# What's new in Svelte: October 2020

DevFeed: [What's new in Svelte: October 2020](<https://devfeed.tech/articles/what-s-new-in-svelte-october-2020-3116.md>)

Original publisher: [Read original article](<https://svelte.dev/blog/whats-new-in-svelte-october-2020>)

Author: Dani Sandoval

Published: 2020-10-01T00:00:00Z

Content type: release

Language: en

Sources: [Svelte blog](<https://devfeed.tech/sources/svelte-blog.md>)

Topics: [releases](<https://devfeed.tech/topics/releases.md>), [Web Development](<https://devfeed.tech/topics/web-development.md>)

Tags: [bug](<https://devfeed.tech/tags/bug.md>), [changelog](<https://devfeed.tech/tags/changelog.md>), [css](<https://devfeed.tech/tags/css.md>), [features](<https://devfeed.tech/tags/features.md>), [releases](<https://devfeed.tech/tags/releases.md>), [svelte](<https://devfeed.tech/tags/svelte.md>), [typescript](<https://devfeed.tech/tags/typescript.md>), [vs-code](<https://devfeed.tech/tags/vs-code.md>)

## AI overview

An October 2020 Svelte update covering new framework features, fixes, TypeScript event-dispatch typing, and Sapper 0.28.9 improvements.

## Source excerpt

Welcome to the first edition of our "What's new in Svelte" series! We'll try to make this a monthly blog post in which you'll find out about new features, bug fixes, and a showcase of Svelte projects from around the community. New features use:obj.method allows functions defined within objects to be used within actions (Example, 3.26.0, warning removed in 3.27.0) _ is now supported as a "numerical separator", similar to a . or , (Example, 3.26.0) import.meta now works in template expressions (Example, 3.26.0) CSS Selectors with ~ and + combinators are now supported (Example, 3.27.0, with a compiler fix in 3.29.0) The {#key} block is now available to key arbitrary content on an expression. Whenever the expression changes, the contents inside the {#key} block will be destroyed and recreated. For an in-depth explanation and to find out how it's implemented, check out the new blog post of Svelte Team member Tan Li Hau. (More info, 3.29.0) Slots can now be forwarded through child components! This used to only be possible by adding extra wrapper <div>s (More info, 3.29.0) When using TypeScript, you can now type the createEventDispatcher method: <script lang="ts"> import { createEventDispatcher } from 'svelte'; const dispatch = createEventDispatcher<{ /** * you can also add docs */ checked: boolean; // Will translate to `CustomEvent<boolean>` hello: string; }>(); // ... </script> This will make sure that you can invoke dispatch only with the specified event names and its types. The Svelte for VS Code extension was also updated to deal with this new feature. It will provide strong typings for these events as well as autocompletion and hover information. New from Sapper! Sapper 0.28.9 just came out. The highlights from it include much better support for CSP nonces, asset preload support for exported pages, and error details are now available in the $page store on error pages. In addition, Sapper's CSS handling has been rewritten over the course of recent releases in order to