一句话：通过挖掘 GitHub 上 305 个 fork 生态并实际移植测试用例，实证评估测试用例跨 fork 复用的可行性与收益。
社交编程平台上的 fork 使项目通过克隆并行演化，形成 fork 生态，但代码传播与同步零散，各项目质量不一、重复开发严重；测试用例往往未被其他 fork 复用，其跨项目可复用性尚不清楚。本文从 GitHub 挖掘 305 个 fork 生态（共 1,089 个项目）的测试用例数据集，通过人工审查可适用性、实际移植测试用例并分析不可适用原因，系统评估测试用例在 fork 项目间的复用潜力。研究给出了复用测试用例的收益（如发现缺陷）与挑战（如自动化代码移植与适用性判定），为在 fork 生态中复用测试用例以提升质量、可维护性与开发效率提供了实证依据。
Code is often reused to facilitate collaborative development, to create software variants, to experiment with new ideas, or to develop new features in isolation. Social-coding platforms, such as GitHub, enable enhanced code reuse with forking, pull requests, and cross-project traceability. With these concepts, forking has become a common strategy to reuse code by creating clones (i.e., forks) of projects. Thereby, forking establishes fork ecosystems of co-existing projects that are similar, but developed in parallel, often with rather sporadic code propagation and synchronization. Consequently, forked projects vary in quality and often involve redundant development efforts. Unfortunately, as we will show, many projects do not benefit from test cases created in other forks, even though those test cases could actually be reused to enhance the quality of other projects. We believe that reusing test cases—in addition to the implementation code—can improve software quality, software maintainability, and coding efficiency in fork ecosystems. While researchers have worked on test-case-reuse techniques, their potential to improve the quality of real fork ecosystems is unknown. To shed light on test-case reusability, we study to what extent test cases can be reused across forked projects. We mined a dataset of test cases from 305 fork ecosystems on GitHub—totaling 1,089 projects—and assessed the potential for reusing these test cases among the forked projects. By performing a manual inspection of the test cases' applicability, by transplanting the test cases, and by analyzing the causes of non-applicability, we contribute an understanding of the benefits (e.g., uncovering bugs) and of the challenges (e.g., automated code transplantation, deciding about applicability) of reusing test cases in fork ecosystems.
@inproceedings{MukelabaiDKB23,
title = {To Share, or Not to Share: Exploring Test-Case Reusability in Fork Ecosystems},
author = {Mukelabai Mukelabai and Christoph Derks and Jacob Krüger and Thorsten Berger},
booktitle = {ASE},
year = {2023},
doi = {10.1109/ase56229.2023.00191}
}