Using Bun.sh to create a Typescript library

If you remember, there was a project called tsdx that offered a great developer experience. This project had everything included — ESlint, Typescript support, and testing. Bun.sh definitely took some pointers from this project and offers a good dev experience with alot of support baked into the runtime itself. This article will go over some of the positives that Bun.sh offers when creating a Typescript library.

Bun supports Typescript out-of-the-box

This is something that helps immensely. No need to wrangle a tsconfig file. All you need to do is type bun init and you have the bare bones of a Typescript project.

Bun has testing built-in

No need to figure out what testing library you will need. Bun comes with a testing library that is comptabile with the Jest testing API. If you haven’t used Jest, I do recommened it highly. With Bun, just run bun test. Make sure that you have test files properly named and they will be picked up by the test runner.

Bun has support for other JS runtimes

Bun markets itself as a drop-in replacement for npm and suggest that this is the easiest way to ease the use of Bun in your workflow. By running bun add you can download packages from npm. If you want to download packages from JSR, you can do so by running bun add jsr <package name>. You can also configure the installer to point at git repos or private npm registries as well.

Publishing

Publishing is pretty straight-forward. You can publish to npm by running bun publish.

Conclusion

I would highly recommend using Bun for library development. With Bun, you have a tool that can do it all — install other dependencies, test, and publish. If you have a project that uses Node, I would highly recommend. There would be some work converting the existing tests (you do have tests, right?) into a format that is compatable with Bun, but it is well worth the effort when you look at everything that you get in return.