css优化 optimize-css-assets-webpack-plugin

将多个相同的css选择器合并

const OptimizeCssAssetsAebpackPlugin = require('optimize-css-assets-webpack-plugin')
   plugins: [
        new MiniCssExtractPlugin({//抽离css
            filename: "css/[name].css",//css打包后的名字
            chunkFilename: 'css/[id].css',//import 动态引入时  id没有配置引入名则以1 2 3 4 5 命名 import(/*webpackChunckName: a*/ './style.css')
        }),
        new OptimizeCssAssetsAebpackPlugin({
            assetNameRegExp: /\.css/g,//.css文件结尾
            cssProcessor: require('cssnano'),//默认会安装cssnano  使用 OptimizeCssAssetsAebpackPlugin调用cssnano
            cssProcessorPluginOptions: {
                preset: [
                    "default",
                    {
                        discardComments: {
                            removeAll: true
                        }
                    }
                ]
            },
            canPrint: true,//
        }),
    ],