public void Quantity_NegativeTest()
        {
            RetailStore rStore = new RetailStore(23456, "21-Jan-2020", 34567, "John Wick from Paris", "9191919191", 9998, "Apple Watch Series 4", 1, 0);
            bool        TestPass;

            if (rStore.QuantityPurchased > 0)
            {
                TestPass = true;
                Decimal Expenditure          = rStore.Total_Shopping_expense();
                String  Expenditure_Currency = String.Format("{0:C}", Expenditure);
                Console.WriteLine("Total Shopping Expense is : " + Expenditure_Currency);
                Console.WriteLine(rStore);
                Console.WriteLine("The Quantity is : " + rStore.QuantityPurchased);
            }

            else
            {
                Console.WriteLine("Quantity is Invalid!!!");
                TestPass = false;
            }

            Assert.IsFalse(TestPass);
        }
        public void ReceiptNumberPositiveTest()
        {
            RetailStore rStore = new RetailStore(23456, "21-Jan-2020", 34567, "John Wick from Paris", "9191919191", 3131, "Apple Watch Series 4", 455, 3);
            bool        TestPass;

            if (rStore.ReceiptNumber > 0)
            {
                TestPass = true;
                Decimal Expenditure          = rStore.Total_Shopping_expense();
                String  Expenditure_Currency = String.Format("{0:C}", Expenditure);
                Console.WriteLine("Total Shopping Expense is : " + Expenditure_Currency);
                Console.WriteLine(rStore);
                Console.WriteLine("The receipt number is : " + rStore.ReceiptNumber);
            }

            else
            {
                Console.WriteLine("Receipt Number is Invalid!!!");
                TestPass = false;
            }

            Assert.IsTrue(TestPass);
        }
        public void UnitNumber_NegativeTest2()
        {
            RetailStore rStore = new RetailStore(23456, "21-Jan-2020", 34567, "John Wick from Paris", "9191919191", 9998, "Apple Watch Series 4", 9999, 3);
            bool        TestPass;

            if (rStore.UnitPrice > 0 && rStore.UnitPrice < 9999)
            {
                TestPass = true;
                Decimal Expenditure          = rStore.Total_Shopping_expense();
                String  Expenditure_Currency = String.Format("{0:C}", Expenditure);
                Console.WriteLine("Total Shopping Expense is : " + Expenditure_Currency);
                Console.WriteLine(rStore);
                Console.WriteLine("The Unit Price is : " + rStore.UnitPrice);
            }

            else
            {
                Console.WriteLine("Unit Price is Invalid!!!");
                TestPass = false;
            }

            Assert.IsFalse(TestPass);
        }