text: const webpack = require('webpack');
  const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
  const MiniCssExtractPlugin = require('mini-css-extract-plugin');
  const CopyWebpackPlugin = require('copy-webpack-plugin');
  const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
  const { merge } = require('webpack-merge');
  // const ImageminPlugin = require('imagemin-webpack-plugin').default;
  const path = require('path');
  
  const baseWebpackConfig = require('./webpack.base.js');
  const config = require('../config');
  const utils = require('./utils');
  
  
  const webpackConfig = merge(baseWebpackConfig, {
    mode: "production",
    module: {
      rules: utils.styleLoaders({
        sourceMap: config.build.productionSourceMap,
        extract: true,
        usePostCSS: true,
      }),
    },
    output: {
      path: config.build.assetsRoot,
      filename: utils.assetsPath('js/[name].[chunkhash].js'),
      chunkFilename: utils.assetsPath('js/[id].[chunkhash].js'),
    },
    optimization: {
      minimize: true,
      minimizer: [
        // For webpack@5 you can use the `...` syntax to extend existing minimizers (i.e. `terser-webpack-plugin`), uncomment the next line
        `...`,
        new CssMinimizerPlugin(),
        new UglifyJsPlugin({
          uglifyOptions: {
            compress: {
              // 删除所有的 `console` 语句，可以兼容ie浏览器
              drop_console: true,
              // 内嵌定义了但是只用到一次的变量
              collapse_vars: true,
              // 提取出出现多次但是没有定义成变量去引用的静态值
              reduce_vars: true,
            },
            output: {
              // 最紧凑的输出
              beautify: true,
              // 删除所有的注释
              comments: true,
            },
          },
        }),
      ],
      runtimeChunk: {
        name: 'manifest',
      },
      splitChunks: {
        cacheGroups: {
          chunks: 'initial', // 只对入口文件处理
          vendor: {
            // test: /([\\/]node_modules[\\/])|([\\/]lib[\\/])/,
            test: /([\\/]node_modules[\\/])/,
            name: 'vendor',
            chunks: 'all',
          },
          'async-vendors': {
            test: /[\\/]node_modules[\\/]/,
            minChunks: 3,
            chunks: 'async',
            name: 'async-vendors',
          },
        },
      },
    },
    plugins: [
      new webpack.DllReferencePlugin({
        context: path.join(__dirname, '..'),
        manifest: require('./vendor-manifest.json'),
      }),
      // 将css提取到它自己的文件中
      new MiniCssExtractPlugin({
        filename: utils.assetsPath('css/[name].[contenthash].css'),
      }),
      new BundleAnalyzerPlugin(),
      // copy custom static assets
      new CopyWebpackPlugin([
        {
          from: path.resolve(__dirname, '../public/static'),
          to: config.build.assetsSubDirectory,
          ignore: ['.*'],
        },
      ]),
    ],
    devtool: false,
    //选项可以控制 webpack 如何通知「资源(asset)和入口起点超过指定文件限制」
    performance: {
      hints: false
    },
  });
  //是否开启gzip
  if (config.build.productionGzip) {
    const CompressionWebpackPlugin = require('compression-webpack-plugin');
    webpackConfig.plugins.push(
      new CompressionWebpackPlugin({
        filename: '[path].gz[query]',
        algorithm: 'gzip',
        test: new RegExp(
          '\\.(' + config.build.productionGzipExtensions.join('|') + ')$'
        ),
        threshold: 10240,
        minRatio: 0.8,
      })
    );
  };
  
  //webpack的可视化资源分析工具
  if (config.build.bundleAnalyzerReport) {
    const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
    webpackConfig.plugins.push(new BundleAnalyzerPlugin());
  };
  
  module.exports = webpackConfig;