Deriving Black-Box Test Cases from a State Transition Diagram (STD)

An Account class

Demonstration: An interactive account

A banking application has a simple ACCOUNT class. As shown in the following diagram, the ACCOUNT class has balance and account_number instance variable, and open, deposit, withdraw, display, show_balance and close methods.

The State Transition Diagram (STD)

Demonstration: The State Transition Diagram in action

The state transition diagram for the Account class is as follows :

Note: The ACCOUNT class in the state transition diagram has the additional methods, freeze, unfreeze and settle.

Note: Throughout this case study, the details of the ACCOUNT class will change slightly to highlight and hide