Reduce sub-sub-sub dependencies

[pi0]

Context: from es-tooling/module-replacements#60 (comment) by @AbhiPrasad

Currently unbuilds install lots of sub-dependencies some are not required for basic builds. (graph)

From CSS stuff, I assume they are related to mkdist optional loaders and I think we can replace them with optional peer dependencies (as part of #381 migration) and even a simple smart prompt to install if needed.

Rollup and its plugins are also a pain point. While inlining them all is one option, perhaps we can wait for rolldown to be mature and swap to it in v4.

[drwpow]

perhaps we can wait for rolldown to be mature and swap to it in v4

As someone that’s been following the Rolldown project somewhat-closely, it seems to be in a good place right now for JS/TS, but still has a few rough edges around other filetypes like CSS (e.g. importing in a React library).

All that said, I’m not sure how wide the scope of different project types unbuild wants to tackle. If unbuild is centered on JS/TS then Rolldown seems like it’s at a point where it could be explored as a replacement (as a beta). But if unbuild wants to give equal support to usecases like React libraries with CSS, libraries that ship WASM, and other extended filetypes, then Rolldown’s plugin ecosystem will probably have to mature quite a bit futher (I believe they’re currently still shipping breaking plugin API changes).

Note: worth noting that Rolldown does have much better support for CSS and a few other things with no plugins needed! But the API is also not stable so IMO not ready to build upon just yet.