Testing OO Software

1
Testing OO Software

• Encapsulation means modeling and storing with an
  object the parts and the operations.
• Interactions become implicit in code.
• Makes difficult to understand interactions and to
  prepare test cases for them.

2
Testing OO Software

• Perry/KaiserAdequate Testing and Object-Oriented
  Programming
• Retest everything when context changes

3
Testing OO Software

• Smith/Robson Object-Oriented Programming - The
  Problems of Validation
• Quality of a collection of classes
• Test not only for correctness but quality of code
• Code written with a consistent method (such as
  the Demeter Method) should have a higher quality
  than ad-hoc written code

4
Testing OO Software

• Wilde/Huitt Maintenance Support for
  Object-Oriented Programs
• Law of Demeter
• Propagation patterns
• Abstracting propagation patterns

5
Small methods problem of OO

• In 3 large scale studies 50 of methods are less
  than 2 C statements or 4 Smalltalk statements
• Law of Demeter connection

6
Testing OO Software

• Robert Binder Design for Testability in
  Object-Oriented Systems
• Separation of concerns
• avoid entwined capabilities, makes testing easier
• user interface capabilities should not be
  entwined with basic functions
• Law of Demeter
• Demeter Compliance reduces number of interfaces?

7
Encapsulation
8
Two definitions of AOP

• NU definition Collaborating units, loosely
  coupled, each unit enhancing other units, change
  in one minimal changes in others cross cutting
• Xerox PARC new an aspect is modular unit that
  cross-cuts other modular units. Old Aspect what
  is not a component