svelte@5.43.9

sveltejs/sveltesvelte@5.43.9Nov 17, 2025by github-actions[bot]

AI Summary

A release focused on stabilizing async rendering, derived state reactivity, and effect trees, addressing blockers and async hydration.

Key Highlights

Fixes for async blockers and deriveds
Fix for async `@const` hydration
Ensure eager effects don't break reactions

Full Release Notes

### Patch Changes

-   fix: correctly handle functions when determining async blockers ([#17137](https://github.com/sveltejs/svelte/pull/17137))

-   fix: keep deriveds reactive after their original parent effect was destroyed ([#17171](https://github.com/sveltejs/svelte/pull/17171))

-   fix: ensure eager effects don't break reactions chain ([#17138](https://github.com/sveltejs/svelte/pull/17138))

-   fix: ensure async `@const` in boundary hydrates correctly ([#17165](https://github.com/sveltejs/svelte/pull/17165))

-   fix: take blockers into account when creating `#await` blocks ([#17137](https://github.com/sveltejs/svelte/pull/17137))

-   fix: parallelize async `@const`s in the template ([#17165](https://github.com/sveltejs/svelte/pull/17165))