CommonsChunkPlugin的实现：
entry: {
    index:'./src/index.js',
    index1:'./src/index1.js',
    index2:'./src/index2.js'
},
plugins: [
  new CommonsChunkPlugin({
    name:"common1",
    chunks:['index','index1','index2']
  })
]

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);
          }
        }
      }
    }
  }

new CommonsChunkPlugin({
  name:"common1",
  chunks:['index','index1','index2']
}),
new CommonsChunkPlugin({
  name:"common2",
  chunks:['app','app1','app2']
}),
new CommonsChunkPlugin({
  name:"common3",
  chunks:['common1','common2']
})

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);
          }
        }
      }
    }
  }