Selecting Regression Tests for Object-Oriented Software

Regression testing is an important but expensive software maintenance activity aimed at providing con-dence in modiied software. Selective retest methods reduce the cost of regression testing by selecting tests for a modiied program from a previously existing test suite. Many researchers have addressed the selective retest problem for procedural-language software, but few have addressed the problem for object-oriented software. In this paper, we present a new technique for selective retest, that handles object-oriented software. Our algorithm constructs dependence graphs for classes and applications programs, and uses these graphs to determine which tests in an existing test suite can cause a modiied class or program to produce diierent output than the original. Unlike previous selective retest techniques, our method applies to modiied and derived classes, as well as to applications programs that use modiied classes. Our technique is strictly code-based, and makes no assumptions about methods used to specify or test the software initially.