fix!: default build.cssMinify to 'esbuild' for SSR

[sapphi-red]

Description

Even for SSR, there's no reason to skip minify for CSS files.

SvelteKit and Astro sets this.
https://github.com/sveltejs/kit/blob/6200a48befe538176b1f5c1cb9e32c51af84345b/packages/kit/src/exports/vite/index.js#L607
https://github.com/withastro/astro/blob/7e1db8b4ce2da9e044ea0393e533c6db2561ac90/packages/astro/src/core/build/static-build.ts#L178-L180

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines, especially the Pull Request Guidelines.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Update the corresponding documentation if needed.
• Ideally, include relevant tests that fail without this PR but pass with it.

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[patak-dev]

@sapphi-red you marked this as a breaking change, would we still be able to merge it for Vite 5.1? Vite 6 is too far away right now.

[patak-dev]

Ah, ok, I see:

• docs: build.minify defaults to false for SSR #15636

I think we could still merge this one in Vite 5.1, but maybe I'm missing something here.

[sapphi-red]

I think the change has a slightly big impact. Given that there's a workaround, I think it's better to wait for Vite 6.

[bluwy]

Should we also only minify only if ssrEmitAssets is true? Otherwise the minified result is thrown away.

[sapphi-red]

Should we also only minify only if ssrEmitAssets is true? Otherwise the minified result is thrown away.

Even if ssrEmitAssets is false, the user wants the same file hash for CSS files (also for other assets). To get the same file name between client and server, the same content needs to be generated. So I think we need to enable minify.

[bluwy]

I don't quite understand how one would compare the same file name between client and server if ssrEmitAssets is false? There won't be any assets in the first place. And the JS generated by client and server builds would already be different.

[bluwy]

Ah I guess checking the Remix issue, it's because the hash is exposed for .css?url 🤔

[sapphi-red]

Yep, the the hash is exposed for .css?url. The URL on the server points to nothing.
Example: https://stackblitz.com/edit/vitejs-vite-8zxxdh?file=main.js

[sapphi-red]

I'm using raw.ssr to align with minify: raw.ssr ? false : 'esbuild', above. Do we want to update that to consumer === 'server'? I guess we don't want to, because we would want to enable minify for edge runtimes.