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Bundlers & Developer Setup

December 2022 Update

Bundlers are one option for serving dev servers & are a wonderful tool for releasing code into production. However, there are now many alternatives that are helpful for speedy local development. Speed comparisons vary depending on what metrics are being used, and like any other framework, there are tradeoffs across any tooling choices.

Vite is currently the leading project for an unbundled development environment. Vite provides a comparison writeup that may be worth checking out when starting a new NodeCG project. The Vue Mastery team also provides a comparison between Vite and Webpack that may be helpful in making your bundling / module choices.

NodeCG usage is currently not limited to any of these options! Make your choice(s) as you will for what you are comfortable with.


Webpack, the most used bundler, has some good documentation for why to use Webpack.

There are several JavaScript bundlers.

  • webpack
    • By far the most used bundler with a lot of community made extensions.
  • rollup
    • Primarily used by libraries like React, Vue - utilizes ES Modules for splitting code
  • parcel
    • Bundler famous for zero-config and super fast building process
  • esbuild

These bundlers allows you to

  • write modular, organised source code
  • treat CSS, images, or any sort of files like JavaScript module
  • use npm packages for front-end (dashboard/graphics)
  • use JSX/TSX, Vue single file component
  • write in other languages like TypeScript
  • and many more

Tutorial: Using Parcel


The below tutorial focuses solely on bundler tooling with NodeCG and was last updated in November 2020; functionality may be limited due to updates in underlying tools, particularly Parcel. If you run into issues, feel free to put in a pull request.

Directory Structure

Basically you will have parcel to output the whole dashboard and graphics directory. Your project would look like this

|- extension
|- schemas
|- src
|- package.json

When you run parcel, it will make dashboard and graphics directory and output bundle result into them.

(After running parcel)

|- extension
|- schemas
|- src
|- package.json
|- dashboard (built)
|- index.html
|- styles.8jx17sx.css
|- main.7x2hdjs.js
|- graphics (built)
|- ds1.html
|- sd1.html
|- styles.03nsh2s.css
|- ds1.rssiahs.js
|- sd1.4jc71nx.js
|- background.d8frsis.png

The random string for each generated files are automatically generated to refresh cache when the files change.


As I said, parcel is (literally) zero-configuration required. It even installs missing packages for you if there is any.

Add parcel to your bundle

npm install --save-dev parcel-bundler
# or
yarn add -D parcel-bundler

The parcel command will be available locally. You can run it either adding npm scripts, or npx parcel/yarn parcel.

npm install -g parcel-bundler
# or
yarn global add parcel-bundler

With this, parcel command should be available globally. Just run parcel to run the bundler.

Make an entrypoint

When building front-end, HTML file is usually used as entrypoint. You can just use your HTML file with your scripts and stylesheets imported.

<!DOCTYPE html>
<meta charset="utf-8" />
<link rel="stylesheet" href="./styles.css">
<div id="tech"></div>
<!-- Or a lot of pre-defined elements -->
<script src="./index.js"></script>

The entrypoint HTML file will also be compiled in the bundler. So you can have many kind of files in the script tag. Parcel will automatically detect file format and use an appropriate library/compiler to bundle the file.

<script src="./"></script>
<script src="./app.tsx"></script>

Or the entrypoint doesn't even have to be an HTML file. For example, you can use Pug to have common parts of HTML file into one file.

doctype html
title graphics-ds
include lib/common.pug

Run the command

For development, with file change detection and hot-reloading:

parcel watch src/dashboard/index.html --out-dir dashboard --public-url ./

For production build, with optimized output:

parcel build src/dashboard/index.html --out-dir dashboard --public-url ./

(Replace src/dashboard/index.html with your entrypoint files.)

You can use a glob pattern to use multiple entrypoints, if you have multiple pages to compile

parcel build src/dashboard/*.html --out-dir dashboard --public-url ./

A detailed reference can be found in the Parcel CLI reference documentation.

Even though it already works for most cases (!), a bit of configuration might be recommended/required.


Parcel uses babel out of box, and the default supported browsers are >0.25% which includes old browsers like IE.

Considering how NodeCG is used, it's the best to target only modern browsers or just Chrome. To do so, add browserslist property to package.json.

For example,

// ...
"browserslist": "last 2 chrome versions",
"nodecg": //...

Refer to this page for detailed browserslist syntax.

Going further

Due to the huge amount of features parcel offers out of box, at this point you already have a lot more options for your front-end development. For example:

  • React development with JSX/TSX
  • Vue single file component
  • TypeScript or other alternative languages

Also, if your project becomes too advanced for parcel to handle, you can switch to webpack - there are tools that can do this configuration conversion, to either Webpack or other tools like Vite, WMR, or Turbopack.