# Svelte changelog ## Unreleased * Add a11y warning `a11y-role-has-required-aria-props` which checks that elements with `role` attribute has all required attributes for that role. ([#5852](https://github.com/sveltejs/svelte/pull/5852)) * Add a11y warning `aria-proptypes` which checks ARIA state and property values ([#6978](https://github.com/sveltejs/svelte/pull/6978)) * Add a11y warning `a11y-no-abstract-role` which checks ARIA roles must be non-abstract ARIA role ([#6241](https://github.com/sveltejs/svelte/pull/6241)) ## 3.49.0 * Improve performance of string escaping during SSR ([#5701](https://github.com/sveltejs/svelte/pull/5701)) * Add `ComponentType` and `ComponentProps` convenience types ([#6770](https://github.com/sveltejs/svelte/pull/6770)) * Add support for CSS `@layer` ([#7504](https://github.com/sveltejs/svelte/issues/7504)) * Export `CompileOptions` from `svelte/compiler` ([#7658](https://github.com/sveltejs/svelte/pull/7658)) * Fix DOM-less components not being properly destroyed ([#7488](https://github.com/sveltejs/svelte/issues/7488)) * Fix `class:` directive updates with `` ([#7521](https://github.com/sveltejs/svelte/issues/7521), [#7571](https://github.com/sveltejs/svelte/issues/7571)) * Harden attribute escaping during SSR ([#7530](https://github.com/sveltejs/svelte/pull/7530)) ## 3.48.0 * Allow creating cancelable custom events with `createEventDispatcher` ([#4623](https://github.com/sveltejs/svelte/issues/4623)) * Support `{@const}` tag in `{#if}` blocks [#7241](https://github.com/sveltejs/svelte/issues/7241) * Return the context object in `setContext` [#7427](https://github.com/sveltejs/svelte/issues/7427) * Allow comments inside `{#each}` blocks when using `animate:` ([#3999](https://github.com/sveltejs/svelte/issues/3999)) * Fix `|local` transitions in `{#key}` blocks ([#5950](https://github.com/sveltejs/svelte/issues/5950)) * Support svg namespace for `{@html}` ([#7002](https://github.com/sveltejs/svelte/issues/7002), [#7450](https://github.com/sveltejs/svelte/issues/7450)) * Fix `{@const}` tag not working inside a component when there's no `let:` [#7189](https://github.com/sveltejs/svelte/issues/7189) * Remove extraneous leading newline inside `
` and `