initialState.js

const initialState = {
  pricingPlans: [],
  pricingPlansWithRepayment: [],
  selectedOptionIdentifier: null,
  selectedPreviewOptionIdentifier: null,
  error: {},
};

function reducer(state = initialState, action = {}) {
  switch (action.type) {
    case actionTypes.RECEIVE_PRICING_PLANS: {
      const { pricingPlans, selectedOptionIdentifier } = action.data;

      return {
        ...state,
        pricingPlans,
        selectedOptionIdentifier: state.selectedOptionIdentifier || selectedOptionIdentifier,
        selectedPreviewOptionIdentifier: state.selectedPreviewOptionIdentifier || selectedOptionIdentifier,
      };
    }
    case actionTypes.RECEIVE_PRICING_PLANS_WITH_REPAYMENT:
      return {
        ...state,
        pricingPlansWithRepayment: action.data.pricingPlans,
      };
    case actionTypes.FETCH_PRICING_PLANS:
      return {
        ...state,
        pricingPlans: [],
        error: {},
      };
    case actionTypes.SELECT_OPTION_IDENTIFIER:
      return {
        ...state,
        selectedOptionIdentifier: action.data,
      };
    case actionTypes.SELECT_PREVIEW_OPTION_IDENTIFIER:
      return {
        ...state,
        selectedPreviewOptionIdentifier: action.data,
      };
    case actionTypes.RECEIVE_PRICING_PLANS_ERROR:
      return {
        ...state,
        ...action.data,
      };
    default:
      return state;
  }
}

export default reducer;