Difficulty Merging Two Arrays of Objects in React State Management Using Immer
I'm facing an issue while trying to merge two arrays of objects in my React state using the Immer library. I have two arrays, `arrayA` and `arrayB`, each containing objects with a unique `id`. The goal is to merge them into a single array in the state while ensuring that if an object from `arrayB` has the same `id` as an object from `arrayA`, it should replace the one in `arrayA`. Here’s a simplified example of what I have: ```javascript const initialState = { items: [ { id: 1, name: 'Item 1' }, { id: 2, name: 'Item 2' } ] }; const reducer = produce((draft, action) => { switch (action.type) { case 'MERGE_ITEMS': const arrayA = draft.items; const arrayB = action.payload; const merged = [...arrayA]; arrayB.forEach(itemB => { const index = merged.findIndex(itemA => itemA.id === itemB.id); if (index !== -1) { merged[index] = itemB; // Replace object in arrayA } else { merged.push(itemB); // Add new object } }); draft.items = merged; break; default: break; } }, initialState); ``` However, when I dispatch an action with `arrayB` like this: ```javascript const arrayB = [ { id: 1, name: 'Updated Item 1' }, { id: 3, name: 'Item 3' } ]; dispatch({ type: 'MERGE_ITEMS', payload: arrayB }); ``` I get an unexpected state where `items` contains duplicates. The objects seem to be getting merged correctly, but I still see both `Item 1` and `Updated Item 1` in the final state: ```javascript console.log(state.items); // Expected: [{ id: 1, name: 'Updated Item 1' }, { id: 2, name: 'Item 2' }, { id: 3, name: 'Item 3' }] // Actual: [{ id: 1, name: 'Item 1' }, { id: 2, name: 'Item 2' }, { id: 3, name: 'Item 3' }] ``` I’ve tried logging out the `merged` array before assigning it to `draft.items`, and it appears to be merging correctly. Could this be an issue with how Immer handles state updates, or am I missing something in my logic? I'm using Immer version 9.0.0 and React version 17.0.2. Any help would be greatly appreciated!