webpack.base.js

const ExtractTextPlugin = require('extract-text-webpack-plugin');

const nodeEnv = process.env.NODE_ENV;
const webpack = require('webpack');


module.exports = {
  // Enable webpack to run babel on every file
  module: {
    rules: [
      {
        test: /\.js?$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        options: {
          presets: [
            'react',
            'stage-0',
            ['env',
              {
                targets: {
                  browsers: ['last 2 versions'],
                },
              },
            ],
          ],

        },
      },
      {
        test: /\.(jpg|png|gif|svg)$/,
        loader: 'image-webpack-loader',
        options: {
          mozjpeg: {
            progressive: true,
            quality: 65,
          },
          // optipng.enabled: false will disable optipng
          optipng: {
            enabled: false,
          },
          pngquant: {
            quality: '65-90',
            speed: 4,
          },
          gifsicle: {
            interlaced: false,
          },
          // the webp option will enable WEBP
          webp: {
            quality: 75,
          },
        },
      },
      {
        test: /\.(sass|scss)$/,
        loader: ExtractTextPlugin.extract(['css-loader', 'sass-loader']),
      },
      {
        exclude: /\.scss?$/,
        test: /\.(png|jpg)$/,
        loader: 'url-loader',
      },
    ],
  },
  plugins: nodeEnv !== 'production' ? [
    new ExtractTextPlugin({ // define where to save the file
      filename: 'main.bundle.css',
      allChunks: true,
    }),
  ] : [
    new ExtractTextPlugin({ // define where to save the file
      filename: 'main.bundle.css',
      allChunks: true,
    }),
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('production'),
    }),
    new webpack.optimize.UglifyJsPlugin({
      sourceMap: true,
    }),
  ],
};