Circumventing Refactoring Masking using Fine-Grained Change Recording

Today, refactoring reconstruction techniques are snapshot based: they compare two revisions from a source code management system and calculate the shortest path of edit operations to go from the one to the other. An inherent risk with snapshot-based approaches is that a refactoring may be concealed by later edit operations acting on the same source code entity, a phenomenon we call refactoring masking. In this paper, we performed an experiment to find out at which point refactoring masking occurs and confirmed that a snapshot-based technique misses refactorings when several edit operations are performed on the same source code entity. We present a way of reconstructing refactorings using fine grained changes that are recorded live from an integrated development environment and demonstrate on two cases PMD and Cruisecontrol that our approach is more accurate in a significant number of situations than the state-of-the-art snapshot-based technique RefFinder.