fix(plugin-vue): suppress spammy lightningcss warnings with new tag

[matthewwithanm]

Description

Discussed previously in both #507 and #594, lightningcss has some noisy warnings about (apparently) expected invalid CSS.

After upgrading to Vite 8, I'm seeing them again with a slight variation: the message now starts with "[lightningcss minify]" instead of just "[lightningcss]", so the existing RegExp no longer matches.

I'm not clear on why the invalid selectors are included in the first place, but when I reverted to Vite 7 they were there too so I guess this is expected behavior?

Apologies in advance if I'm missing something!

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vitejs/plugin-vue@753

npm i https://pkg.pr.new/@vitejs/plugin-vue-jsx@753

commit: 31fdb00

[sapphi-red]

I would expect the vue specific selectors (:deep, :slotted, :global) to be transformed before the CSS is minified. Would you be able to provide a reproduction?

[matthewwithanm]

@sapphi-red Thanks for the reply! Yeah, that's I expected but I was thrown by the fact that the selectors were present in the Vite 7 output and assumed I didn't understand the expected behavior. 😅

This was the result of using an scss mixin that contains :deep inside of a :deep selector. The mixin in question was intended (as I understand it) to be usable inside both normal selectors and :deep, so it included both and relied on the redundant one having no effect. Vite 7 was letting it through silently (producing invalid CSS), whereas after the upgrade, lightningcss produced this warning.

Going to close this PR.