Bug: React.memo fails to memoize component about react

[MrWangJustToDo]

because <ParentMemo /> have a children props, which will create by <App /> when every rerender (<ChildMemo /> = jsx(ChildMemo), and this will return a new object when invoke), try to change you code to:

const ele =  <ChildMemo />;

function App() {
  useEffect(() => {
    console.log("App rerender");
  });
  const [count, setCount] = useState(0);

  return (
    <>
      <button onClick={() => setCount(count + 1)}>Update state {count}</button>
      <ParentMemo>
         {ele}
      </ParentMemo>
    </>
  );
};

now the children props for <ParentMemo /> will never change, and <ParentMemo /> component also will not update by now