Intended behavior: https://github.com/reactwg/react-18/discussions/31

Sandbox: https://codesandbox.io/s/react-18-layouteffect-semantics-forked-m02w5

Expected: when suspended content is hidden and then shown, we get layout cleanup followed by layout setup.
Actual: only layout cleanup happens.


markCommitTimeOfFallback();
    if (supportsMutation) {
       
       
       
       
       
       
       
       
       
      const primaryChildParent: Fiber = (finishedWork.child: any);
      hideOrUnhideAllChildren(primaryChildParent, true);
    }
  }
  if (enableSuspenseCallback && newState !== null) {
    const suspenseCallback = finishedWork.memoizedProps.suspenseCallback;
    if (typeof suspenseCallback === 'function') {
      const wakeables: Set<Wakeable> | null = (finishedWork.updateQueue: any);
      if (wakeables !== null) {
        suspenseCallback(new Set(wakeables));
      }
    } else if (__DEV__) {
      if (suspenseCallback !== undefined) {
        console.error('Unexpected type for suspenseCallback.');
      }
    }
  }
}
function commitSuspenseHydrationCallbacks(