webpack + nodecg

extension -> index.js

const express = require('express');
const app = express();

const {NODE_ENV} = process.env;

module.exports = function(nodecg) {
  if (NODE_ENV !== 'production') {
    const webpack = require('webpack');
    const webpackConfig = require('../webpack.dev.config');
    const devMiddleware = require('webpack-dev-middleware');

    const compiler = devMiddleware(webpack(webpackConfig), {
      publicPath: webpackConfig.output.publicPath,
      stats: {colors: true},
      log: nodecg.log
    });

    app.use(compiler);
  }

  nodecg.mount(app);
};

graphics -> index.html

...
<script src="graphic.min.js"></script>
...

package.json

...
  "scripts": {
    "build": "webpack --progress -p"
  }
...

webpack.dev.config.js

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

module.exports = {
  context: path.join(__dirname, 'graphics'), // This...
  devtool: "inline-sourcemap",
  entry: './js/index.js',
  output: {
    path: path.join(__dirname, 'graphics'), // this...
    publicPath: '/graphics/tagg-stack/',    // and this are the important lines
    filename: 'graphic.min.js'
  },
  plugins: [
    new webpack.NoEmitOnErrorsPlugin()
  ]
};