svelte@5.53.7

sveltejs/sveltesvelte@5.53.7Mar 3, 2026by github-actions[bot]

AI Summary

This patch release addresses compiler and runtime performance issues, including optimizing CSS selector pruning and name scanning, while fixing edge cases in error handling and component rendering.

Key Highlights

Fix `__svelte_meta` generation in else-if chains
Optimize CSS selector pruning
Avoid O(n²) name scanning in scope generation
Preserve boundary errors with keyed rows during async updates
Cache element interactivity in the compiler

Full Release Notes

### Patch Changes

-   fix: correctly add \_\_svelte_meta after else-if chains ([#17830](https://github.com/sveltejs/svelte/pull/17830))

-   perf: cache element interactivity and source line splitting in compiler ([#17839](https://github.com/sveltejs/svelte/pull/17839))

-   chore: avoid rescheduling effects during branch commit ([#17837](https://github.com/sveltejs/svelte/pull/17837))

-   perf: optimize CSS selector pruning ([#17846](https://github.com/sveltejs/svelte/pull/17846))

-   fix: preserve original boundary errors when keyed each rows are removed during async updates ([#17843](https://github.com/sveltejs/svelte/pull/17843))

-   perf: avoid O(n²) name scanning in scope `generate` and `unique` ([#17844](https://github.com/sveltejs/svelte/pull/17844))

-   fix: preserve each items that are needed by pending batches ([#17819](https://github.com/sveltejs/svelte/pull/17819))