Fix List issues & add support for Mod keys

[bdbch]

Please describe your changes

This PR fixes various issues with lists (for example when the cursor is placed right behind a list and backspace is pressed).

It also moves all list helpers into core so they can be used by taskLists too.

Checklist

• The changes are not breaking the editor
• Added tests where possible
• Followed the guidelines
• Fixed linting issues

Related Issues

closes #3128
closes #2747

[netlify]

✅ Deploy Preview for tiptap-embed ready!

Name	Link
🔨 Latest commit	2a11d39
🔍 Latest deploy log	https://app.netlify.com/sites/tiptap-embed/deploys/64affebc3a13d0000896d17e
😎 Deploy Preview	https://deploy-preview-4210--tiptap-embed.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[terlan4]

When will this version be released? I would love to see my backspace work asap 🙂❤

[bdbch]

@svenadlung could you take a look?

[Nantris]

I was looking through these changes and I'm curious what the changes to the cut command accomplished? I'm curious because we're reliant on that command in our own code. Was there some mapping-related issue with the old implementation?

[bdbch]

If I remember correctly the issue occured when something was cut and moved after the cut content. Since the mapping wasn't respected beforehand, the insert position was invalid.

I could check again if I find some time what it was about exactly.

[Nantris]

I also noticed the logic in these Backspace handler lines lacks corresponding logic in the Delete handler:

tiptap/packages/core/src/helpers/listHelpers/handleBackspace.ts

Lines 20 to 42 in 2a11d39

	if (!isNodeActive(editor.state, name) && hasListBefore(editor.state, name, parentListTypes)) {
	const { $anchor } = editor.state.selection
	const $listPos = editor.state.doc.resolve($anchor.before() - 1)
	const listDescendants: Array<{ node: Node, pos: number }> = []
	$listPos.node().descendants((node, pos) => {
	if (node.type.name === name) {
	listDescendants.push({ node, pos })
	}
	})
	const lastItem = listDescendants.at(-1)
	if (!lastItem) {
	return false
	}
	const $lastItemPos = editor.state.doc.resolve($listPos.start() + lastItem.pos + 1)
	return editor.chain().cut({ from: $anchor.start() - 1, to: $anchor.end() + 1 }, $lastItemPos.end()).joinForward().run()
	}

[Nantris]

If I remember correctly the issue occured when something was cut and moved after the cut content. Since the mapping wasn't respected beforehand, the insert position was invalid.

Thanks for the reply @bdbch! I was curious looking at it because it seems similar to the weird mapping misbehavior in #4283

Edit: Seems pretty likely to me actually since all the mapping issues I hit were related to chained commands on lists specifically.