webpack.config.js

var path = require("path")
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker')
const CleanWebpackPlugin = require('clean-webpack-plugin');

module.exports = {
  context: __dirname,

  // entry point of our app. assets/js/index.jsx should require other js modules and dependencies it needs
  entry: './assets/js/cobweb', 

  output: {
      path: path.resolve('./assets/bundles/'),
      filename: "[name]-[hash].js",
  },

  plugins: [
    new BundleTracker({filename: './webpack-stats.json'}),
    new CleanWebpackPlugin(['assets/bundles']),
  ],

  module: {
      rules: [      
        {
          test: /\.jsx?$/,
          exclude: /node_modules/,
          use: {
            loader: "babel-loader"
          }
        },
        {
          test: /\.(scss)$/,
          use: [{
            loader: 'style-loader', // inject CSS to page
          }, {
            loader: 'css-loader', // translates CSS into CommonJS modules
          }, {
            loader: 'postcss-loader', // Run post css actions
            options: {
              plugins: function () { // post css plugins, can be exported to postcss.config.js
                return [
                  require('precss'),
                  require('autoprefixer')
                ];
              }
            }
          }, {
            loader: 'sass-loader' // compiles Sass to CSS
          }]
        }
      ]
  },

  resolve: {
    extensions: ['.js', '.jsx']
  }
}