Add webpack code splitting module

Add cold-module replacement
Add webpack module hashing

webpack.config.js

@@ -1,13 +1,20 @@
 var webpack = require('webpack');
 var path = require('path');
+var ManifestPlugin = require('webpack-manifest-plugin');
+var ChunkManifestPlugin = require('chunk-manifest-webpack-plugin');
 
 var __DEV__ = process.env.NODE_ENV !== 'production';
 
 module.exports = {
-  entry: './client',
-  devtool: 'inline-source-map',
+  entry: {
+    bundle: './client'
+  },
+  devtool: __DEV__ ? 'inline-source-map' : null,
   output: {
-    filename: 'bundle.js',
+    filename: __DEV__ ? 'bundle.js' : 'bundle-[hash].js',
+    chunkFilename: __DEV__ ?
+      'bundle-[name].js' :
+      'bundle-[name]-[chunkhash].js',
     path: path.join(__dirname, '/public/js'),
     publicPath: __DEV__ ? 'http://localhost:2999/js' : '/js'
   },
@@ -42,8 +49,21 @@ module.exports = {
         'NODE_ENV': JSON.stringify(__DEV__ ? 'development' : 'production')
       },
       '__DEVTOOLS__': !__DEV__
-    }),
-    new webpack.HotModuleReplacementPlugin(),
-    new webpack.NoErrorsPlugin()
+    })
   ]
 };
+
+if (!__DEV__) {
+  module.exports.plugins.push(
+    new ManifestPlugin({ fileName: 'react-manifest.json' }),
+    new ChunkManifestPlugin({
+      filename: 'chunk-manifest.json',
+      manifestVariable: 'webpackManifest'
+    })
+  );
+} else {
+  module.exports.plugins.push(
+    new webpack.HotModuleReplacementPlugin(),
+    new webpack.NoErrorsPlugin()
+  );
+}