Creating an NPM package using Bun

[pinkboid]

I want to create a JavaScript library to publish on NPM, but develop it using Bun for runtime testing and dependency management. Is there any official documentation on how to do it? I assume it's exactly the same as you would create an NPM package normally, except you .npmignore all the bun stuff. Any other steps I should take?

[pinkboid]

For example, what am I to do about bun.lockb? I assume I simply add it it to .npmignore, but would like clarification.

[idleberg]

Lock files are not part of a package tarball, it is not relevant what you use in your repository. For the same reason the React team (to pick a popular example) can work with a Yarn lock file.

[bzvestey]

I am also interested in this. I am looking into converting a set of micro-services over to using bun instead of node, and would also like to use it as much as possible for a library of shared code for them. Do I use bun for everything but the npm publish command? Or is there a way to publish from bun?

[moshOntong-IT]

Do you found a solution?

[testerez]

May be a starting point: https://github.com/wobsoriano/bun-lib-starter (found here: https://github.com/oven-sh/awesome-bun#boilerplates)

[Alexnortung]

Thanks bun-lib-starter is a great starting point

[arshad-yaseen]

https://bunup.dev/

[ramdanegie]

Yes, you can absolutely use Bun to develop and publish npm packages. Here's the full workflow:

1. Initialize

bun init

This creates package.json, index.ts, and .gitignore.

2. Structure

my-package/
├── src/
│   └── index.ts
├── package.json
├── tsconfig.json
└── bun.lockb

3. Build for npm

bun build ./src/index.ts --outdir ./dist --target node

For TypeScript declarations, add a postbuild script:

{
  "scripts": {
    "build": "bun build ./src/index.ts --outdir ./dist --target node",
    "postbuild": "tsc --emitDeclarationOnly --outDir dist"
  }
}

4. package.json fields

{
  "name": "@yourscope/my-package",
  "version": "0.1.0",
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "files": ["dist"],
  "scripts": {
    "build": "bun build ./src/index.ts --outdir ./dist --target node",
    "prepublishOnly": "bun run build"
  }
}

5. About bun.lockb

No action needed. npm automatically ignores lockfiles when packing the tarball.

6. Publish

bun publish  # Bun 1.1+
# or
bunx npm publish

Your users can install with npm install, yarn add, pnpm add, or bun add.

7. Alternative: bunup.dev wraps bun build with declarations, ESM/CJS dual output, and minification.

[hesprs]

By the way, how can I use bun to pack a package into a tarball like npm pack?

---

I know it now, it's bun pm pack.