webpack配置提取公共代码

公共代码提取功能是针对多入口文件的；

　　背景：在pageA.js和pageB.js中分别引用subPageA.js和subPageB.js

　　webpack.config.js文件：

 var path = require('path')
 module.exports = {
     entry:{
         pageA:'./src/pageA.js',
         pageB:'./src/pageB.js'
     },
     output: {
         filename: "[name].js",
         path:path.resolve(__dirname,'./dist')
     },
     optimization: {
         splitChunks:{
             cacheGroups: {
                 vender:{
                     test:/node_modules/,
                     chunks:'initial',
                     name:'vender',
                     priority:10
                 },
                 utils:{
                     chunks:'initial',
                     name:'utils',
                     minSize:0
                 }
             }
         }
     }
 }