Code readability is fundamental to software quality and maintainability. Poor readability extends development time, increases bug-inducing risks, and contributes to technical debt. With the rapid advancement of Large Language Models, AI agent-based approaches have emerged as a promising paradigm for automated refactoring, capable of decomposing complex tasks through autonomous planning and execution. While prior studies have examined refactoring by AI agents, these analyses cover all forms of refactoring, including performance optimization and structural improvement. As a result, the extent to which AI agent-based refactoring specifically improves code readability remains unclear.

Fuzzing has become a popular technique for automatically detecting vulnerabilities and bugs by generating unexpected inputs. In recent years, the fuzzing process has been integrated into continuous integration workflows (i.e., continuous fuzzing), enabling short and frequent testing cycles. Despite its widespread adoption, prior research has not examined whether the effectiveness of continuous fuzzing varies across programming languages.

Agentic Coding, powered by autonomous agents such as GitHub Copilot and Cursor, enables developers to generate code, tests, and pull requests from natural language instructions alone. While this accelerates implementation, it produces larger volumes of code per pull request, shifting the burden from implementers to reviewers. In practice, a notable portion of AI-generated code is eventually deleted during review, yet reviewers must still examine such code before deciding to remove it. No prior work has explored methods to help reviewers efficiently identify code that will be removed.

Agent-based coding tools have transformed software development practices. Unlike prompt-based approaches that require developers to manually integrate generated code, these agent-based tools autonomously interact with repositories to create, modify, and execute code, including test generation. While many developers have adopted agent-based coding tools, little is known about how these tools generate tests in real-world development scenarios or how AI-generated tests compare to human-written ones.

Modern software development heavily relies on third-party dependencies to reduce workload and improve developer productivity. Given the vast number of dependencies available and the ease of including them in projects, some introduced dependencies are never used, leading to bloated software, longer build times, and increased network bandwidth usage. While several previous studies have examined the prevalence of unused dependencies and their impact on security, it remains unclear how these dependencies are introduced and removed in software projects. This study aims to answer this question through an empirical study involving 3,020 release versions of 417 Java projects. Our analysis shows that unused packages are common in most projects ($52 \%$ of projects), but few releases (9%) introduce new unused dependencies. Among those resolved unused dependencies, $59 \%$ of them were removed and $41 \%$ were used in later versions. Our findings highlight that not all unused dependencies should be removed in practice.

In this paper, we present a collection of Modern Code Review data for five open source projects. The data showcases mined data from both an integrated peer review system and source code repositories. We present an easy-to-use and richer data structure to retrieve the (a) People, (b) Process, and (c) Product aspects of the peer review. This paper presents the extraction methodology, the dataset structure, and a collection of database dumps.

In recent times, gamification has become a popular technique to aid online communities stimulate active member participation. Gamification promotes a reward-driven approach, usually measured by response-time. Possible concerns of gamification could a trade-off between speedy over quality responses. Conversely, bias toward easier question selection for maximum reward may exist. In this study, we analyze the distribution gamification-influenced tendencies on the Q&A Stack Overflow online community. In addition, we define some gamification-influenced metrics related to response time to a question post. We carried experiments of a four-month period analyzing 101,291 members posts. Over this period, we determined a Rapid Response time of 327 seconds (5.45 minutes). Key findings suggest that around 92% of SO members have fewer rapid responses that non-rapid responses. Accepted answers have no clear relationship with rapid responses. However, we did find that rapid responses significantly contain tags that did not follow their usual tagging tendencies.

Software code review is a well-established software quality practice. Recently, Modern Code Review (MCR) has been widely adopted in both open source and proprietary projects. To evaluate the impact that characteristics of MCR practices have on software quality, this paper comparatively studies MCR practices in defective and clean source code files. We investigate defective files along two perspectives: 1) files that will eventually have defects (i.e., Future-defective files) and 2) files that have historically been defective (i.e., Risky files). Through an empirical study of 11,736 reviews of changes to 24,486 files from the Qt open source project, we find that both future-defective files and risky files tend to be reviewed less rigorously than their clean counterparts. We also find that the concerns addressed during the code reviews of both defective and clean files tend to enhance evolvability, i.e., Ease future maintenance (like documentation), rather than focus on functional issues (like incorrect program logic). Our findings suggest that although functionality concerns are rarely addressed during code review, the rigor of the reviewing process that is applied to a source code file throughout a development cycle shares a link with its defect proneness.

In the research of Mining Software Repositories, code repository is one of the core source since it contains the product of software development. Code repository stores the versions of files, and makes it possible to browse the histories of files, such as modification dates, authors, messages, etc. Although such rich information of file histories is easily available, extracting the histories of methods, which are elements of source code files, is not easy from general code repositories. To tackle this difficulty, we have developed Historage, a fine-grained version control system. Historage repository is a Git repository which is built upon original Git repository. Therefore, similar mining techniques for general Git repositories are applicable to Historage repositories. Kataribe is a hosting service of Historage repositories, which enables researchers and developers to browse method histories on the web and clone Historage repositories to local. The Kataribe project aims to maintain and expand the datasets and features.

We present four datasets that are focused on the general roles of OSS peer review members. With data mined from both an integrated peer review system and code source repositories, our rich datasets comprise of peer review data that was automatically recorded. Using the Android project as a case study, we describe our extraction methodology, the datasets and their application used for three separate studies. Our datasets are available online at http://sdlab.naist.jp/reviewmining/.