React 18: implementing Nested State Updates Leading to Unexpected Re-renders
I'm working with a frustrating question with state updates in my React 18 application. I'm using `useState` to manage a nested state object, and it seems to trigger unnecessary re-renders, affecting performance. Specifically, I have a form with multiple fields grouped in a single state object: ```javascript const [formData, setFormData] = useState({ user: { name: '', email: '', }, preferences: { newsletter: false, notifications: true, }, }); ``` When I update a field, I spread the previous state to ensure I do not lose the other values: ```javascript const handleChange = (e) => { const { name, value } = e.target; setFormData((prev) => ({ ...prev, user: { ...prev.user, [name]: value, }, })); }; ``` However, even when I only update the `name` field, it seems like the whole component re-renders, and I see a performance drop, especially when the form grows. I also get warnings in the console about the function's dependency array in `useEffect`, indicating that the entire `formData` object is being treated as a dependency, which triggers effects unnecessarily. I tried using `useReducer`, thinking it might handle state updates more efficiently, but I'm still working with the same issues. I have implemented a `React.memo` on the component but it doesn’t seem to help either. Am I missing something fundamental about state management in React 18, or is it just how nested updates work? Any guidance or best practices would be greatly appreciated!