React Redux, trying to add products to cart

I am trying to add products to shopping cart by storing them in local storage but, they are not getting stored. I looked into Redux-dev-tools and found out my state is not updating:

As you can see action is getting fired but my state is not updating:

Here is the source code:

cartAction.js

import axios from "axios"; import { CART_ADD_ITEM, CART_REMOVE_ITEM } from "../constants/cartConstants";

export const addToCart = (id, qty) => async (dispatch, getState) => {  const { data } = await axios.get(`/api/product/${id}`);

  dispatch({
    type: CART_ADD_ITEM,
    payload: {
      productID: data.product._id,
      name: data.product.name,
      image: data.product.image,
      price: data.product.price,
      countInStock: data.product.countInStock,
      qty,
    },   });

  localStorage.setItem("cartItems", JSON.stringify(getState().cart.cartItems)); };

cartReducer.js

import { CART_ADD_ITEM, CART_REMOVE_ITEM } from "../constants/cartConstants";

export const cartReducer = (state = { cartItems: [] }, action) => {
  switch (action.state) {
    case CART_ADD_ITEM:
      const item = action.payload;
      const existItem = state.cartItems.find(
        (x) => x.productID === item.productID
      );

      if (existItem) {
        return {
          ...state,
          cartItems: state.cartItems.map((x) =>
            x.productID === existItem.productID ? item : x
          ),
        };
      } else {
        return {
          ...state,
          cartItems: [...state.cartItems, item],
        };
      }
    // case CART_REMOVE_ITEM:
    //   return {};
    default:
      return state;
  }
};

store.js

import { createStore, combineReducers, applyMiddleware } from "redux";
import thunk from "redux-thunk";
import { composeWithDevTools } from "redux-devtools-extension";

// reducers
import {
  productDetailsReducer,
  productListReducer,
} from "./reducers/productReducers";
import { cartReducer } from "./reducers/cartReducers";

const reducer = combineReducers({
  productList: productListReducer,
  productDetails: productDetailsReducer,
  cart: cartReducer,
});

const cartItemsFromStorage = localStorage.getItem("cartItems")
  ? JSON.parse(localStorage.getItem("cartItems"))
  : [];

const initialState = {
  cart: { cartItems: cartItemsFromStorage },
};
const middleware = [thunk];

const store = createStore(
  reducer,
  initialState,
  composeWithDevTools(applyMiddleware(...middleware))
);

export default store;

CartScreen.js

import React, { useEffect } from "react";
import { useDispatch, useSelector } from "react-redux";
import { addToCart, removeFromCart } from "../../redux/actions/cartActions";
import { Link } from "react-router-dom";
import ErrorMessage from "../../components/ErrorMessage/ErrorMessage";
import "./CartScreen.scss";

const CartScreen = ({ match, location, history }) => {
  const productID = match.params.id;

  const qty = location.search ? Number(location.search.split("=")[1]) : 1;

  const dispatch = useDispatch();

  const cart = useSelector((state) => state.cart);
  const { cartItems } = cart;

  console.log(cartItems);
  useEffect(() => {
    if (productID) {
      dispatch(addToCart(productID, qty));
    }
  }, [dispatch, productID, qty]);

  return (
    <>
      <h1>Shopping Cart</h1>
    </>
  );
};

export default CartScreen;

Answer

You need to fix this on CartReducer.js

switch (action.state) {

to

switch (action.type) {