🐛 BUG: vite.build.sourcemap does not generate sourcemaps for client-side components on build

[Tc-001]

What version of astro are you using?

1.0.0-beta.72

Are you using an SSR adapter? If so, which one?

none

What package manager are you using?

pnpm

What operating system are you using?

Linux

Describe the Bug

Sourcemaps are useful for debugging components while developing an application. But there are also tools (Ex. Sentry), that can use the sourcemaps in production to get a similar experience with in-the-wild bugs.

This functionality is currently unavailable however, as astro fails to generate soucemaps on build

The bug

1. Clone and set up https://github.com/withastro/astro/tree/latest/examples/framework-svelte
2. Set vite.build.sourcemap in astro.config.mjs to true
3. Build the site

Expected: A sourcemap file (*.js.map) for each client-side script in ./dist, as well as the script itself referencing the sourcemap as per vite

Actual: an almost empty entry.mjs.map with no modifications to other files

{"version":3,"file":"entry.mjs","sources":[],"sourcesContent":[],"names":[],"mappings":";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;"}

This was also in the build logs:

Sourcemap is likely to be incorrect: a plugin (astro:build) was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help
Sourcemap is likely to be incorrect: a plugin (astro:vite-plugin-env) was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help
...

Link to Minimal Reproducible Example

https://github.com/withastro/astro/tree/latest/examples/framework-svelte

Participation

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

[Tc-001]

On a closer look there do seem to be some sourcemaps in ./dist/chunks, but they have the same issue as entry (they are almost completely blank) and are not referenced anywhere as far as I can see

(also maybe only for markdown pages? Unsure)

[natemoo-re]

Ooh very strange! Thanks for opening an issue, I know digging into sourcemaps is definitely on our list.

This would be great to fix.

[pikeas]

Happening in dev as well in 1.0rc3:

[serve]    404 /@id/@astrojs/vue/@astrojs_vue_client__js.js.map

[matthewp]

@natemoo-re I'm going to hand this one over to @bluwy.

[bluwy]

Gimme

[matthewp]

This would be a good one to create a test for.

[pikeas]

Still happening with 1.0.0.

$ npm run dev

> project@0.0.1 dev
> astro dev

  🚀  astro  v1.0.0 started in 59ms

  ┃ Local    http://localhost:3000/
  ┃ Network  use --host to expose

03:21:13 PM [serve]    404 /@id/astro/runtime/client/astro_runtime_client_hmr__js.js.map
03:21:13 PM [serve]    404 /@id/@astrojs/vue/@astrojs_vue_client__js.js.map

[bluwy]

@pikeas I believe that's related to #4219 in dev mode.