Recommending Move Method refactorings using dependency sets

Abstract

Methods implemented in incorrect classes are common bad smells in object-oriented systems, especially in the case of systems maintained and evolved for years. To tackle this design flaw, we propose a novel approach that recommends Move Method refactorings based on the set of static dependencies established by a method. More specifically, our approach compares the similarity of the dependencies established by a source method with the dependencies established by the methods in possible target classes. We evaluated our approach using systems from a compiled version of the Qualitas Corpus. We report that our approach provides an average precision of 60.63% and an average recall of 81.07%. Such results are, respectively, 129% and 49% better than the results achieved by JDeodorant, a well-known move method recommendation system.