How to change object field value in store array in redux?

Question

JavaScript

The store array stores objects that have a count field. On the CHANGE_ITEM_COUNT event, the count value of a certain element changes depending on the action that comes in the payload along with the id of this element. Now the task is to dynamically update the store array, replacing the old object with a new one and so that the order is preserved. How can this be implemented?

case CHANGE_ITEM_COUNT:

      const itemCount = state.find(({id}) => id === action.payload.id);
      if (action.payload.action === 'decrement' && itemCount.count > 1) {
        itemCount.count--
      }
      if (action.payload.action === 'increment') {
        itemCount.count++
      }

Answer 1

case CHANGE_ITEM_COUNT:
  return state.map(n => n.id === action.payload.id
    ? {
        ...n,
        count: Math.max(1, n.count + (({
          increment:  1,
          decrement: -1,
        })[action.payload.action]) || 0),
      }
    : n
  );