Anti-patterns in Modern Code Review: Symptoms and Prevalence

Abstract

Modern code review (MCR) is now broadly adopted as an established and effective software quality assurance practice, with an increasing number of open-source as well as commercial software projects identifying code review as a crucial practice. During the MCR process, developers review, provide constructive feedback, and/or critique each others' patches before a code change is merged into the codebase. Nevertheless, code review is basically a human task that involves technical, personal and social aspects. Existing literature hint the existence of poor reviewing practices i.e., anti-patterns, that may contribute to a tense reviewing culture, degradation of software quality, slow down integration, and may affect the overall sustainability of the project. To better understand these practices, we present in this paper the concept of Modern Code Review Anti-patterns (MCRA) and take a first step to define a catalog that enumerates common poor code review practices. In detail we explore and characterize MCRA symptoms, causes, and impacts. We also conduct a series of preliminary experiments to investigate the prevalence and co-occurrences of such anti-patterns on a random sample of 100 code reviews from various OpenStack projects.Index Terms-Modern code review, review anti-pattern

Understanding the Experience of Code Review: Misalignments, Attention, and Units of Analysis

“…In relation to the works listed above [1,4,14,15,18,21], our work has a stronger focus on the developer experience and to what extent the code review tools are supporting code review tasks. Our focus on experience is closer to the recent work by Chouchen et al [6] and Ebert et al [10].…”

“…Chouchen et al [6] present anti-patterns in code review gathered from reviewing the literature; confused reviews (e.g., reviewers ask questions about rational for a change), divergent reviews (e.g., no consensus in reviewer decision), low reviewer participation (e.g., few comments or lack of prompt feedback), shallow review (e.g., shallow comments on complex changes), and toxic review (e.g., comments with a negative sentiment). They manually inspect a sample of 100 code reviews and find a presence of all anti-patterns in the sample.…”

“…Empirical research consistently shows that modern (tool-supported) code reviews have a positive impact on software quality [15,16,18,19,23]. However, there is also evidence showing that code review requires a lot of effort [3,15,20], might not always be effective [8], can induce confusion [10], and can harbor toxic conversations [6] and bullying [4].…”

“…The report by Sadowski et al [18] includes causes of breakdown in the code review process leading to frustration, e.g., the tone and use of power in code review communication, or the topic of the review and whether the code review tool is the best place to conduct a design review. Related to these breakdowns, recent work by Chouchen et al [6] analyzed past studies on code review and presents five anti-patterns in code review; confused reviewers, divergent reviews, low review participation, shallow reviews, and toxic reviews. Delving deeper into confusion, recent work by Ebert et al [10] studies confusion in code review; reasons for it, the impact of it, and coping strategies.…”

“…The interviews were analyzed thematically [6] as an extension to an initial reading of the interview notes and transcripts [1].…”