Tsdown – The Elegant Bundler for Libraries

16 pointsposted 6 hours ago
by jcbhmr
(tsdown.dev)

5 Comments

frankdejonge

2 hours ago

I’m using tsdown for a collection of packages and am switching a current project (https://flystorage.dev)over to it. I use it in “unbundle” mode, which doesn’t bundle but does file for file transpilation. To me, it’s an opinionated rolldown configuration with a simplified API. You can script up in a couple of lines of code which packages in a monorepo to compile and what formats to compile for. An example of that can be found here: https://github.com/duna-oss/deltic/blob/main/tsdown.config.t...

Compared to using plain tsc to compile the code, is that it’s a lot quicker. The compiled code has some odd conventions, like using void 0 instead of undefined, but … whatever works!

So far, it has been an easy-entry high-ROI tool that helps me publish TS/JS tools quite easily.

MrJohz

an hour ago

I want to move a project I work in over from tsc to tsdown this week at some point, also with the unbundled mode.

Currently we're using tsc with the new build mode to build everything at once, but the result is incredibly brittle and requires a lot of unnecessary extra configuration all over the place that tends to confuse people when they need to add extra packages or make changes somewhere. It's also very slow (hopefully something that will be fixed by tsgo, eventually).

My initial plan was to have a separate tsdown config in each package and use pnpm to build the entire monorepo (or at least, the parts necessary for each sub-application) in parallel. But your config also looks like a useful approach, I'll explore that as well. Thanks for sharing!

JimDabell

3 hours ago

The website doesn’t tell me why I would use this instead of just Rolldown.

The “What is tsdown” link goes to a video with pre-roll ads.

I put the video URL into Gemini and asked it what it does. Gemini hallucinated a comparison with Rspack.

I followed the link to documentation from the YouTube description and it took me back to the main page that does not have a description of what it does.

There is an FAQ with a single question:

> Will tsdown support stub mode (similar to unbuild)?

Is there any kind of text description available for what this is and why I – as somebody who is currently writing a lot of front-end code – should care?

typpilol

2 hours ago

Afaict, it seems like a rust build on top of oxc and roll down?

But again, all it says is it's fast. And vite is pretty damn fast and widely supported so?

Plus vite exposes roll down config options so yea, what's the point?

frankdejonge

2 hours ago

I use it to compile backend code. For those use-cases, IMO, vite itself is not so interesting (although I do use vitest). Using tsdown gives me a simplified API to compile my BE code so I can publish it to NPM. Nothing more nothing less. It’s faster and less work to orchestrate using TSC for CJS and ESM output, so very high ROI for me.