So basically I am creating a invoicing application where user can create bills ( add items to bills by scanning bar code ) user can also add item by specifically typing the itemid ( which exists in their inventory )

• First Function

const handleAddItemById = async (provideditemid) => {
    const AuthToken = localStorage.getItem("AuthToken");
    const itemId = provideditemid ? provideditemid : billDetails.itemId;
    console.log(itemId)
    const response = await fetch(
      `${Base_Url}/inventory/getone?itemId=${itemId}`,
      {
        method: "GET",
        headers: {
          "content-type": "application/json",
          authorization: AuthToken,
        },
      }
    );
    const json = await response.json();
    if (response.ok){
      addItem(json.item);
    } else {
      toast.error(json.msg);
    }
    cleanInputid();
  };

( This function can be called without an argument or with an argument, it gets called without argument when i add item by input method ( that is by manually typing input id ) and it gets called with a argument ( argument is a itemid ) when i scan barcode )
if the response if okay this function calls the “addItem” function with the whole item object as argument.
The json.item looks something like this —
{user : “[email protected]”
Itemname :”donut”
price :30
Quantity :4
ItemsOnDiscount :2
DiscountP :10
DiscountV :3
ItemId :21}

First Function Now calls Second Function —

• Second function

  const addItem = async (newItem) => {
    const ItemExistsInPrevAdded = alreadyAddedbillItems.some(
      (existingItem) => existingItem.ItemId === newItem.ItemId
  );
  console.log("alreadyAddedbillItems : ", alreadyAddedbillItems)
  console.log("PrevaddeditemsExists :" ,ItemExistsInPrevAdded)
    if (ItemExistsInPrevAdded){
        addItemsFromAlreadyAddedItems(newItem,true)
    } else {
        console.log(newItem)
        setalreadyAddedbillItems(previtems => [...previtems,newItem])
        addItemsFromAlreadyAddedItems(newItem,false)
    }
  };

I have a state “alreadyAddedbillItems” which is a array of objects ( item objects )
When a new item is added i check in this array first if the item (same id) already exists in this state variable or not
(if it is not then it means the item of this specific id is being added to bill for first time)
so the “else” block of the code gets executed ( which now actually adds this item to “alreadyAddedbillItems” so next time the “if” block is executed
All till now is working fine with if i try to add a item using input method (manually typing id )
But When i try to add a item by scanning the qr code it works fine for first time (means the else block does gets executed ) but the time i add item using the qr code again idk why it again goes to else block so i tried logging “alreadyAddedbillItems” but guess what it was empty idk why…

• Third Function (Last function)

const addItemsFromAlreadyAddedItems = async (Existingitem,bool) => {
        if(bool){
          const ExistingBillItem = billItems.find((item) => item.ItemId === Existingitem.ItemId)
          let ExistingBillItemNoDiscount = billItems.find((item) => item.ItemId === Existingitem.ItemId + "'")
          if (!ExistingBillItemNoDiscount){
            ExistingBillItemNoDiscount = {
              Quantity : 0,
            }
          }
          if (Existingitem.Quantity >= ExistingBillItem.Quantity 
            + ExistingBillItemNoDiscount.Quantity + 1){
            const discountQty = Existingitem.ItemsOnDiscount
            if (discountQty >= ExistingBillItem.Quantity + 1) { 
              setBillItems((previtems) =>
                previtems.map((item) =>
                  item.ItemId === ExistingBillItem.ItemId
                    ? { ...item, Quantity: item.Quantity + 1 }
                    : item
                )
              );
              toast.success("Item Added Succesfully first",{
                autoClose: 2000,
              });
            } else {
              const findNodiscountOne = billItems.find((item) => Existingitem.ItemId + "'" === item.ItemId)
              if (findNodiscountOne){
                setBillItems((previtems) =>
                  previtems.map((item) =>
                    item.ItemId === ExistingBillItem.ItemId + "'"
                      ? { ...item, Quantity: item.Quantity + 1 }
                      : item
                  )
                );
              } else {
                const BillItem = {
                  ItemId : Existingitem.ItemId + "'",
                  Itemname : Existingitem.Itemname,
                  Quantity : 1,
                  DiscountP: '0%',
                  price : Existingitem.price
                }
                setBillItems([
                  ...billItems,
                  BillItem
                ])
              }
              toast.success("Item Added Succesfully second",{
                autoClose: 2000,
              });
            }
            
          } else {
            toast.error("Not Enough Qty In Inventory" , {
              autoClose : 1000,
            });
          }
        } else {
          let tempItem = {
                ItemId : Existingitem.ItemId,
                Itemname : Existingitem.Itemname,
                Quantity : 1,
                DiscountP: Existingitem.DiscountP ? `${Existingitem.DiscountP}%` : '0%',
                price : Existingitem.price
          }
          setBillItems(prevItems => [...prevItems,tempItem])
          toast.success("Item Added Succesfully third",{
            autoClose: 2000,
          });
        }
  }

All functions gets executed in sequence first < second < third
(Everything works fine by adding the items though input method)
Full code – (https://pastecord.com/ulutifyzub.js)

i tried to see that if the “alreadyAddedbillItems” is even being updated or not
by using a useEffect having a dependency [alreadyAddedbillItems]

useEffect(() => {console.log(updated)},[alreadyAddedbillItems])

When using input method to add items it works fine means it just executed when i added the item for first time, and not if i added the same item again second time

-> Till now i was thinking ok seems like the “alreadyAddedbillItems” is not being updated but when i tried this it actally was being updated means this useeffect was executing but “alreadyAddedbillItems” was still logging empty in second function.

I have no idea why is this happening , please help me out in figuring out what’s the problem if u can
Thank You !