英語資料を読むのが面倒な人のためのwebpack 2移行ガイド ref: http://qiita.com/potato4d/items/4975c3d9c5fe56fa78c1

file2.js

const services = []
const serviceList = ["serviceA", "serviceB", "serviceD"];
serviceList.map((s)=>{
  System.import("./services/" + s)
  .then((mod)=>{
    services.push(mod);
  })
});

file3.txt

$ rm -Rf ./node_modules/

file_a.js

import "./file_b" // これで動く
file_b("hoge")

file_b.js

export default function(word){console.log(word)}

webpack.config.after.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.css/,
        use: "css-loader"
      }
    ]
  }
}

webpack.config.before.js

module.exports ={
  module: {
    loaders: [
     {
       test: /\.css/,
       use: "css"
     }
    ]
  }
}