第十九章 webpack5项目搭建Vue-Cli(合并配置)

对于开发环境的配置和生产环境的配置，有大部分代码配置是重复的，因此我们希望将配置合并减少代码体积。

对于Vue-Cli的合并配置，我们使用webpack.prod.js进行改造。

step1--判断环境类型

对于什么时候是开发环境，什么时候是生产环境，我们可以通过process.env.NODE_ENV的值来判断。

// 需要通过 cross-env 定义环境变量
const isProduction = process.env.NODE_ENV === "production";

step2--修改输出目录与命名方式

 output: {
    path: isProduction ? path.resolve(__dirname, "../dist") : undefined,
    filename: isProduction
      ? "static/js/[name].[contenthash:10].js"
      : "static/js/[name].js",
    chunkFilename: isProduction
      ? "static/js/[name].[contenthash:10].chunk.js"
      : "static/js/[name].chunk.js",
    assetModuleFilename: "static/js/[hash:10][ext][query]",
    clean: true,
  },

step3--判断CSS是否提取为单独文件

const getStyleLoaders = (preProcessor) => {
  return [
    isProduction ? MiniCssExtractPlugin.loader : "style-loader",
    "css-loader",
    {
      loader: "postcss-loader",
      options: {
        postcssOptions: {
          plugins: [
            "postcss-preset-env", // 能解决大多数样式兼容性问题
          ],
        },
      },
    },
    preProcessor,
  ].filter(Boolean);
};

过滤插件：

plugins: [
   //...
    isProduction &&
      new MiniCssExtractPlugin({
        filename: "static/css/[name].[contenthash:10].css",
        chunkFilename: "static/css/[name].[contenthash:10].chunk.css",
      }),
  ].filter(Boolean),

step4--判断模式的值

mode: isProduction ? "production" : "development",

step5--判断sourceMap的值

devtool: isProduction ? "source-map" : "cheap-module-source-map",

step6--判断是否开启代码压缩

 optimization: {
    minimize: isProduction,
    // ...
 }

如果是生产环境就开启代码压缩，反之则关闭

step7--引入DevServer

devServer: {
    open: true,
    host: "localhost",
    port: 3000,
    hot: true,
    compress: true,
    historyApiFallback: true,
  },

step8--现阶段的详细配置代码

// webpack.config.js
const path = require("path");
const ESLintWebpackPlugin = require("eslint-webpack-plugin");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CssMinimizerPlugin = require("css-minimizer-webpack-plugin");
const TerserWebpackPlugin = require("terser-webpack-plugin");
const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");
const { VueLoaderPlugin } = require("vue-loader");
const { DefinePlugin } = require("webpack");
const CopyPlugin = require("copy-webpack-plugin");

// 需要通过 cross-env 定义环境变量
const isProduction = process.env.NODE_ENV === "production";

const getStyleLoaders = (preProcessor) => {
  return [
    isProduction ? MiniCssExtractPlugin.loader : "vue-style-loader",
    "css-loader",
    {
      loader: "postcss-loader",
      options: {
        postcssOptions: {
          plugins: ["postcss-preset-env"],
        },
      },
    },
    preProcessor,
  ].filter(Boolean);
};

module.exports = {
  entry: "./src/main.js",
  output: {
    path: isProduction ? path.resolve(__dirname, "../dist") : undefined,
    filename: isProduction
      ? "static/js/[name].[contenthash:10].js"
      : "static/js/[name].js",
    chunkFilename: isProduction
      ? "static/js/[name].[contenthash:10].chunk.js"
      : "static/js/[name].chunk.js",
    assetModuleFilename: "static/js/[hash:10][ext][query]",
    clean: true,
  },
  module: {
    rules: [
      {
        // 用来匹配 .css 结尾的文件
        test: /\.css$/,
        // use 数组里面 Loader 执行顺序是从右到左
        use: getStyleLoaders(),
      },
      {
        test: /\.less$/,
        use: getStyleLoaders("less-loader"),
      },
      {
        test: /\.s[ac]ss$/,
        use: getStyleLoaders("sass-loader"),
      },
      {
        test: /\.styl$/,
        use: getStyleLoaders("stylus-loader"),
      },
      {
        test: /\.(png|jpe?g|gif|svg)$/,
        type: "asset",
        parser: {
          dataUrlCondition: {
            maxSize: 10 * 1024, // 小于10kb的图片会被base64处理
          },
        },
      },
      {
        test: /\.(ttf|woff2?)$/,
        type: "asset/resource",
      },
      {
        test: /\.(jsx|js)$/,
        include: path.resolve(__dirname, "../src"),
        loader: "babel-loader",
        options: {
          cacheDirectory: true,
          cacheCompression: false,
          plugins: [
            // "@babel/plugin-transform-runtime" // presets中包含了
          ],
        },
      },
      // vue-loader不支持oneOf
      {
        test: /\.vue$/,
        loader: "vue-loader", // 内部会给vue文件注入HMR功能代码
        options: {
          // 开启缓存
          cacheDirectory: path.resolve(
            __dirname,
            "node_modules/.cache/vue-loader"
          ),
        },
      },
    ],
  },
  plugins: [
    new ESLintWebpackPlugin({
      context: path.resolve(__dirname, "../src"),
      exclude: "node_modules",
      cache: true,
      cacheLocation: path.resolve(
        __dirname,
        "../node_modules/.cache/.eslintcache"
      ),
    }),
    new HtmlWebpackPlugin({
      template: path.resolve(__dirname, "../public/index.html"),
    }),
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, "../public"),
          to: path.resolve(__dirname, "../dist"),
          toType: "dir",
          noErrorOnMissing: true,
          globOptions: {
            ignore: ["**/index.html"],
          },
          info: {
            minimized: true,
          },
        },
      ],
    }),
    isProduction &&
      new MiniCssExtractPlugin({
        filename: "static/css/[name].[contenthash:10].css",
        chunkFilename: "static/css/[name].[contenthash:10].chunk.css",
      }),
    new VueLoaderPlugin(),
    new DefinePlugin({
      __VUE_OPTIONS_API__: "true",
      __VUE_PROD_DEVTOOLS__: "false",
    }),
  ].filter(Boolean),
  optimization: {
    minimize: isProduction,
    // 压缩的操作
    minimizer: [
      new CssMinimizerPlugin(),
      new TerserWebpackPlugin(),
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminGenerate,
          options: {
            plugins: [
              ["gifsicle", { interlaced: true }],
              ["jpegtran", { progressive: true }],
              ["optipng", { optimizationLevel: 5 }],
              [
                "svgo",
                {
                  plugins: [
                    "preset-default",
                    "prefixIds",
                    {
                      name: "sortAttrs",
                      params: {
                        xmlnsOrder: "alphabetical",
                      },
                    },
                  ],
                },
              ],
            ],
          },
        },
      }),
    ],
    splitChunks: {
      chunks: "all",
    },
    runtimeChunk: {
      name: (entrypoint) => `runtime~${entrypoint.name}`,
    },
  },
  resolve: {
    extensions: [".vue", ".js", ".json"],
  },
  devServer: {
    open: true,
    host: "localhost",
    port: 3000,
    hot: true,
    compress: true,
    historyApiFallback: true, // 解决vue-router刷新404问题
  },
  mode: isProduction ? "production" : "development",
  devtool: isProduction ? "source-map" : "cheap-module-source-map",
};