webpack.config.js

const path = require( 'path' );
const HTMLWebpackPlugin = require( 'html-webpack-plugin' );

module.exports = {

    // webpack optimization mode
    mode: ( 'development' === process.env.NODE_ENV ? 'development' : 'production' ),

    // entry files
    entry: [
        './src/index.js', // react
    ],

    // output files and chunks
    output: {
        path: path.resolve( __dirname, 'dist' ),
        filename: '[name].js'
    },

    // module/loaders configuration
    module: {
        rules: [
            {
                test: /\.jsx?$/,
                exclude: /node_modules/,
                use: [ 'babel-loader' ]
            }
        ]
    },

    // webpack plugins
    plugins: [

        // prepare HTML file with assets
        new HTMLWebpackPlugin( {
            filename: 'index.html',
            template: path.resolve( __dirname, 'src/index.html' )
        } ),
    ],

    // resolve files configuration
    resolve: {
        
        // file extensions
        extensions: [ '.js', '.jsx' ]
    },

    // development server configuration
    devServer: {
        port: 9000
    },

};