[lexical-website] Documentation Update: clarify Yjs custom node property syncing

[Vedthakar]

Description

Closes #7280

This PR documents an important constraint of Lexical collaboration with Yjs: custom node properties are only reliably synced when they are own enumerable properties of the node.

To make that behavior clear for consumers implementing custom nodes without NodeState, the docs now explain that node properties should be explicitly initialized in the constructor, even when the intended initial value is undefined. This avoids cases where optional properties are not present as own enumerable fields and therefore are not reliably synced during collaboration.

The documentation also points readers toward NodeState as the preferred approach, since it avoids this class-property syncing pitfall and has better built-in support for collaboration use cases.

What changed

• added/updated documentation describing how Yjs syncs custom node properties
• clarified that properties should be initialized in the constructor if a node relies on instance properties instead of NodeState
• reinforced the recommendation to use NodeState where possible

Why

Without this note, it is easy for consumers to define optional node properties using class field syntax and assume they will participate in collab syncing automatically. In practice, this can lead to confusing behavior because only own enumerable properties are reliably synchronized.

This PR makes that constraint explicit so custom node implementations are less likely to break in collaborative editors.

Test plan

Before

The relevant behavior existed, but it was easy to miss or misunderstand when implementing custom nodes for collaborative editing.

After

• verified the documentation now clearly describes the Yjs syncing constraint
• verified the guidance points developers toward explicit constructor initialization or NodeState

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
lexical	Ready	Preview, Comment	Apr 7, 2026 0:11am
lexical-playground	Ready	Preview, Comment	Apr 7, 2026 0:11am

[etrepum]

I don't think this is a good way to do this, would be better to handle it as a separate page entirely (you can see how pages are configured in vite.config.ts) or even to create a new package specifically for self-contained e2e tests.

There's also nothing that actually invokes this repro (I would expect it to be the subject of an e2e test), and it's related to a completely separate issue so it certainly doesn't belong in this PR.