Tree-Shaking with Babel 6, Webpack 2, and React.

.babelrc

{
  "presets": [
    ["es2015", {
      "es2015": {
        "loose": true,
        "modules": false
      }
    }], "react"
  ]
}

app.js

import React from 'react';
import ReactDOM from 'react-dom';

const App = React.createClass({
  render() {
    return (
      <div>Hello World</div>
    );
  }
});

ReactDOM.render(<App/>, document.querySelector('#app'));

package.json

{
  "name": "babel6-webpack2-react-tree-shaking",
  "version": "0.0.0",
  "dependencies": {},
  "devDependencies": {
    "babel-core": "6.18.2",
    "babel-loader": "6.2.8",
    "babel-preset-es2015": "6.18.0",
    "babel-preset-react": "6.16.0",
    "babili": "0.0.9",
    "babili-webpack-plugin": "0.0.7",
    "http-server": "0.9.0",
    "react": "15.4.1",
    "react-dom": "15.4.1",
    "webpack": "2.1.0-beta.27"
  },
  "scripts": {
    "build": "webpack --config webpack.config.js",
    "start": "http-server -a 0.0.0.0 -p 9000"
  }
}

webpack.config.js

const BabiliPlugin = require('babili-webpack-plugin');
const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: {
    'app': './app.js'
  },
  output: {
    path: './dist',
    filename: '[name].bundle.js'
  },
  module: {
    rules: [{
      test: /\.js$/,
      loader: 'babel-loader',
      query: {
        presets: [
          'es2015',
          'react'
        ],
        plugins: []
      },
      include: [
        path.resolve(__dirname, 'app')
      ]
    }, {
      test: /\.json$/,
      loader: "json-loader"
    }]
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'production')
    }),
    new BabiliPlugin()
  ],
  resolve: {
    modules: [
      path.join(process.cwd(), 'app'),
      'node_modules'
    ],
    extensions: ['.js', '.json']
  },
  devtool: false
};