webpack.config.js

var webpack = require ( "webpack" ),
    path = require ( "path" );

var DIST_DIR = path.resolve ( __dirname, "dist" ),
    SRC_DIR = path.resolve ( __dirname, "src" );

var config = {

    entry: SRC_DIR + "/app/index.js", 

    output: {

        path: DIST_DIR + "/app/",
        filename: "bundle.js",
        publicPath: "/app/"

    },

    module: {

        rules: [

            { test: /\.js$/, exclude: /node_modules/, include: SRC_DIR, loader: 'babel-loader' }

        ]

    }

}

module.exports = config;