Runes in non-Svelte files failing on runes not defined

[egilsster]

Trying out Svelte 5 on a fairly sized project and got blocked by this problem. I am migrating a writable store to a little API wrapping some state with the $state rune, however, if I define the object in a thing.svelte.ts file the app crashes on an error stating that $state is not defined. I suspect this has something to do with how webpack bundles these files together with different, since the same store works fine when defined within a regular Svelte file.

I am using swc to build ts and js files and the latest svelte compiler to build the svelte files. I've put up a minimal reproduction project here https://github.com/egilsster/runes-repro

It's my best guess that the problem lies within svelte-loader.

[non25]

Have you tried to add svelte-loader for svelte.js files also so it runs the compiler? I don't think anything else except svelte compiler understands that magic. 😁