1. Dataflow Testing, Object-Oriented
Software Testing
Dataflow Testing,
Object-Oriented

2. Data flow coverage Def x is a node where x is defined (given a value)
Use x is a node where the value of x is used in an expression or a decision
C use is in a computation
P use is in a decision (predicate)
A def-free path is a path from a definition to a use that does not include another definition of that variable.

3. dcu - from every def to a c-use
c-use (computation)
if a variable is defined in node A and there are computational uses in node B and D, the dcu coverages requires an def-free path segment of either ABC or ACD

4. dpu - from every def to a p-use
p-use (predicate)
if a variable is defined in node A and it is used in a decision in C, the dpu coverage requires two def-free paths, one with segment of A...CD and one with A...CE

5. du - from every def to every use
if a variable is defined in node A and there are computational uses in node B and D, the du coverage requires a def-free path from node A to node B and a def-free path from node A to node D

6. TTYP task
Generate test case sets for triangle problem
dpu
dcu du

7. Object-oriented Software Testing
Object-oriented testing
Pressman pp ,
SOS ch 13

8. Quotes
“It seems likely that more, not less testing will be needed to obtain high reliability in object-oriented systems” Binder (in Pressman)

9. Inheritance When do we need to retest the base class?
When can we assume that the base class has already been tested?

10. Dynamic Binding When do we have to be concerned with dynamic bindings?
virtual functions

11. Concerns about OO Testing
Functional testing seems just as relevant to oo software as to traditional software
Random and operational testing seem relevant to oo software
Structural testing, C0 and C1, doesn’t seem effective for oo software, except ...

12. Coverage of functions Every function should be called at least once
Overloaded functions need to have every version executed

13. Coverage of function calls
Every MM pair (Method-message) should be executed.
that is, every call to a method from a method should be executed
if a function has more than one call to another method, all calls need to executed

14. Coverage of States
An alternative view of testing is based on the states of a process
Testing coverage can be
every state
every transition
every pair of transitions
etc.

15. Data Flow coverage
Can we apply data flow coverage to object oriented software
Def’s are often in one method, use in another

16. Schedule Thurs, Apr 13 Tues, Apr 18 Thurs, Apr 20
Reliability - SOS
PLQ
Tues, Apr 18
Finish reliability, SQA task
Thurs, Apr 20
Make-up exam for OCL