State Management · Middle · Question 12 of 75

What's wrong with this case reducer?

todoAdded(state, action) {
  state.items.push(action.payload);
  return { ...state, count: state.count + 1 };
}

✓Correct answer: You can't both mutate the Immer draft and return a new value
2push is forbidden inside createSlice reducers
3Case reducers must be async functions

Explanation

Either mutate the draft (state.items.push(...); state.count += 1) or return a completely new state - Immer throws if you do both.

Further reading

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