Most techniques proposed for regression testing are either black- or white-box techniques, i.e. they solely consider either the specification or implementation of a program. However, a combined technique can lead to significant savings in testing costs as some testing tasks need to be carried out once. Furthermore, the same test cases can cover both specification and implementation, reducing the total number of test cases.

This paper shows the application of class specification implementation graphs (CSIGs) in regression testing. The distinguishing feature of CSIGs from existing representations is that each method of a class is shown from two perspectives, namely the specification and implementation view. Moreover, a test suite reduction strategy has been incorporated to the CSIG construction algorithm to decrease the total number of test cases required. In this paper, we show how CSIGs can be combined with an existing test case selection algorithm for regression testing.