Counter Reducer

counterReducer.ts

// Rest of the file omitted

const incrementReducer = (
  counter: StateSliceType,
  action: ActionType,
): StateSliceType => {
  const interactor = new CounterInteractor(counter);
  interactor.increment(action.qty);
  return new Counter(interactor.counter.count);
};

export const counterReducer = (
  state: StateSliceType = INITIAL_STATE,
  action: ActionType,
): StateSliceType => {
  switch (action.type) {
    case INCREMENT:
      return incrementReducer(state, action);
    case DECREMENT:
      return decrementReducer(state, action);
    default:
      return state;
  }
};