Would the Patch Be Quickly Merged Code review is one of the most timeconsuming and costly activities in modern software development. For the code submissions that can not be accepted by reviewers, developers need to remodify the code again. Developers desire to minimize the timecost that spends in the code review process. In some cases, a submission might be submitted many times and still not be accepted. The number of review times has serious implications for defect repairs and the progress of development. Therefore, a few recent studies focused on discussing factors that effect submission acceptance, while these prior studies did not try to predict submission acceptance or the number of review times. In this paper, we propose a novel method to predict the timecost in code review before a submission is accepted. Our approach uses a number of features, including review metafeatures, code modifying features and code coupling features, to better reflect code changes and review process. To examine the benefits of our method, we perform experiments on two large open source projects, namely Eclipse and OpenDaylight. Our results show that the proposed approach in the problem of predicting submission acceptance achieves an accuracy of 79.72%, 80.03% for Eclipse and OpenDaylight, respectively. For the prediction of review times ranges, our method achieves an accuracy of 66.42% and 60.42% for Eclipse and OpenDaylight, respectively.

Understanding predictive factors for merge conflicts Abstract   Context: Merge conflicts often occur when developers change the same code artifacts. Such conflicts might be frequent in practice, and resolving them might be costly and is an errorprone activity.  Objective: To minimize these problems by reducing merge conflicts, it is important to better understand how conflict occurrence is affected by technical and organizational factors.  Method: With that aim, we investigate seven factors related to modularity, size, and timing of developers contributions. To do so, we reproduce and analyze 73504 merge scenarios in GitHub repositories of Ruby and Python MVC projects.  Results: We find evidence that the likelihood of merge conflict occurrence significantly increases when contributions to be merged are not modular in the sense that they involve files from the same MVC slice (related model, view, and controller files). We also find bigger contributions involving more developers, commits, and changed files are more likely associated with merge conflicts. Regarding the timing factors, we observe contributions developed over longer periods of time are more likely associated with conflicts. No evaluated factor shows predictive power concerning both the number of merge conflicts and the number of files with conflicts.  Conclusion: Our results could be used to derive recommendations for development teams and merge conflict prediction models. Project management and assistive tools could benefit from these models.