webpack.config.js

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

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

module.exports = {
  entry: ['./source/scss/style.scss', './source/js/ribs-checkbox.js'],
  output: {
    filename: 'js/ribs-checkbox.js'
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        include: [path.join(__dirname, 'source/'), path.join(__dirname, 'node_modules/ribs-core/')],
        loader: 'babel-loader',
      },
      {
        test: /\.scss$/,
        exclude: /node_modules/,
        use: extractSass.extract({
          use: [
            {loader: 'css-loader'},
            {loader: 'sass-loader'}
          ],
          fallback: "style-loader"
        })
      }
    ]
  },
  plugins: [
    new UglifyJsPlugin(),
    extractSass
  ]
};