fix(css): fix missing source file warning with sass modern api custom importer

[hi-ogawa]

Description

• closes Sourcemap for ... points to missing source files for @import with sass modern api #18111

I added data: to "missing source" false positive list since Sass modern API uses data:... when the code is loaded from custom importer. This would mean css.devSourcemap works only for the initial import of sass files, which is pretty bad, but I couldn't find any solution for this. EDIT: sourceMapUrl works #18113 (comment)

[bolt-new-by-stackblitz]

Run & review this pull request in StackBlitz Codeflow.

[sapphi-red]

https://sass-lang.com/documentation/js-api/interfaces/importerresult/#sourceMapUrl
Returning sourceMapUrl seems to change the sources value.

vite/packages/vite/src/node/plugins/css.ts

Line 2303 in 993d45b

return { contents, syntax }

Could you try to see if it works?

[hi-ogawa]

https://sass-lang.com/documentation/js-api/interfaces/importerresult/#sourceMapUrl
Returning sourceMapUrl seems to change the sources value.

Oops, I totally missed that somehow. This totally works, thanks!

[sapphi-red]

Thank you 👍

[Defite]

Will it be merged into v4?

[sapphi-red]

@Defite I guess you meant v5. It's been released in 5.4.8.

[Defite]

@Defite I guess you meant v5. It's been released in 5.4.8.

Nope, I meant v4, because I can't migrate to v5 right now. I've solved my issue by downgrading sass version to lower one.

[sapphi-red]

We don't have plan to backport this PR to v4 for now.

[Defite]

We don't have plan to backport this PR to v4 for now.

I got it, thanks for answer!

[hi-ogawa]

Nope, I meant v4, because I can't migrate to v5 right now. I've solved my issue by downgrading sass version to lower one.

@Defite Is it possible the warning you're seeing is "legacy js API" one like in #18164? I thought downgrading sass version wouldn't matter for sourcemap warning on modern API, which is what this PR is fixing.

[Defite]

Nope, I meant v4, because I can't migrate to v5 right now. I've solved my issue by downgrading sass version to lower one.

@Defite Is it possible the warning you're seeing is "legacy js API" one like in #18164? I thought downgrading sass version wouldn't matter for sourcemap warning on modern API, which is what this PR is fixing.

Yes, the message is the same as in #18164. But somehow after downgrading sass version I don't see this messages anymore.

[hi-ogawa]

@Defite Okay, so the warning you see is not technically same as this PR. If you follow the link in the warning https://sass-lang.com/documentation/breaking-changes/legacy-js-api, I think you should be able to still upgrade sass and use modern API (though you cannot use css.devSourcemap: true).

[Defite]

@hi-ogawa yep, sorry for bothering in wrong PR.