Svelte 5 compatibility

[techniq]

Issue to track any Svelte 5 compatibility issues. Hoping close to 0 changes are required in Svelte UX to support 5.

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FIXED: can only receive attributes, not directives

issue: sveltejs/svelte#10382
fix: sveltejs/svelte#10391

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FIXED: type attribute must be a static text value if input uses two-way binding

Fixed via: sveltejs/svelte#9713
Reported in discord. If ran within the Svelte 5 beta (ex. 5.0.0-next.15), currently Input throws a 'type' attribute must be a static text value if input uses two-way binding error

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FIXED: let directive on <svelte:self>

issue: sveltejs/svelte#9710
fix: sveltejs/svelte#9727

[CropWatchDevelopment]

I found a fix for this, I made a PR #145.
There is one more problem with TreeList.svelte, but I am hoping to get early feedback on this fix first!

[techniq]

Thanks @CropWatchDevelopment, but it looks like this is a regression with the Svelte 5 compiler (see issue and Twitter/X discussion, including confirmation by Simon (Svelte/Vercel team).

I also found a workaround using <svelte:element>, although I would prefer to wait for it to be fixed upstream (which it should be). It looks like Svelte 3/4 had an explicit check for bind:this that likely was overlooked as part of the Svelte 5 rewrite, so likely the fix will be similar (and hopefully as simple).

Would it be OK if we wait a bit to see if this is resolved upstream before we consider a workaround?

I'm curious what you found in TreeList.

[CropWatchDevelopment]

100% Yes OK to wait until later. After checking the Svelte repo and seeing all of the v5 issues logged. I am thinking I may wait a few months even before making the move. It seems like v5 may take a bit be fully worked out :) I will pull down the PR, but Hope to help out in the future!

[techniq]

100% Yes OK to wait until later. After checking the Svelte repo and seeing all of the v5 issues logged. I am thinking I may wait a few months even before making the move. It seems like v5 may take a bit be fully worked out :) I will pull down the PR, but Hope to help out in the future!

FWIW, the bind:this issue is already fixed and should be on 5.0.0-next.16 once released (already on the preview REPL). I was going to test my StackBlitz until I realize .16 wasn't published yet.

TBH, that's my plan ATM. As much as I love all the great things coming in Svelte 5, I personally will wait closer to the official release before I focus too much on it. My plan is for Svelte UX (and LayerChart) 1.0 releases to be fully compatibility with Svelte 3/4/5, and 2.0 I'll probably start embracing some of the Svelte 5 features (runes, snippets, etc) which will likely break 3/4 compatibility, but as long as 5 is a drop in replacement for 3/4, I think that's a fair tradeoff.

Just the speed/size improvements in 5 running non-rune mode is exciting.

Thanks for the PR and discussion.

[dimfeld]

Filed sveltejs/svelte#10382 because SelectField.svelte fails to compile with latest Svelte 5.

[techniq]

Thanks @dimfeld for submitting the upstream issue with repo. I've updated this issue's description to make it easy to track any known Svelte 5 compatibility issues. The Svelte team has been amazingly fast resolving these thus far.

[dimfeld]

Haven't tried it but I think this will hit svelte-ux as well sveltejs/svelte#10395

edit: this one is fixed now