14-压缩css

const { resolve } = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const OptimizeCssAssetsWebpackPlugin = require('optimize-css-assets-webpack-plugin')
 
// 设置nodejs环境变量
// process.env.NODE_ENV = 'development'
 
module.exports = {
  entry: './src/js/index.js',
  output: {
    filename: 'js/built.js',
    path: resolve(__dirname, 'build')
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          MiniCssExtractPlugin.loader,
          'css-loader',
          /**
           * css兼容性处理：postcss --> postcss-loader postcss-preset-env
           *
           * 帮postcss找到package.json中的browserslist里面的配置，通过配置加载指定的css兼容性样式
           *
           * "browserslist": {
           *    // 开发环境 --> 设置node环境变量：process.env.NODE_ENV = development
           *    "development": [
           *       "last 1 chrome version",
           *       "last 1 firefox version",
           *       "last 1 safari version"
           *     ],
           *    // 生产环境：默认是看生产环境
           *    "production": [
           *       ">0.2%",
           *       "not dead",
           *        "not op_mini all"
           *     ]
           *  }
           *
           */
          // 使用loader的默认配置
          // 'postcss-loader',
          // 修改loader的配置
          {
            loader: 'postcss-loader',
            options: {
              ident: 'postcss',
              plugins: () => [
                // postcss的插件
                require('postcss-preset-env')()
              ]
            }
          }
        ]
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './src/index.html'
    }),
    new MiniCssExtractPlugin({
      filename: 'css/build.css'
    }),
    // 压缩css
    new OptimizeCssAssetsWebpackPlugin()
  ],
  mode: 'development'
}