Assessing and improving state-based class testing: A series of experiments

This paper describes an empirical investigation of the cost effectiveness of well-known state-based testing techniques for classes or clusters of classes that exhibit a state-dependent behavior. This is practically relevant as many object-oriented methodologies recommend modeling such components with statecharts which can then be used as a basis for testing. Our results, based on a series of three experiments, show that in most cases state-based techniques are not likely to be sufficient by themselves to catch most of the faults present in the code. Though useful, they need to be complemented with black-box, functional testing. We focus here on a particular technique, Category Partition. as this is the most commonly used and referenced black-box, functional testing technique. Two different oracle strategies have been applied for checking the success of test cases. One is a very precise oracle checking the concrete state of objects whereas the other one is based on the notion of state invariant (abstract states). Results show that there is a significant difference between them,