Migrate to lightningcss?

[NullVoxPopuli]

Is rust, so it's 100x faster: https://lightningcss.dev/

These are the relevant docs for transformation: https://lightningcss.dev/transforms.html#visitors

It has sourcemap support

[gossi]

I recently dropped any other preprocessors (postcss) to be fully on lightningcss on all my tools, I can totally support this.

For theemo I gave options for people to configure their lightningcss (or even deactivate this at all): https://theemo.io/api/@theemo/build/interfaces/BuildConfig#lightningcss

I followed the idea from vite here, where they provide [tool]Options config settings. They support multiple tools, and allow for end-users to configure them to their liking.

I see the same here: Make lightningcss the default and make it configurable.

At the same time you can allow for more preprocessors (postCSS, SASS, etc.). That makes them allowed to be run, and configured, but they are not the default. That also allows extending support for preprocessors based on an identification: eg file extensions (.scss) or other identifiers <style type="sass">

[NullVoxPopuli]

The transforms we have to do are very css ast specific, and I don't think multiple could be supported simultaneously without re-implementing the css transform logic in each.

So: Doable, but some duplication needed

[NullVoxPopuli]

I think that approach is growing on me though

this library can "implement the same transform for each processor", keyed off of type

and then the rollup/vite plugin will need to receive options / plugins for each preprocessor.

the existing code can be type="postcss" -- and then expose a postcss plugins config.

and lightningcss can be the default (non-breaking, because it's already not configurable -- and I don't want the default "vanilla CSS" to be configurable anyway)