text: import {
      SET_SHOP_CATEGORIES,
      SET_SHOP_PRODUCTS,
      FILTER_PRODUCTS_WITH_CATEGORY_ID,
      FILTER_PRODUCTS_WITH_QUERY
  } from '../actions/types';
  
  const INITIAL_STATE = {
      categories: [],
      selectedCategoryId: 0,
      products: [],
      filteredProducts: []
  }
  
  export default function(state = INITIAL_STATE, action) {
      switch (action.type) {
          case SET_SHOP_CATEGORIES:
              const categories  = action.payload;
              return {
                  ...state,
                  categories
              }
          case SET_SHOP_PRODUCTS:
              return {
                  ...state,
                  products: action.payload
              }
          case FILTER_PRODUCTS_WITH_CATEGORY_ID:
              var filteredProducts = [];
              state.products.map(product => {
                  if(product.belongsTo.includes(action.payload)) {
                      filteredProducts.push(product);
                  }
              })
              return {
                  ...state,
                  filteredProducts
              }
          case FILTER_PRODUCTS_WITH_QUERY: 
              var filteredProducts = [];            
              state.products.map(product => {
                  if(product.title.toLowerCase().includes(action.payload.query.toLowerCase())) {
                      filteredProducts.push(product)
                  }
              })
              return {
                  ...state,
                  filteredProducts
              }
          default: return state;
      }
  }