Use state hook with an extra "getState" parameter

useStateWithCallback.ts

export function useStateWithCallback<T>(
  defaultState: T | (() => T)
): readonly [T, Dispatch<SetStateAction<T>>, () => Promise<T>] {
  const [state, setState] = useState<T>(defaultState);

  const getState = useCallback(() => {
    return new Promise<T>((resolve) => {
      setState((oldValue) => {
        resolve(oldValue);
        return oldValue;
      });
    });
  }, []);

  return [state, setState, getState] as const;
}

Use: const [count, setCount, getCount] = useStateWithCallback(0)

Then to access current state in a callback:

const currentCount = await getCount();