[astro-purgecss] CSS files not found in SSR mode as of v4.6.0

[mef]

A regression in v4.6.0 causes CSS files to 404 in the build for pages rendered in Astro's SSR mode.

The feature was working well in v4.5.0 and earlier version.

Side-note: this is a follow-up of a discussion started inside #660.

To Reproduce

1. Create an astro project with page(s) rendered in SSR mode (output server or hybrid in Astro config), and some CSS somewhere.
2. Run npm run build
3. Run npm run preview

Expected behavior

All pages load with their CSS style correctly applied.

Observed behavior

The SSR-generated pages load with no style at all. The developer console shows error messages with CSS files not found (404).

Static pages have CSS applied as suitable.

Additional context

As of v4.5.0, astro-purgecss renames CSS files, and updates their references inside the pages consuming them.

Cause of the regression has been identified:

• In v4.5.0, the files in which to update the .css file names were identified by iterating through all files of the output directory. As a consequence, in addition to static HTML files, SSR modules like dist/server/manifest_[hash].mjs were also updated with reference to the renamed files.
• In v4.6.0, only the files in the routes variable of the Astro plugin hook are processed - hence only the paths corresponding to static HTML files.

@the-dijkstra which approach would you like to take to fix this one?

[the-dijkstra]

Hey @mef thank you so much for this well detailed issue.

What if we add the extra step to update the manifest file ? I think this will solve the problem

maybe also worth exploring iterating through pages instead of routes https://github.com/codiume/orbit/issues/654#issuecomment-2379835208