Tirithen February 2016

Webpack fails to build ES6 in external packages

I'm trying to use an ES6 npm package (in this case one called gamesystem) in a project and build with webpack (and babel) it fails to build any ES6 code inside the external dependency, why is that? If I have the same code as a dependency with a relative path it works fine.

App code:

'use strict';

import World from 'gamesystem'; // Breaks
//import World from '../node_modules/gamesystem'; // Also breaks
//import World from '../gamesystem'; // Works (copied the same directory gamesystem outside the node_modules directory)

let world = new World();


ERROR in ./~/gamesystem/World.js
Module parse failed: /home/user/project/node_modules/gamesystem/World.js Line 3: Unexpected token
You may need an appropriate loader to handle this file type.
| 'use strict';
| import System from './System';
| export default class World {
 @ ./src/app.js 3:18-39

Webpack config:

'use strict';

// Modules
let WebpackNotifierPlugin = require('webpack-notifier');
let HtmlWebpackPlugin = require('html-webpack-plugin');

let config = {
  entry: {
    app: __dirname + '/../src/app.js'
  devtool: 'source-map',
  devServer: {
    stats: {
      modules: false,
      cached: false,
      colors: true,
      chunk: false
    proxy: require('./devProxy')
  module: {
    loaders: [{
      test: /\.js$/,
      loader: 'babel',
      exclude: /node_modules/,
      query: {
        presets: ['es2015', 'stage-0']
      test: /\.css$/,
      loader: 'style!css'
      test: /\.html$/,
      loader: 'raw'
  plugins: [
    new WebpackNotifierPlugin(),
    new HtmlWebpackPlugin({
      template: __dirname + '/../src/index.html',
      inject: 'body',
      minify: false

module.exports = config;


Jon Surrell February 2016

You're explicitly excluding node_modules from babel-loader:

exclude: /node_modules/,

You'll need to tweak that if you want to pass modules from node_modules through babel. You might consider explicit includes like this:

// be sure to req path
// var path = require('path')

include: [
  // Include everything from your app path
  path.resolve(__dirname, 'my-app-js-path'),

  // Include gamesystem modules

Post Status

Asked in February 2016
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