Class Firewall, Test Order, and Regression Testing of Object-Oriented Programs

Regression testing is an important activity in software maintenance. Although a number of existing research results have addressed the problems and solutions in regression testing of traditional programs, no research results have focused on the issues and solutions in regression testing of object-oriented programs. In this paper, we present a method for identifying the aaected classes when changes are made to an object-oriented program. An algorithm for generating a desirable order to test the aaected classes also is described. The basic model we use is an object relation graph, which depicts the inheritance, aggregation, and association relations that exist in the object-oriented program to be maintained. The test order nding algorithm can be applied to acyclic as well as cyclic object relation graphs. The results of this paper has been implemented and applied to testing of many example applications, including the InterViews library.