webpack 提取页面公共资源

基础库分离

• 思路路:将 react、react-dom 基础 包通过 cdn 引⼊入，不不打⼊入 bundle 中
• ⽅方法:使⽤用 html-webpack- externals-plugin

const HtmlWebpackExternalPlugin = require('html-webpack-externals-plugin');

plugins: [
  new HtmlWebpackExternalPlugin([
    {
      module: 'react',
      entry: 'https://unpkg.com/react@16/umd/react.development.js',
      global: 'React',
    },
    {
      module: 'react-dom',
      entry: 'https://unpkg.com/react-dom@16/umd/react-dom.development.js',
      global: 'ReactDOM'
    }
  ])
]

利用 SplitChunksPlugin 进行公共脚本分离

Webpack4 内置的，替代CommonsChunkPlugin插件

chunks 参数说明:

• async 异步引⼊入的库进⾏行行分离(默认)
• initial 同步引⼊入的库进⾏行行分离
• all 所有引⼊入的库进⾏行行分离(推荐)

module.exports = {
  optimization: {
    splitChunks: {
      chunks: "async",
      minSize: 30000,
      maxSize: 0,
      minChunks: 1,
      maxAsyncRequests: 5,
      maxInitialRequests: 3,
      automaticNameDelimiter: "~",
      name: true,
      cacheGroups: {
        vendors: {
          test: /[\\/]node_modules[\\/]/,
          priority: -10,
        },
      },
    },
  },
};

利用 SplitChunksPlugin 分离基础包

test: 匹配出需要分离的包

module.exports = {
  optimization: {
    splitChunks: {
      cacheGroups: {
        commons: {
          test: /(react|react-dom)/,
          name: "vendors",
          chunks: "all",
        },
      },
    },
  },
};

利利⽤用 SplitChunksPlugin 分离⻚页⾯面公共⽂文件

minChunks: 设置最⼩小引⽤用次数为2次

minuSize: 分离的包体积的⼤大⼩小

module.exports = {
  optimization: {
    splitChunks: {
      minSize: 0,
      cacheGroups: {
        commons: {
          name: "commons",
          chunks: "all",
          minChunks: 2,
        },
      },
    },
  },
};

完整的webpack.prod.js

'use strict';

const glob = require('glob');
const path = require('path');
const webpack = require('webpack');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const HtmlWebpackExternalsPlugin = require('html-webpack-externals-plugin');

const setMPA = () => {
    const entry = {};
    const htmlWebpackPlugins = [];
    const entryFiles = glob.sync(path.join(__dirname, './src/*/index.js'));

    Object.keys(entryFiles)
        .map((index) => {
            const entryFile = entryFiles[index];
            // '/Users/cpselvis/my-project/src/index/index.js'

            const match = entryFile.match(/src\/(.*)\/index\.js/);
            const pageName = match && match[1];

            entry[pageName] = entryFile;
            htmlWebpackPlugins.push(
                new HtmlWebpackPlugin({
                    inlineSource: '.css$',
                    template: path.join(__dirname, `src/${pageName}/index.html`),
                    filename: `${pageName}.html`,
                    chunks: ['vendors', pageName],
                    inject: true,
                    minify: {
                        html5: true,
                        collapseWhitespace: true,
                        preserveLineBreaks: false,
                        minifyCSS: true,
                        minifyJS: true,
                        removeComments: false
                    }
                })
            );
        });

    return {
        entry,
        htmlWebpackPlugins
    }
}

const { entry, htmlWebpackPlugins } = setMPA();

module.exports = {
    entry: entry,
    output: {
        path: path.join(__dirname, 'dist'),
        filename: '[name]_[chunkhash:8].js'
    },
    mode: 'production',
    module: {
        rules: [
            {
                test: /.js$/,
                use: [
                    'babel-loader',
                    // 'eslint-loader'
                ]
            },
            {
                test: /.css$/,
                use: [
                    MiniCssExtractPlugin.loader,
                    'css-loader'
                ]
            },
            {
                test: /.less$/,
                use: [
                    MiniCssExtractPlugin.loader,
                    'css-loader',
                    'less-loader',
                    {
                        loader: 'postcss-loader',
                        options: {
                            plugins: () => [
                                require('autoprefixer')({
                                    browsers: ['last 2 version', '>1%', 'ios 7']
                                })
                            ]
                        }
                    },
                    {
                        loader: 'px2rem-loader',
                        options: {
                            remUnit: 75,
                            remPrecision: 8
                        }
                    }
                ]
            },
            {
                test: /.(png|jpg|gif|jpeg)$/,
                use: [
                    {
                        loader: 'file-loader',
                        options: {
                            name: '[name]_[hash:8].[ext]'
                        }
                    }
                ]
            },
            {
                test: /.(woff|woff2|eot|ttf|otf)$/,
                use: [
                    {
                        loader: 'file-loader',
                        options: {
                            name: '[name]_[hash:8][ext]'
                        }
                    }
                ]
            }
        ]
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename: '[name]_[contenthash:8].css'
        }),
        new OptimizeCSSAssetsPlugin({
            assetNameRegExp: /\.css$/g,
            cssProcessor: require('cssnano')
        }),
        new CleanWebpackPlugin(),
        new HtmlWebpackExternalsPlugin({
            externals: [
              {
                module: 'react',
                entry: 'https://11.url.cn/now/lib/16.2.0/react.min.js',
                global: 'React',
              },
              {
                module: 'react-dom',
                entry: 'https://11.url.cn/now/lib/16.2.0/react-dom.min.js',
                global: 'ReactDOM',
              },
            ]
        })  
    ].concat(htmlWebpackPlugins),
};