Help setting up WebPack & Babel. Gets Uncaught ReferenceError: function is not defined

I’m just getting started with Webpack & Babel to take advantage of exporting ES6’s modules.

My build setup generates build/ used in index.html but browser console shows error: Uncaught ReferenceError: calculateInterest is not defined

As, I’m new to this, I’m not sure where the problem actually lies, is it in the my webpack.config.js or package.json setup or the exporting and importing modules or in the compiled build/

Can anybuddy help me get this setup right. Here are the build files.


  "name": "learn-webpack",
  "version": "1.0.0",
  "description": "A shot at learning WebPack",
  "main": "index.html",
  "scripts": {
    "start": "http-server",
    "webpack": "webpack"
  "keywords": [
  "author": "",
  "license": "ISC",
  "dependencies": {
    "webpack": "^4.16.1"
  "devDependencies": {
    "babel-cli": "^6.26.0",
    "babel-core": "^6.26.3",
    "babel-loader": "^7.1.5",
    "babel-preset-es2015": "^6.24.1",
    "http-server": "^0.11.1",
    "webpack": "^4.16.1",
    "webpack-cli": "^3.1.0"


const path = require('path') 

module.exports = {
    entry: './scripts/main.js',
    output: {
        path: path.resolve(__dirname, 'build'),
        filename: 'main.bundle.js'

    module: {
         rules: [
                 test: /\.js$/,
                 use: [{
                    loader: 'babel-loader',
                    query: {
                         presets: ['es2015']
     optimization: {
        minimize: false

     mode: 'development',

     stats: {
         colors: true


    <title>Babel Learning</title>
    <link href="css/style.css" type="text/css" rel="stylesheet">
    <script src="build/main.bundle.js" type="text/javascript"></script> 
<body onload="init()">

    <button id="btn">Calculate Interest</button>

    <div id="result"></div>

    function init() {
        var btn = document.getElementById('btn')
        var result = document.getElementById('result')

        btn.addEventListener('click', function(){
            var interest = calculateInterest(3000,29,1)
            result.innerHTML = interest



import getSI from './js/getSI.js'


export function calculateInterest(principal, rate, time) {
    var interest = (principal * rate * time) / 100
    return interest

Thanks for your help. Much appreciated.


I suspect the problem is in your .js files

You don’t have a default export, and the name of the export doesn’t match it

I think you either meant to do export default and import calculateInterest or import {calculateInterest} (note the braces)