const merge = require('webpack-merge');
const path = require('path');
const webpack = require('webpack');

const TARGET = process.env.npm_lifecycle_event;
const PATHS = {
  app: path.join(__dirname, 'app'),
  build: path.join(__dirname, 'build')
};

const common = {
  // Entry accepts a path or an object of entries. We'll be using the
  // latter form given it's convenient with more complex configurations.
  entry: {
    app: PATHS.app
  },
  output: {
    path: PATHS.build,
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        // Test expects a RegExp! Note the slashes!
        test: /\.css$/,
        loaders: ['style', 'css'],
        // Include accepts either a path or an array of paths.
        include: PATHS.app
      }
    ]
  }
};

if (TARGET === 'start' || !TARGET) {
  module.exports = merge(common, {
    devServer: {
      contentBase: PATHS.build,
        // Enable history API fallback so HTML5 History API based
        // routing works. This is a good default that will come
        // in handy in more complicated setups.
        historyApiFallback: true,
        hot: true,
        inline: true,
        progress: true,

        // Display only errors to reduce the amount of output.
        stats: 'errors-only',

        // Parse host and port from env so this is easy to customize.
        //
        // If you use Vagrant or Cloud9, set
        // host: process.env.HOST || '0.0.0.0';
        //
        // 0.0.0.0 is available to all network devices unlike default
        // localhost
        host: process.env.HOST,
        port: process.env.PORT
      },
      plugins: [
        new webpack.HotModuleReplacementPlugin()
      ]
  });
}

if(TARGET === 'build') {
  module.exports = merge(common, {});
}

@@ -834,16 +834,48 @@
 mmon, %7B%0A
+    devtool: 'eval-source-map',%0A
     devS

Add source maps