webpack 2.x strict mode (with harmony imports)

webpack.config.js

"use strict";
var ConcatSource = require("webpack-sources").ConcatSource;

class StrictPlugin {
  constructor(options){
    this.options = options;
  }
  apply(compiler) {
    compiler.plugin("compilation", compilation=>{
      compilation.moduleTemplate.plugin("render", (moduleSource, module, chunk, dependencyTemplates)=>{
        if (module.resource && module.resource.startsWith(this.options.root)) {
          return new ConcatSource("\"use strict\";\n", moduleSource);
        }
        return moduleSource;
      });
      compilation.moduleTemplate.plugin("hash", hash=>{
        hash.update("StrictPlugin");
        hash.update("1");
      });
    });
  }
}

module.exports = {
    entry: "./lib/main",
    output: {
      path: __dirname + "/dist",
            filename: 'bundle.js'
    },
    plugins: [
      new StrictPlugin({ root: __dirname+"/lib" })
    ]
}