webpack.config.js

// module.exports = {
//     entry: './src/app',
//     output: {
//         filename: './dist/app.bundle.js'
//     }
// }

var webpack = require('webpack');
var path = require('path');

var BUILD_DIR = path.join(__dirname, 'dist');
var APP_DIR = path.join(__dirname, 'src');


var config = {
    entry: APP_DIR + '/app.js',
    output: {
        path: BUILD_DIR,  
        filename: 'bundle.js'
    },
    module: {
        rules: [{
            test: /\.(js|jsx)$/,
            //include: APP_DIR,
            exclude: /node_modules/,
            use: 'babel-loader'
        },
        {
            test: /\.css$/,
            use: ['style-loader', 'css-loader']
        },
        {
            test: /\.scss$/,
            use: ['style-loader', 'css-loader', 'sass-loader']
        },
        {
            test: /\.(jpe?g|png|gif|svg)$/i,
            use: 'file-loader'
        }
    ]
    },
    devServer: {
        contentBase: BUILD_DIR,
        compress: true,
        port: 9000,
        disableHostCheck: false,
        open: true,
        hot: true
    },
    plugins: [
        new webpack.HotModuleReplacementPlugin()
    ]
}

module.exports = config;