webpack.common.js

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

const extractSass = new ExtractTextPlugin({
    filename: 'style.css',
    disable: process.env.NODE_ENV === 'development',
});

module.exports = {
    entry: ['babel-polyfill', './src/components/App.js'],
    output: {
        filename: 'bundle.js',
        path: path.resolve(__dirname, 'dist'),
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                loader: 'babel-loader',
            },
            {
                test: /\.scss$/,
                use: extractSass.extract({
                    use: [
                        {
                            loader: 'css-loader',
                            options: {
                                minimize: true,
                            },
                        },
                        {
                            loader: 'sass-loader',
                            options: {
                                includePaths: ['node_modules'],
                            },
                        },
                    ],
                    fallback: 'style-loader',
                }),
            },
            {
                test: /\.svg$/,
                use: [
                    {
                        loader: 'babel-loader',
                    },
                    {
                        loader: 'react-svg-loader',
                        options: {
                            jsx: true,
                        },
                    },
                ],
            },
        ],
    },
    plugins: [
        extractSass,
    ],
};