docs: "What's new in Svelte" November newsletter (#881)

* first draft of dec newsletter

* Apply suggestions from code review

Co-authored-by: Ben McCann <[email protected]>
Co-authored-by: Paolo Ricciuti <[email protected]>

* It's december!

* Forgot to update the description

* Update apps/svelte.dev/content/blog/2024-12-01-whats-new-in-svelte-december-2024.md

* Update 2024-12-01-whats-new-in-svelte-december-2024.md

---------

Co-authored-by: Ben McCann <[email protected]>
Co-authored-by: Paolo Ricciuti <[email protected]>
Co-authored-by: Simon H <[email protected]>

Author: 4 people

apps/svelte.dev/content/blog/2024-12-01-whats-new-in-svelte-december-2024.md

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+---
+title: "What's new in Svelte: December 2024"
+description: 'A better CLI and a bunch of UI libraries now support Svelte 5'
+author: Dani Sandoval
+authorURL: https://dreamindani.com
+---
+
+I can't believe it's already the last newsletter of the year! So much has happened in the Svelte community - from two great Svelte Summits to the release Svelte 5 🎉
+
+As we look forward to the next year and watch the Svelte team do [24 features in 24 days](advent-of-svelte), let's dive into what's new in the past month...
+
+## What's new in Svelte
+
+The bugfix versions in 5.1.x and 5.2.x addressed a bunch of issues reported by the community. So if you're noticing anything weird, make sure you upgrade to the latest version and, as always, check out the [CHANGELOG](https://github.com/sveltejs/svelte/blob/main/packages/svelte/CHANGELOG.md) for all the bug fixes.
+
+The features since last month can be found below:
+
+- `ContentVisibilityAutoStateChangeEvent` has been added to element definitions (**5.2.5**, [MDN Docs](https://developer.mozilla.org/en-US/docs/Web/API/ContentVisibilityAutoStateChangeEvent), [#14373](https://github.com/sveltejs/svelte/pull/14373))
+
+## What's new in SvelteKit, Svelte CLI and Language Tools
+
+- `isActionFailure` is a new helper method to check if a variable is an instanceof `ActionFailure` - helpful for debugging parsing of user input (**2.8.0**, [#12878](https://github.com/sveltejs/kit/pull/12878))
+- `const load = ...` declarations will now be typed automatically (**svelte2tsx-0.7.23**, [#2540](https://github.com/sveltejs/language-tools/pull/2540))
+- The CLI will now include a `jsconfig.json` in the 'no type checking' template (**0.6.2**, [#290](https://github.com/sveltejs/cli/pull/290))
+- When installing dependencies, the CLI will display the package manager's output (**0.6.3**, [#305](https://github.com/sveltejs/cli/pull/305))
+- A short description will now be shown for each add-on in the CLI menu (**0.6.5**, [#299](https://github.com/sveltejs/cli/pull/299))
+- Instance types will now be provided automatically in Svelte 5 (**svelte2tsx-0.7.23**, [#2553](https://github.com/sveltejs/language-tools/pull/2553))
+- A code lens indicator for "runes mode" will now appear atop a file when detected - "legacy mode" when not (**language-server-0.17.4**, [#2554](https://github.com/sveltejs/language-tools/pull/2554))
+
+---
+
+## Community Showcase
+
+### Apps & Sites built with Svelte
+
+- [Unsubscribe](https://unsubscribe.jnr.cx/) is an interactive site that makes fun of how hard it is to unsubscribe from things on the internet these days
+- [Dealcrane](https://dealcrane.com/?utm_source=discord&utm_medium=social&utm_campaign=beta_promo&utm_content=svelte) helps technology shoppers find discounts across popular internet shopping sites
+- [Raw Web](https://rawweb.org/) is a search engine for indexing the content of independent, especially personal, websites
+- [Jovian Moon's personal site](https://github.com/StephenGunn/jovian) features an interactive rocket ship to fly you straight to Jupiter (or anywhere else you want to go)
+- [Font Preview](https://github.com/songkeys/font-preview) makes it easy to analyze and explore font characters in the browser
+- [Dunks & Threes](https://dunksandthrees.com/) is a professional basketball analysis platform that provides data-driven NBA predictions
+- [AdresseDuBien](https://adressedubien.com/) is a small utility to find addresses for real estate ads (for France) with a Libre Map implementation
