static void Main()
        {
            var terminal = new PointOfSaleTerminal();

            terminal.SetPricing("A", 1.25m, 3, 3.00m);
            terminal.SetPricing("B", 4.25m, null, null);
            terminal.SetPricing("C", 1, 6, 5.00m);
            terminal.SetPricing("D", 0.75m, null, null);
            terminal.ScanProduct("A");
            terminal.ScanProduct("B");
            terminal.ScanProduct("C");
            terminal.ScanProduct("D");
            terminal.ScanProduct("A");
            terminal.ScanProduct("B");
            terminal.ScanProduct("A");
            var totalSum = terminal.CalculateTotal();

            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            terminal.ScanProduct("C");
            totalSum = terminal.CalculateTotal();

            terminal.ScanProduct("A");
            terminal.ScanProduct("B");
            terminal.ScanProduct("C");
            terminal.ScanProduct("D");
            totalSum = terminal.CalculateTotal();
        }
        public void SetPricing_ScanSingleUnitOfItem_CheckCalculatedPriceIsUnitPrice(string productName, decimal unitPrice, int bulkQuantity, decimal bulkPrice)
        {
            var terminal = new PointOfSaleTerminal();

            terminal.SetPricing(productName, unitPrice, bulkQuantity, bulkPrice);

            terminal.ScanProduct(productName);
            Assert.AreEqual(unitPrice, terminal.CalculateTotal(), "Total Price for the scanned item should be equal to its unit price");
        }
        public void DoNotSetBulkPricing_Scan10Items_CheckCalculatedPriceIsbasedOnUnitPrice(string productName, decimal unitPrice, int bulkQuantity, decimal bulkPrice)
        {
            var terminal = new PointOfSaleTerminal();

            terminal.SetPricing(productName, unitPrice, bulkQuantity, bulkPrice);

            for (var itemCount = 0; itemCount < 10; itemCount++)
            {
                terminal.ScanProduct(productName);
            }

            Assert.AreEqual(unitPrice * 10, terminal.CalculateTotal(), "Total Price for the scanned item should be equal to its ten times of its 10 times of unit price");
        }
        public void SetPricing_ScanBulkQuantityOfItem_CheckCalculatedPriceIsBulkPrice(string productName, decimal unitPrice, int bulkQuantity, decimal bulkPrice)
        {
            var terminal = new PointOfSaleTerminal();

            terminal.SetPricing(productName, unitPrice, bulkQuantity, bulkPrice);

            for (var itemCount = 0; itemCount < bulkQuantity; itemCount++)
            {
                terminal.ScanProduct(productName);
            }

            Assert.AreEqual(bulkPrice, terminal.CalculateTotal(), "Total Price for the scanned item should be equal to its bulk price");
        }
        public void ScanSomeProducts_CalculatePrice_VerifyUnitPriceAndBulkPriceAppliedAccordingly(string[] listOfItemsToBeScanned, decimal expectedTotalSum)
        {
            var terminal = new PointOfSaleTerminal();

            terminal.SetPricing("A", 1.25m, 3, 3.00m);
            terminal.SetPricing("B", 4.25m, null, null);
            terminal.SetPricing("C", 1, 6, 5.00m);
            terminal.SetPricing("D", 0.75m, null, null);

            foreach (var item in listOfItemsToBeScanned)
            {
                terminal.ScanProduct(item);
            }

            Assert.AreEqual(expectedTotalSum, terminal.CalculateTotal(), "Calculated price should be based on bulk price and unit price specified");
        }