In medio stat virtus: Extract class refactoring through nash equilibria

Abstract

Extract Class refactoring (ECR) is used to divide large classes with low cohesion into smaller, more cohesive classes. However, splitting a class might result in increased coupling in the system due to new dependencies between the extracted classes. Thus, ECR requires that a software engineer identifies a trade off between cohesion and coupling. Such a trade off may be difficult to identify manually because of the high complexity of the class to be refactored. In this paper, we present an approach based on game theory to identify refactoring solutions that provide a compromise between the desired increment in cohesion and the undesired increment in coupling. The results of an empirical evaluation indicate that the approach identifies meaningful ECRs from a developer's point-of-view.