在不明白CommonsChunkPlugin的使用狀況下,直接上手webpack4的splitChunks,實在是難上加難。爲了能更好的理解splitChunks的使用,必須出個題目,練練手,才能從中有所收穫(下面的題目不考慮實際應用場景):webpack
entry: { index:'./src/index.js', index1:'./src/index1.js', index2:'./src/index2.js' }, plugins: [ new CommonsChunkPlugin({ name:"common1", chunks:['index','index1','index2'] }) ]
其中index和index1以及index2都是打包的入口文件。web
optimization: { splitChunks: { chunks:"all", minSize: 0, cacheGroups: { common: { minChunks: 3, priority: -1, name:'common', chunks (chunk) { // exclude `my-excluded-chunk` return ['index','index1','index2'].includes(chunk.name); } } } } }
在cacheGroups下面咱們定義了一個common。經過chunks函數,指定三個入口文件爲:'index','index1','index2',同時咱們還要設置minChunks爲3,表示指定三個入口文件中提取出的公共文件,最少要被三個不一樣的入口文件引用。因此就是從三個入口文件中提取公共的文件。app
先說一下,這是什麼意思:函數
下面給出webpack3 和webpack4下的處理code
new CommonsChunkPlugin({ name:"common1", chunks:['index','index1','index2'] }), new CommonsChunkPlugin({ name:"common2", chunks:['app','app1','app2'] }), new CommonsChunkPlugin({ name:"common3", chunks:['common1','common2'] })
很清楚,先從'index','index1','index2'中提取公共文件‘common1’,再從'app','app1','app2'中提取公共文件‘common2’。最後從‘common1’和‘common2’中再提取出公共文件common3。webpack4
optimization: { runtimeChunk: 'single', splitChunks: { chunks:"all", minSize: 0, cacheGroups: { common3: { minChunks: 6, priority: 1, reuseExistingChunk: true }, common2: { minChunks: 3, priority: -2, name:'common2', chunks (chunk) { // exclude `my-excluded-chunk` return ['app','app1','app2'].includes(chunk.name); } }, common1: { priority: -1, name: 'common1', minChunks: 3, enforce: true, chunks (chunk) { return ['index','index1','index2'].includes(chunk.name); } } } } }
我沒有從文檔中找到:提取公共文件以後再處理的方法。因此我用了另一種方式:文檔