How to Handle Immutability When Updating Elements of a Nested Array in React State Management?
I've been researching this but I tried several approaches but none seem to work. I'm working on a React application using version 17.0.2, and I'm working with an scenario with properly updating a nested array in the state while adhering to immutability principles. I have a state structure that looks like this: ```javascript const [data, setData] = useState([ { id: 1, name: 'Item 1', details: { count: 10, status: 'active' } }, { id: 2, name: 'Item 2', details: { count: 5, status: 'inactive' } } ]); ``` My goal is to update the `count` of `Item 1` from `10` to `15` based on some event, but when I try to do this, I keep getting the behavior `want to read property 'count' of undefined`. Here’s the code I’m using to perform the update: ```javascript const updateItemCount = (id, newCount) => { const updatedData = data.map(item => { if (item.id === id) { item.details.count = newCount; // This mutates the original state! } return item; }); setData(updatedData); }; ``` I realize that I'm directly mutating the nested object, which goes against React's state management principles. I've tried using the spread operator to create a new object, but I’m unsure how to handle the nested structure properly without losing the immutability. I attempted this approach: ```javascript const updateItemCount = (id, newCount) => { const updatedData = data.map(item => { if (item.id === id) { return { ...item, details: { ...item.details, count: newCount } }; } return item; }); setData(updatedData); }; ``` Yet, I still encounter unexpected behavior: the state does not seem to update as expected when I log `data` right after calling `setData(updatedData)`. I suspect it's a closure scenario, or it could be related to asynchronous state updates. Any suggestions on how to properly handle this update while ensuring that the state remains immutable and correctly reflects the changes? What am I doing wrong? My team is using Javascript for this desktop app.