据说webpack3 比webpack4 编译速度将近快了60%-80%，
成功升级之后，于是来记录下，项目主要是vue ^2.5.9 ， webpack ^4.10.2 ， webpack-dev-sever ^3.1.4 ，配合升级的还有vue-loader ^15
项目重现编译之后由原来的1.7MB 减少到1.1MB ，看来在压缩这块也是由效果的。
需要修改的地方有以下几点：
vue-loader 14 到15 需要增加如下配置
const VueLoaderPlugin = require('vue-loader/lib/plugin') ?++++const MiniCssExtractPlugin = require('mini-css-extract-plugin') ??// webpack 4 ?+++const ExtractTextPlugin = require('extract-text-webpack-plugin') //for webpack3 ?-----module.exports = {...plugins: [ ???????+ new VueLoaderPlugin(), ?++++ ???????+ new MiniCssExtractPlugin({filename:'mian.css'}) ?//for webpack 4 +++ ?????????- new ExtractTextPlugin({filename:'main.css'}) //for webpack 3 ---]...}webpack-dev-server 升级之后需做如下改动
devServer: { ????++ contentBase: path.resolve(__dirname, '../dos-html'), ?// 需要指定路径 ++ ???????port: 7001, ????????hot: true, ???????// open: false, ???????inline: true, ???????compress: true, ???????historyApiFallback: true, ??????.... ???},webpack 3 升级 4 之后需要改动的配置
plugins: [ ??//已经移除 ??new webpack.optimize.CommonsChunkPlugin({ ??????name: 'vendor', ??????minChunks: function (module) { ????????// any required modules inside node_modules are extracted to vendor ????????return ( ??????????module.resource && /\.js$/.test(module.resource) && ??????????module.resource.indexOf( path.join(__dirname, '../node_modules')) === 0 ????????) ??????} ????}), ???new webpack.optimize.UglifyJsPlugin(...）//已经移除}===> 修改为以下const UglifyJsPlugin = require('uglifyjs-webpack-plugin');moudel.exports = {mode: 'production', ++ 这里指定模式。...optimization: { ???splitChunks: { ?????name(module) { ???????return ( ?????????module.resource && /\.js$/.test(module.resource) && ?????????module.resource.indexOf(path.join(__dirname, '../node_modules')) === 0 ???????) ?????} ???}, ???minimize: true, ????minimizer: [ ?????new UglifyJsPlugin({ ???????uglifyOptions: { ?????????compress: { ???????????warnings: false, ???????????// drop_debugger: true, ???????????// drop_console: true ?????????}, ?????????sourceMap: false ???????} ?????}) ???] ?},...}其他的各种报错信息，注意看，可能是模块版本太低了吧，都升级下就OK了。
[完]
vue webpack3 升级webpack4
原文地址：https://www.cnblogs.com/chuchur/p/10462213.html