Lightningcss does not resolve url() inside an astro scoped style

[jpcano]

Astro Info

Astro                    v4.8.4
Node                     v18.18.0
System                   Linux (x64)
Package Manager          unknown
Output                   static
Adapter                  none
Integrations             none

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

I am using the CSS attribute background-image: url('path_to_image'); in a div inside an Astro's scoped style.
lightningcss resolves the URL of the image pointing to an inexistent file in the server (ie, "/Z1Mtyq" in the reproducible example I attached) and therefore the background image is not displayed.

If I use it in a global style, the URL of the image is resolved correctly and works as expected.

What's the expected result?

I expect lightningcss to resolve the URL in a scoped style like Astro does when I am not using lightningcss

Link to Minimal Reproducible Example

https://stackblitz.com/edit/withastro-astro-5pmcku?file=src%2Fpages%2Findex.astro

Participation

• I am willing to submit a pull request for this issue.

[matthewp]

@bluwy I believe that LightningCSS does not resolve relative to the current file but rather from the root and that's the limitation being seen here. Is that correct?

https://github.com/withastro/astro/blob/464b0a108ecd0b77e6e34829381ccd1335d525ce/packages/astro/src/core/compile/style.ts#L27C25-L27C38

[bluwy]

It's a bug in Vite while preprocessing the CSS. The urls should be left intact and not be resolved while preprocessing. But it will be resolved later by Vite in a separate pipeline. I submitted a fix upstream.

[jpcano]

@bluwy Thank you for submitting the patch. Do you know if there is any way to make url() work with the latest Astro version without waiting for your patch to be merged?

[jpcano]

I answer myself: One option is to move all the url() statements from the scoped styles to the global stylesheet as I showed in a comment on my stackblitz example.

[bluwy]

You can also patch Vite with the fix I made to make it work at the meantime, as after the fix is merged upstream, it would go into Vite's 4.3 beta, so you may have to wait longer (unless you're also ok with using beta). At the moment, there's not much Astro can do itself.