Function Sibling

packages/react-reconciler/src/__tests__/ReactAsyncActions-test.js:1269–1284

()

      let setText;
      let setOptimisticText;
      function Sibling() {
        const [canonicalText, _setText] = useState('A');
        setText = _setText;

        const [text, _setOptimisticText] = useOptimistic(
          canonicalText,
          (_, optimisticText) => `${optimisticText} (loading...)`,
        );
        setOptimisticText = _setOptimisticText;

        return (
          <span>
            <Text text={text} />
          </span>
        );
      }

      function App({showUpdater}) {
        return (