resolve(__dirname, '../src/assets/dll/*.js'), // dll文件位置
  publicPath: config.build.assetsPublicPath + utils.assetsPath('dll/'), // dll 引用路径
  outputPath: config.build.assetsPublicPath + utils.assetsPath('dll/'), // dll最终输出的目录
  includeSourcemap: false
  // hash: true,
 }),
 ...
]

yarn run dll // 运行一次生成 dll 文件即可，下次构建时不必运行
yarn run build