Predicting merge conflicts considering social and technical assets

Abstract

Concurrent contributions to a code base may introduce merge conflicts. Whereas merge conflicts are easy and common to introduce, resolving them is a difficult, time-consuming, and often error-prone task. Previous research concentrated on the emergence of merge conflicts considering technical assets in their analyses and often ignored the social perspective (e.g., developer roles). Our goal is to understand and predict merge conflicts considering social and technical assets. We devise three models for predicting merge conflicts based on common measures used by developers. The first model focuses on the social assets, the second on technical assets, and the third on technical and social assets. To evaluate our predictors, we report on a large-scale empirical study analyzing the histories of 66 real-world software systems. Specifically, we categorize developers into top or occasional contributors at project and merge-scenario level. We found that top contributors at project level and occasional contributors at merge-scenario level cause more merge conflicts than the other roles. Hence, the coordination of top contributors at project level and occasional contributors at merge-scenario level is a good starting point to minimize the occurrence of merge conflicts (especially because when these two developers work on the source branch, the chances of merge conflicts are 32.31%). Overall, we show that predicting merge conflicts incorporating developer roles is possible in practice with high accuracy (0.92) and recall (1.00) when combining technical and social assets, which is vital information to guide improvements on speculative merging techniques.