`browser` check for dynamic server module throws error whilst building.

[LumiFae]

Describe the bug

I have a class that helps me manage specific database items, and this class dynamically imports from either the client side database stuff, or server-side (like administration level database stuff). This totally works fine in npm run dev but when it comes to npm run build, the code doesn't build and throws an error, even though it's behind a browser check and none of the server side stuff is saved, only passed on.

Reproduction

Make functions that dynamically import server side modules or client side modules depending on the browser check and then run that function both on the server and the client.

Logs

[vite-plugin-sveltekit-compile] [vite-plugin-sveltekit-guard] Cannot import $lib/server/firebase.ts into client-side code:
- src/routes/[companyId=firestoreid]/+page.svelte imports
,  - $lib/classes/items/certification.ts imports
,    - $lib/classes/items/item.svelte.ts dynamically imports
   - $lib/server/firebase.ts
[vite-plugin-sveltekit-guard] Cannot import $lib/server/firebase.ts into client-side code:
- src/routes/[companyId=firestoreid]/+page.svelte imports
,  - $lib/classes/items/certification.ts imports
,    - $lib/classes/items/item.svelte.ts dynamically imports
   - $lib/server/firebase.ts
    at follow (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:65:10)
    at follow (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:76:5)
    at follow (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:72:5)
    at follow (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:72:5)
    at follow (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:72:5)
    at Object.check (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/graph_analysis/index.js:84:4)
    at file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/index.js:575:12
    at Array.forEach (<anonymous>)
    at Object.handler (file:///Users/x/Developer/x/app/node_modules/@sveltejs/kit/src/exports/vite/index.js:570:25)
    at file:///Users/x/Developer/x/app/node_modules/rollup/dist/es/shared/node-entry.js:20812:40

System Info

System:
    OS: macOS 15.5
    CPU: (11) arm64 Apple M3 Pro
    Memory: 106.14 MB / 18.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.13.1 - /usr/local/bin/node
    npm: 10.5.2 - /usr/local/bin/npm
  Browsers:
    Edge: 138.0.3351.83
    Safari: 18.5
  npmPackages:
    @sveltejs/adapter-vercel: ^5.6.2 => 5.6.3 
    @sveltejs/kit: ^2.17.2 => 2.19.1 
    @sveltejs/vite-plugin-svelte: ^4.0.0 => 4.0.4 
    svelte: ^5.28.2 => 5.28.2 
    vite: ^5.4.18 => 5.4.18

Severity

annoyance

Additional Information

No response

[dummdidumm]

The error says that you are importing a server-only module into a file that can run on the client. That is disallowed. The browser check is never reached. If this should be called on both the server and the client you cannot have that code in server only modules (i.e. xxxx.server.ts files or files inside src/lib/server.

Edit: I misread, it's about the dynamic import happening afterwards (a minimum reproducible would really have helped avoid this confusion)

[LumiFae]

Edit: I misread, it's about the dynamic import happening afterwards (a minimum reproducible would really have helped avoid this confusion)

Yes sorry, that's my bad, I thought the image above would give some insight on the issue. Thanks for re-reading though! I'll try avoid stuff like this in future