An exploratory study of the impact of software changeability

Antipatterns are poor design choices that make object-oriented systems hard to maintain by developers. In this study, we investigate if classes that participate in antipatterns are more change-prone than classes that do not. Specifically, we test the general hypothesis: classes belonging to antipatterns are not more likely than other classes to undergo changes, to be impacted when fixing issues posted in issue- tracking systems, and in particular to unhandled exceptions-related issues - a crucial problem for any software system. We detect 11 antipatterns in 13 releases of Eclipse and study the relations between classes involved in these antipatterns and classes change-, issue-, and unhandled exception-proneness. We show that, in almost all releases of Eclipse, classes with antipatterns are more change-, issue-, and unhandled-exception-prone than others. These results justify previous work on the specification and detection of antipatterns and could help focusing quality assurance and testing activities.