Webpack, how to take out module into his own build layer?

Question

With default build settings I get following build layers: (X+A), (Y+A+B), (Z+B).

I want: (X+A), (Y+A), Z, B

B should load only once when we asking Y and Z modules.

I found CommonsChunkPlugin, but I cant configure it properly.

var webpack = require("webpack");
var CommonsPlugin = new require("webpack/lib/optimize/CommonsChunkPlugin");

module.exports = {
    entry: {
        main: "./main"
    },
    resolve: {
        modulesDirectories: [
            "."
        ]
    },
    output: {
        publicPath: "js/",
        filename: "[name].builded.js"
    },
    plugins: [
           new CommonsPlugin({
            //  What should I write here?
            })
    ]
};

Answer 1

Looks like you should add B as separate entry point:

entry: {
   main: "./main",
   Bentry: ["B"]
},

and add CommonsChunkPlugin in plugins section:

new webpack.optimize.CommonsChunkPlugin('Bentry', 'B.js'),