A demo app showcasing the use of real JavaScript modules in production—complete with cross-browser fallbacks for legacy browsers.

The techniques used in this demo are described in the article Using Native JavaScript Modules in Production Today.

🚀  View the demo on Glitch  👉

To show that this technique can work for most types of applications, this demo is a React app and includes advanced features like:

• Babel transforms (including JSX)
• CommonJS dependencies (e.g. react, react-dom)
• CSS dependencies
• Asset hashing
• Code splitting
• Dynamic import (w/ polyfill fallback)
• module/nomodule fallback

To see how all these features are configured, view the Rollup config file (rollup.config.js). To see the generated output, view the public directory after building the app (see below).

To run the app locally, clone this repo and npm install all dependencies, then run the following command:

npm start

This will start a local server at http://localhost:3000, where you can view the app.

If you want to run the app and have Rollup monitor the code for changes (and rebundle), you can run:

npm run watch

To build the app without starting the development server, run:

npm run build

By default the app is started in development mode, which means the bundle output is unminified, and a nomodule bundle is not generated. You can change this by prefixing any of the above commands with NODE_ENV=production, for example:

NODE_ENV=production npm start