webpack 提取css成单独文件 css兼容性处理 压缩css

npm install mini-css-extract-plugin -D

const  MiniCssExtractPlugin = require(‘mini-css-extract-plugin‘)

plugins: [
        new HtmlWebpackPlugin({
            template:‘./src/index.html‘
        }),
        new MiniCssExtractPlugin({
            filename:‘css/built.css‘//对输出的文件进行重命名,默认为main.css
        })
    ],

{
   test:/\.css$/,
   use:[
      //取代css-loader,提取js中css成单独文件（注意）
       MiniCssExtractPlugin.loader,
       //将css文件整合到JS文件中
      ‘css-loader‘,
   ]
},

npm install postcss-loader postcss-preset-env -D

{
                test:/\.css$/,
                use:[
                    //取代css-loader,提取js中css成单独文件
                    MiniCssExtractPlugin.loader,
                    //将css文件整合到JS文件中
                    ‘css-loader‘,
                    //css兼容性处理：postcss --> postcss-loader postcss-preset-env
                    //帮postcss找到package.json中browserslist里面的配置，通过配置加载指定的css兼容性样式
                    {
                        loader:‘postcss-loader‘,
                        options: {
                            ident: ‘postcss‘,//默认配置
                            plugins: () => [
                                require(‘postcss-preset-env‘)()
                            ]
                        }
                    }
                ]
            },

"browserslist":{
    "development":[
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ],
    "production":[
      ">0.1%",
      "not dead",
      "not op_mini all"
    ]
  }

const {resolve}=require(‘path‘)
const HtmlWebpackPlugin = require(‘html-webpack-plugin‘)

const  MiniCssExtractPlugin = require(‘mini-css-extract-plugin‘)

//设置node.js环境变量,默认是生产环境，配置后为开发环境；
 process.env.NODE_ENV = ‘development‘;

npm install optimize-css-assets-webpack-plugin -D

const OptimizeCssAssetsWebpackPlugin = require(‘optimize-css-assets-webpack-plugin‘)

plugins: [
        new HtmlWebpackPlugin({
            template:‘./src/index.html‘
        }),
        new MiniCssExtractPlugin({
            filename:‘css/built.css‘//对输出的文件进行重命名
        }),
        //压缩css文件
        new OptimizeCssAssetsWebpackPlugin()
    ],