webpack.config.js

//require our dependencies
var path = require('path')
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker')

module.exports = {
    //the base directory (absolute path) for resolving the entry option
    context: __dirname,
    //the entry point we created earlier. Note that './' means 
    //your current directory. You don't have to specify the extension  now,
    //because you will specify extensions later in the `resolve` section
    entry: './assets/js/index', 
    
    output: {
        //where you want your compiled bundle to be stored
        path: path.resolve('./assets/bundles/'), 
        //naming convention webpack should use for your files
        filename: '[name]-[hash].js', 
    },
    
    plugins: [
        //tells webpack where to store data about your bundles.
        new BundleTracker({filename: './webpack-stats.json'}), 
        //makes jQuery available in every module
        new webpack.ProvidePlugin({ 
            $: 'jquery',
            jQuery: 'jquery',
            'window.jQuery': 'jquery' 
        })
    ],
    
    module: {
        loaders: [
            //a regexp that tells webpack use the following loaders on all 
            //.js and .jsx files
            {test: /\.jsx?$/, 
                //we definitely don't want babel to transpile all the files in 
                //node_modules. That would take a long time.
                exclude: /node_modules/, 
                //use the babel loader 
                loader: 'babel-loader', 
                query: {
                    //specify that we will be dealing with React code
                    presets: ['react'] 
                }
            }
        ]
    },
    
    resolve: {
        //tells webpack where to look for modules
        modules: [__dirname, 'node_modules'],
        //extensions that should be used to resolve modules
        extensions: ['*', '.js', '.jsx'],
        alias: {
            "react": "preact-compat",
            "react-dom": "preact-compat"
        }
    }   
}