Svelte 5 reactive classes behave inconsistently

[SenneVanderAuwera]

When using a $state() property in a class, the library has some inconsistencies. It seems that while dragging the object is not correctly copied, only when dropped. This causes the element to not be rendered correctly in the container.

I have provided a REPL where you can see the weird behaviour. If the id property is changed to a $state() variable it breaks the functionality entirely.

[isaacHagoel]

I can't look at the REPL right now but is it the same as #640 (a bug was submitted in the Svelte repo)?

[SenneVanderAuwera]

I think they are definitely related but i feel my issue has nothing to do with svelte:element as i'm not using it.

[fhirter]

+1 on this, I am not using svelte:element and my app breaks when I use $state() on the dragable list.

[isaacHagoel]

I need a minimal reprod REPL to look into.

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On Fri, May 23, 2025, 21:27 Fabian Hirter ***@***.***> wrote: *fhirter* left a comment (isaacHagoel/svelte-dnd-action#644) <#644 (comment)> +1 on this, I am not using svelte:element and my app breaks when I use $state() on the dragable list. — Reply to this email directly, view it on GitHub <#644 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE4OZC4G3B7BAXRXHKKNKMT274AZVAVCNFSM6AAAAAB3CRYISWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSMBUGEZDEOBRGI> . You are receiving this because you commented.Message ID: ***@***.***>

[SenneVanderAuwera]

I've updated my previous REPL. I hope this way it's a bit clearer.

[pierre-H]

@isaacHagoel : any news ?

[isaacHagoel]

@pierre-H I didn't spend much time on this because:

1. There is a reported Svelte 5 bug that seems to be at the root of this
2. there's a workaround so this is not blocking anyone (please correct me if i'm wrong)