There are 3 basic conditions we need to check

1. Syntactically Incorrect Inputs
2. UPC does not exist
3. A successful transaction

We must prepare the data in the system to meet the following conditions:

1. User1 enters cashier interface
   INPUT
   • We then login to the system as user1, and accesses the cashier interface, and enters asfasfj23523 in the Cash Given field.
   Expected Result
   • An error would result with the system telling the user that an invalid input was entered. The cursor will remain active in the Cash Given field.

   Similarly, this test can be repeated on various combinations of syntactically incorrect inputs being entered; first isolated cases

   UPC -- has to contain only numeric characters

   then various combinations of incorrect syntax being used to check if each error will be caught by the system

2. There does not exist an item with a UPC of 12345
   INPUT
   • We then login to the system as user1, and accesses the cashier interface
   • We enter 12345 in the UPC field.
   Expected Result
   • An error message stating that the given UPC does not exists in the database, the field is refreshed and the user prompted to re-enter a VALID UPC.

3. A successful transaction. There exists an item with UPC 123 and sales_price of 2.00.
   INPUT
   • We then login to the system as user1, and accesses the cashier interface.
   • We enter 123 into the UPC field and 12.00 in the Cash Given field, and a quantity of 2.
   Expected Result
   • Upon completion of this form, the inventory for the item associated with the UPC will be decremented by 2, the Amount Owing should be -8.00, the Change should be 8.00 and the receipt should show that the item with UPC 123 has been purchased in a quantity of 2. The form is reset (except for the receipt, Cash_Given, Change, and Amount Owing output fields).

Main Page