feat: add css key to vite config

[jacobhq]

Checklist

• I have read Contributing > Pull requests

Related issue

Fixes #504

Overview

Add CSS key to vite config.

[Valerioageno]

@jacobhq does this PR fix the bug you linked on your local setup?

[jacobhq]

@jacobhq does this PR fix the bug you linked on your local setup?

To use the solution:

import type { TuonoConfig } from "tuono/config";

const config: TuonoConfig = {
  vite: {
    css: {
      preprocessorOptions: {
        sass: {
          api: 'modern-compiler', // or "modern"
        },
      },
    },
  }
};

export default config;

We need to upgrade vite to at least 5.4. I think we should upgrade vite straight to v6, which will fix #504, and not require the user to make config changes.

This PR is still valid and useful, but it won't fix #504 unless we upgrade vite in this PR. How should I proceed?

[Valerioageno]

Why do we need to update vite here?
I think we should just add the key in the normalizeConfig function.

The goal is to deliver quality on the first iteration (when the fix is small/medium size) for multiple reasons:

1. We don't risk to release partial fixes
2. We review only ready and meaningful PR without wasting time
3. We keep a better tracking with the issue system

Please make this PR draft and ask for review when the whole bug fix is addressed. If you need help we can sync on Discord

[jacobhq]

Why do we need to update vite here?

Current version of vite in tuono does not support the api: 'modern-compiler', as per Sass docs, so the issue won't be fixed unless we take one of the paths I mentioned above. I suggested upgrading to vite 6 or above because it uses modern-compiler by default, and we will eventually need to do this upgrade anyway.

I think we should just add the key in the normalizeConfig function.

Sorry, I didn't realise we had this config build step. I will update it, which will add CSS config support, however even after this, the issue won't be fixed unless we upgrade vite.

Again, sorry about the early review.

[Valerioageno]

I see two task to fix this issue:

• update the normalizeConfig function + update the tests
• Bump vite to "vite": "^5.4"

[marcalexiei]

I left a few comments.

I also performed a quick test on `examples/tuono-app` and it seems to be working

[marcalexiei]

Next time, could you please follow the contributing guidelines and procedures?

https://tuono.dev/documentation/contributing/pull-requests#overview

Please don't:
Do not use force push after marking the PR ready for review.
Reasoning: GitHub cannot track changes across force pushes, which slows down our ability to perform incremental reviews.

---

https://tuono.dev/documentation/contributing/pull-requests#addressing-review-feedback

After addressing all feedback, whether through code changes or by starting a follow-up discussion, please re-request a review from each maintainer whose feedback you've addressed.

Thanks

---

I left one comment regarding the documentation text for the option.

[jacobhq]

Yep, thanks. In future I will merge instead of rebase, so no more force pushes.

[marcalexiei]

Thanks, looks good to me.