No API docs on React Refresh

I was experiencing how useEffect was re-running with empty dependencies due to HMR (which was expected) on changes, but I saw how re-running did not trigger the useEffect cleanup function. This was unexpected and maybe a bug? I thought I would reference the HMR / Fast Refresh docs to verify the expected behaviour before reporting, but I could not find anything (apart from reactnative.dev) on any React owned sites! All docs/articles I could find were on third party sites.

AFAIK, Fast Refresh is the native (as in built-in) React solution to HMR, so it is part of React. That means it has an API exposed to end users, and I would then expect it to be documented. Searching "HMR" or "Fast Refresh" comes up with nothing when using the docs search feature.

I can only find "implicit docs" on Fast Refresh on the issue tracker (such as these by Dan: https://github.com/facebook/react/issues/21019) or on external articles and none mention how the cleanup callback is supposed to work in Fast Refresh mode.

まず、reactnative.dev にある既存の Fast Refresh に関する資料、React ドキュメントで「HMR」と「Fast Refresh」を検索した結果、およびリンクされている issue #21019 を確認します。cleanup コールバックに期待される動作を判断し、React が管理するドキュメントページで Fast Refresh の公開動作と API の概念を文書化します。