webpack4版本也出了很久了 之前弄過一段時間的升級 后面因為種種原因擱淺了 今天有硬著頭皮升級了一波 yeah 還好升級成功了

先貼一波原先webpack3的github配置

ps（我只是一個菜雞= = webpack的配置很辣雞 ）廢話少說 開擼

1 webpack升級到4.0版本并且安裝webpack-cli

yarn add webpack-cli global<br>yarn add webpack-cli -D

如果不對webpack-cli進行安裝的話會報錯 如下：

The CLI moved into a separate package:webpack-cli.
Please install 'webpack-cli' in addition to webpack itself to use the CLI.
->when using npm: npm install webpack-cli -D
->when using yarn: yarn add webpack-cli -D

2 對一些包的相關依賴

繼續(xù)yarn run dev yeah!!! 報錯了

Error: Cannot find module 'webpack/bin/config-yargs'
at Function.Module._resolveFilename (module.js:538:15)
at Function.Module._load (module.js:468:25)
at Module.require (module.js:587:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\hboxs022\Desktop\webpack-demo\webpack-demo\node_modules\webpack-dev-server\bin\webpack-dev-server.js:54:1)
at Module._compile (module.js:643:30)
at Object.Module._extensions..js (module.js:654:10)
at Module.load (module.js:556:32)
at tryModuleLoad (module.js:499:12)
at Function.Module._load (module.js:491:3)
error Command failed with exit code 1.

解決辦法：這個就是目前版本的webpack-dev-server不支持webpack4 升級一波

yarn add webpack-dev-server@3.1.1 -D //我裝的是3.1.1的包

不過看了挺多資料 只要webpack-dev-server是3.0版本以上好像就兼容 大霧 反正我是3.0.0-alpha6通過了

3 去除commonchunk plugin 改用webpack.optimize.SplitChunksPlugin

再一次執(zhí)行yarn run dev 然后又出錯了 心里一萬個奔騰的野馬 沒辦法啊 硬著頭皮看唄

出錯原因

Error: webpack.optimize.CommonsChunkPlugin has been removed, please use config.optimization.splitChunks instead

webpack4廢除了很多api 之前配置拆分公共代碼 打包第三方庫賊麻煩 然后官方一不做二不休直接廢除了之前的又搗鼓了這個webpack.optimize.SplitChunksPlugin

然后關于這個插件的使用我也是弄了很久后面跑去官方的example里面去看了一下才有所頭緒，如果你之前大致了解原來的commonchunk plugin直接去看官方的例子你就懂了 這里貼一下官方的example鏈接，其中最重要的就是關于如何打包多文件入口的common-chunk-add-vendor-chunk例子，不多說放鏈接直接明了的告訴你如何拆分公用代碼以及第三方庫。

至于打包runtime代碼 webpack4直接調用新的方法 ok 完事

 new webpack.optimize.RuntimeChunkPlugin({
      name: "manifest"
    }),

關于webpack.optimize.SplitChunksPlugin的詳細用法 我也貼出來 有興趣的同學可以自己琢磨

new webpack.optimize.SplitChunksPlugin({
          chunks: "initial", // 必須三選一： "initial" | "all"(默認就是all) | "async"
          minSize: 0, // 最小尺寸，默認0
          minChunks: 1, // 最小 chunk ，默認1
          maxAsyncRequests: 1, // 最大異步請求數(shù)， 默認1
          maxInitialRequests: 1, // 最大初始化請求書，默認1
          name: function () {
          }, // 名稱，此選項可接收 function
          cacheGroups: { // 這里開始設置緩存的 chunks
            priority: 0, // 緩存組優(yōu)先級
            vendor: { // key 為entry中定義的 入口名稱
              chunks: "initial", // 必須三選一： "initial" | "all" | "async"(默認就是異步)
              name: "vendor", // 要緩存的 分隔出來的 chunk 名稱
              minSize: 0,
              minChunks: 1,
              enforce: true,
              maxAsyncRequests: 1, // 最大異步請求數(shù)， 默認1
              maxInitialRequests: 1, // 最大初始化請求書，默認1
              reuseExistingChunk: true // 可設置是否重用該chunk（查看源碼沒有發(fā)現(xiàn)默認值）
            }
          }
        }),

最后貼上修改后的webpack.optimize.SplitChunksPlugin的代碼

new webpack.optimize.SplitChunksPlugin({
      cacheGroups: {
        default: {
          minChunks: 2,
          priority: -20,
          reuseExistingChunk: true,
        },
        //打包重復出現(xiàn)的代碼
        vendor: {
          chunks: 'initial',
          minChunks: 2,
          maxInitialRequests: 5, // The default limit is too small to showcase the effect
          minSize: 0, // This is example is too small to create commons chunks
          name: 'vendor'
        },
        //打包第三方類庫
        commons: {
          name: "commons",
          chunks: "initial",
          minChunks: Infinity
        }
      }
    }),

    new webpack.optimize.RuntimeChunkPlugin({
      name: "manifest"
    }),

4 升級happypack插件?。。。。?/strong>

yarn add webpack-contrib/html-webpack-plugin -D

:\Users\hboxs022\Desktop\webpack4>yarn run dev
yarn run v1.3.2
$ set NODE_ENV=dev && webpack-dev-server
Happy[js]: Version: 5.0.0-beta.3. Threads: 6 (shared pool)
(node:2060) DeprecationWarning: Tapable.plugin is deprecated. Use new API on `.hooks` instead
i ｢wds｣: Project is running at http://localhost:8072/
i ｢wds｣: webpack output is served from /
i ｢wds｣: Content not from webpack is served from C:\Users\hboxs022\Desktop\webpack4\src
Happy[js]: All set; signaling webpack to proceed.
Happy[css]: Version: 5.0.0-beta.3. Threads: 6 (shared pool)
Happy[css]: All set; signaling webpack to proceed.
(node:2060) DeprecationWarning: Tapable.apply is deprecated. Call apply on the plugin directly instead
i ｢wdm｣: wait until bundle finished: /page/index.html
i ｢wdm｣: Hash: 1911cfc871cd5dc27aca
Version: webpack 4.1.1
Time: 9891ms
Built at: 2018-3-28 18:49:25

yarn run build