A technique for the selective revalidation of OO software

The object-orientated paradigm provides the power for software development but at the same time introduces some brand new problems. One of these problems is that the relationships among classes are more complex and difficult to identify than those in the traditional paradigm. This problem becomes a major obstacle for regression testing of OO software, in which the relationships among classes as well as those between test cases and classes, must be determined a priori. In this paper we propose a new method to select only a fraction of the test cases from the entire test suite to revalidate an OO software system. This method is based on the concepts of class firewall and of marking all the classes ‘touched’ by a test case. From the class firewall, we can identify all of the affected classes after a new version of software is released. Together with the markings, we can also identify all the test cases in the test suite that need to be retested after the software change. A step-by-step process is proposed to identify the relationships between classes and test cases, compute the class firewall, and select only the appropriate test cases for retesting. © 1997 John Wiley & Sons, Ltd.