Skeleton v2 migration to Svelte 5

[endigo9740]

Svelte 5 has reached Release Candidate status per today's Svelte Summit:

• https://www.youtube.com/watch?v=gkJ09joGBZ4
• Does Skeleton v2.x Support... #2400

The Plan

As such, we will begin investigating the migration process for Skeleton v2 projects. This will start with a research phase will will start asap.

For Users

If you use Skeleton v2 and are keen to update to the Svelte 5 RC, we encourage you do so on a dedicate feature branch. We match Svelte's stance on this and DO NOT recommend you deploy to Production yet. If you encourage issues while doing this, please report them in the comments section below.

For Contributors

Likewise, please post any findings while testing the migration process here. This will be helpful in generating a dedicated Skeleton + Svelte 5 migration guide asap. Note that we will not be enabling Svelte 5 features in Skeleton v2. These should be restricted to Skeleton v3.

[endigo9740]

I'm happy to report that migrating from Svelte v4 -> Svelte v5 RC seems to cause no major breaking changes in small scale projects running Skeleton v2. This includes the following:

• A fresh Skeleton CLI generated project
• Migrating a minimal application (migrated: https://www.skeletonlabs.co/)

Note the only notable issues is the addition of new a11y warnings, which we'll aim to address before the next release next week:

• Resolve a11y warnings in multiple components #2632

Next up:

• Upgrading the Skeleton v2 doc site

Note that we will not be pushing Svelte v5 RC updates to production. This will isolate to a test branch only.

I'll write a follow up post once the v2 doc site update test is complete, then set about writing the migration guide to share with everyone immediately after. ETA should be late today or tomorrow.

[endigo9740]

I ran into a couple snags while preparing to update the Skeleton v2 doc site - we need to upgrade to Svelte v4 and SvelteKit v2 first.

• See: v2 Docs: Migrate the v2 docs to Svelte 4 and SvelteKit v2 #2637

So I'll pick up from here tomorrow and verify all is well for Svelte v5 RC. Then the migration guide will start immediately after!

[endigo9740]

The guide is now available here! Find it pinned in the GitHub Discussions section:

• Skeleton v2 + Svelte v5 RC Migration Guide #2640