bug(richtext-lexical): pasting an <hr> into the editor throws "Create node: Type horizontalrule ... does not match registered node ... with the same type"

[MSelcukAkbas]

Describe the Bug

Pasting HTML that contains an <hr> element into a Lexical richText field in the admin UI throws immediately and the paste is dropped. The console shows:

Error: Create node: Type horizontalrule in node HorizontalRuleServerNode does not match registered node HorizontalRuleNode with the same type

(followed by a secondary TypeError: Cannot read properties of undefined (reading 'values') from Lexical's garbage collector, since the editor is left in an inconsistent state after the first error.)

Root cause

HorizontalRuleServerNode.importDOM() (packages/richtext-lexical/src/features/horizontalRule/server/nodes/HorizontalRuleNode.tsx) hardcodes its DOM-paste conversion to always construct a HorizontalRuleServerNode:

static override importDOM(): DOMConversionMap | null {
  return {
    hr: () => ({
      conversion: $convertHorizontalRuleElement, // always returns $createHorizontalRuleServerNode()
      priority: 0,
    }),
  }
}

The admin/editor client, however, registers the client subclass HorizontalRuleNode (packages/richtext-lexical/src/features/horizontalRule/client/nodes/HorizontalRuleNode.tsx) under the same Lexical node type 'horizontalrule'. That subclass does not override importDOM, so it inherits the base implementation above — which is hardcoded to the base class rather than being polymorphic over this.

When Lexical's internal HTML→Lexical converter runs importDOM during paste, it ends up trying to instantiate HorizontalRuleServerNode even though the editor's node registry expects 'horizontalrule' to produce a HorizontalRuleNode instance, which throws Lexical's built-in class-identity check (errorOnTypeKlassMismatch).

Note importJSON does not have this problem, because the client subclass explicitly overrides it and calls its own $createHorizontalRuleNode(). It's specifically the DOM-paste path that's affected.

Reproduction Steps

1. npx create-payload-app (or clone templates/blank) with Payload 3.90.1, default lexicalEditor(), any DB adapter.
2. Add any collection with a richText field (default Lexical editor, no custom node config needed — the default set already includes horizontalRule).
3. Open the admin UI, create a new document, click into the richText field.
4. Paste HTML containing an <hr>, e.g. copy <p>a</p><hr><p>b</p> to the clipboard (or paste from any source that produces an <hr> — a Markdown-rendered page, Word content, another Lexical instance, etc.) and paste it into the field.

Expected: the horizontal rule (and surrounding paragraphs) is inserted into the editor.

Actual: the console throws the error above and the paste is dropped; the editor content does not change.

Environment

• payload: 3.90.1
• @payloadcms/richtext-lexical: 3.90.1
• @payloadcms/db-sqlite (adapter used in reproduction; not adapter-specific — this is purely a Lexical node-registration bug and is independent of the database)
• next: 16.3.3
• react / react-dom: 19.2.6
• Node: v24.14.0
• OS: Windows 11

Confirmed still present (code unchanged) on 3.91.0-internal.6e3dc85 and 4.0.0-canary.36 as of 2026-09-23.

Suggested fix

Verified locally: build the node in importDOM from this instead of the hardcoded base class, so a subclass registered under the same type produces an instance of itself. After applying this change to the installed package, the same paste inserts the <hr> correctly with no console errors.

static override importDOM(): DOMConversionMap | null {
  const NodeClass = this
  return {
    hr: () => ({
      conversion: (): DOMConversionOutput => ({
        node: $applyNodeReplacement(new NodeClass()),
      }),
      priority: 0,
    }),
  }
}

A pull request with this fix will follow shortly.