webpack.config.js

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

module.exports = (env) => {
    const isProduction = env === 'production';
    const CSSExtract = new ExtractTextPlugin('css/styles.css');

    return {
        entry: ['babel-polyfill', './src/app.js'],
        output: {
            path: path.join(__dirname, 'public'),
            filename: 'js/bundle.js'
        },
        module: {
            rules: [
                {
                    loader: 'babel-loader',
                    test: /\.js$/,
                    exclude: /node_modules/
                },
                {
                    test: /\.s?css$/,
                    use: CSSExtract.extract({
                        use: [
                            {
                                loader: 'css-loader',
                                options: {
                                    sourceMap: true
                                }
                            },
                            {
                                loader: 'sass-loader',
                                options: {
                                    sourceMap: true
                                }
                            }
                        ]
                    })
                },
                {
                    test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
                    use: 'url-loader?limit=10000&mimetype=application/font-woff&name=&name=/css/webfonts/[name].[ext]'
                },
                {
                    test: /\.(ttf|eot|svg|otf)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
                    use: 'file-loader?limit=10000&mimetype=application/font-woff&name=&name=/css/webfonts/[name].[ext]'
                }
            ]
        },
        plugins: [
            CSSExtract
        ],
        devtool: isProduction ? 'source-map' : 'cheap-module-eval-source-map',
        devServer: {
            contentBase: path.join(__dirname, 'public'),
            historyApiFallback: true
        }
    };
};