+- [PixelAttack](https://jason1610.github.io/PixelAttack/) takes an image, pixelizes it and makes the pixels fight each other
+- [NeoHtop](https://github.com/Abdenasser/neohtop) is a modern, process monitoring tool that combines the power of terminal-based system monitors with a clean, desktop-native UI
+- [WebVM](https://github.com/leaningtech/webvm) is a Linux virtual machine that runs in your browser
+- [Sveltris](https://svelte.dev/playground/8594eea15c6244908c3efad284fe2aa4?version=5.2.1) is Tetris built entirely in the Svelte REPL
+
+### Learning Resources
+
+_Featuring Svelte Contributors and Ambassadors_
+
+- [Svelte 🧡](https://bsky.app/profile/paolo.ricciuti.me/feed/svelte-feed) is a Bluesky feed to keep up to date on Svelte news in that application
+- [SvelteKit Streaming: The Complete Guide](https://khromov.se/sveltekit-streaming-the-complete-guide/) by Stanislav Khromov
+- [Remote Workshop: Svelte 5 & Runes](https://ti.to/mainmatter/svelte-5-runes-feb-2025) is taking place February 6-7th, 2025 and taught by Paolo Ricciuti
+- [Svelte 5: In Action | Build A Tasks App](https://www.youtube.com/watch?v=uSWMvDPpG0k) by Syntax
+- [Svelte Society London](https://www.youtube.com/watch?v=mxM208nCvHc) - featuring Paolo with his talk, _Herd your async tasks!_
+
+_This Week in Svelte_
+
+- [Ep. 83](https://www.youtube.com/watch?v=1a-iKUCF5_g) — You might not need an effect
+- [Ep. 84](https://www.youtube.com/watch?v=kVbQyKf4Oe4) — manifest.build
+- [Ep. 85](https://www.youtube.com/watch?v=yY963ovcDQ0) — @sheepdog/svelte
+
+_To Read_
+
+- [Web software development (2024)](https://fitech101.aalto.fi/web-software-development/) is a self-study course for all things web development and features Svelte heavily
+- [Async Fetching in Svelte 5](https://dev.to/jdgamble555/async-fetching-in-svelte-5-826) by Jonathan Gamble
+- [Cross-Origin-Isolation with SvelteKit, Vite, and Firebase](https://www.captaincodeman.com/cross-origin-isolation-with-sveltekit-vite-and-firebase) by Captain Codeman
+- [The $effect.tracking rune](https://www.matsimon.dev/blog/svelte-in-depth-effect-tracking) by Matt Simon
+
+### Libraries, Tools & Components
+
+_Component Libraries_
+
+- [shadcn-svelte](https://next.shadcn-svelte.com/) now supports Svelte 5 and has brand new docs to go with the update
+- [Zag](https://zagjs.com/overview/introduction) now supports Svelte 5
+- [Skeleton V3](https://github.com/skeletonlabs/skeleton/discussions/2919) is now in beta (and, as expected, supports Svelte 5)
+- [Storybook 8.4](https://www.reddit.com/r/sveltejs/comments/1gpqusy/storybook_84_release/) now supports Svelte 5 and CSF natively with component testing built-in
+
+_Icon Libraries_
+
+- [svelicon](https://github.com/friendofsvelte/svelicon) converts Iconify SVG icons to type-safe components with one command
+- [moving icons](https://www.movingicons.dev/) is a collection of animated icons based on the lucide icon library
+- [Monicon](https://github.com/oktaysenkan/monicon) is an all-in-one icon library that provides 200,000+ icons from popular sets like Material Design, Feather, and Font Awesome
+
+_Everything Else_
+
+- [Svelte Multitone Image](https://stephane-vanraes.github.io/svelte-multitoneimage/) is a simple image renderer to apply multitone effects for Svelte
+- [number-flow](https://github.com/barvian/number-flow) is a component to transition, format, and localize numbers
+- [sveltednd](https://github.com/thisuxhq/SvelteDnD) is a lightweight, flexible drag and drop library for Svelte 5 applications
+- [ShadEditor](https://github.com/Tsuzat/ShadEditor) is a highly extensible text editor for svelte made with TipTap and ShadCN UI
+- [Tipex](https://www.npmjs.com/package/@friendofsvelte/tipex) is an advanced rich text editor based on Tiptap and Prosemirror
+- [svelte-bundle](https://github.com/uhteddy/svelte-bundle) is a tool for bundling Svelte components into a single HTML file
+- [svelte5-router](https://github.com/mateothegreat/svelte5-router) is an SPA router that allows you to divide & conquer your app with nested routers
+- [@sheepdog/svelte](https://github.com/mainmatter/sheepdog) is a library to manage async tasks and concurrency with ease.
+
+That's it for this huge month in Svelte! Let us know if we missed anything on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.gg/svelte).
+
+Until next ~~time~~ year! 👋