v4.0.0-rc.2

[jonasgeiler]

About

The third release candidate for v4.0.0 is here!
It contains many improvements that I found by looking at the code for way too long. I ended up changing quite a lot, which technically shouldn't happen between two release candidates, but I don't have any other release options at the moment 😅

Most importantly, I have deprecated the children snippet, and you should useitem instead, similar to how the slot was called in v3.0.0 and earlier versions.
The same applies to the onListItemsUpdate callback, where you should use onItemsUpdated instead, inspired by the naming of the event from v3.0.0 and earlier versions.
These two changes are backwards compatible, so you may see a TypeScript warning, but everything will remain functional until a potential v5.0.0 in the future, where deprecated APIs will be removed.
So I still recommend changing it!

I've hopefully also fixed the typings. This should help with errors, warnings, and the general development experience.

I promise that I won't change much more, if anything, until the final v4.0.0 release :D

What's Changed

• ⚠️ Deprecation of children snippet. Use item instead!
• ⚠️ Deprecation of onListItemsUpdate callback. Use onItemsUpdated instead!
• Improve component typings
• Add svelte-check tool to verify typings
• Improve performance and simplify SizeAndPositionManager
• Bring back some old types that existed in v3.0.0
• Actually export the correct types
• Stop using $state for bind:this
• Change height default to '100%'
• Get rid of Element.scroll(...) legacy fallback since older browsers are not supported anymore anyways

• refactor: get rid of ListProps and ListState classes by putting it directly in component by @jonasgeiler in refactor: get rid of ListProps and ListState classes by putting it directly in component #105

Full Changelog: v4.0.0-rc.1...v4.0.0-rc.2

Sponsors

Thank you to my first ever GitHub Sponsor, Jakob Kruse (@jakob-kruse)!!! 💖
Do you also want to appear here? Sponsor me!

[webJose]

Thanks for the efforts. I'm waiting on it to see if I can add this to this table: https://github.com/WJSoftware/wjfe-dataview

FYI, and maybe this is useful for you: I made a Devtools extension that tells you the number of child elements in a node, and which ones are visible. I made this to measure the potential benefits of virtualization. The extension is not published in the Chrome store, but you can build it yourself and add it in Developer Mode: https://github.com/webJose/DomDescendantCounter

Note

DOM Descendant Counter was half-vibed with Claude Sonnet 4, hence the flashy README. I vibed it because it is undeniable that AI CAN code, and as a professional I need to learn how to use it. There might be some superflous code here and there. I did supervise and review the work, though. The extension delivers.