Impact of code review process smells on code smells

Abstract

The code review process is conducted by software teams with various motivations. Among other goals, code reviews act as a gatekeeper for software quality. Software quality comprises several aspects, maintainability (i.e., code quality) being one of them. In this study, we explore whether code review process quality (as evidenced by the presence of code review process smells) influences software maintainability (as evidenced by the presence of code smells). In other words, we investigate whether smells in the code review process are related to smells in the code that was reviewed by using correlation analysis. We augment our quantitative analysis with a focus group study to learn practitioners’ opinions. Contrary to our own intuition and that of the practitioners in our focus groups, we found that code review process smells have little to no correlation with the level of code smells. Further investigations revealed that the level of code smells neither increases nor decreases in 8 out of 10 code reviews, regardless of the quality of the code review. We identified multiple potential reasons behind the counter-intuitive results based on our focus group data. Furthermore, practitioners still believe that code reviews are helpful in improving software quality. Our results imply that the community should update our goals for code review practices and reevaluate those practices to align them with more relevant and modern realities.