Fix Slate component to properly handle editor updates by adding `edit…

[changlin-cn]

Description
In packages/slate-react/src/components/slate.tsx, the useIsomorphicLayoutEffect that subscribes to document focusin/focusout (or focus/blur) uses a callback that reads editor, but the effect has an empty dependency array []. That causes a stale closure: the listener fn always refers to the editor from the first render. If the parent ever passes a different editor instance (e.g. after remount or when editor is recreated), the effect does not re-run, so the document-level listeners keep calling ReactEditor.isFocused(editor) with the old editor. That can lead to wrong isFocused state in context and, in edge cases, to using an unmounted or replaced editor.

Issue
Fixes: Bug: Stale editor in focus listener effect in Slate component

[changeset-bot]

🦋 Changeset detected

Latest commit: 89a18de

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
slate-react	Patch

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[dylans]

This may be on purpose, but I'm not remembering. Maybe @12joan remembers?

Also this will need a changeset to get released if it is needed.

[12joan]

It looks like an accidental omission to me, especially since the useEffect above has no purpose other than to support the editor being replaced.

  const [isFocused, setIsFocused] = useState(ReactEditor.isFocused(editor))

  useEffect(() => {
    setIsFocused(ReactEditor.isFocused(editor))
  }, [editor])

[jsauca]

Here is quick fix for me:

  // Force Slate remount when the editor instance changes
  // slate-react's focusin/focusout listener has [] deps, capturing the initial
  // editor forever — remounting resets the closure with the correct editor.
  const slateKeyRef = useRef(0);
  const prevEditorRef = useRef(editor);
  if (editor !== prevEditorRef.current) {
    prevEditorRef.current = editor;
    slateKeyRef.current += 1;
  }

<Slate
    key={slateKeyRef.current}
  />

[changlin-cn]

This may be on purpose, but I'm not remembering. Maybe @12joan remembers?

Also this will need a changeset to get released if it is needed.

If this is intentional, it will cause the useFocused hook to return an incorrect value after the editor instance is recreated. Additionally, the changeset has been updated.