一句话：通过分析13个项目1162次重构与调查40名开发者，揭示实践中重构常伴随定制化修改且IDE支持不足。
文献为每种重构定义了标准代码修改，主流IDE也提供相应重构工具。但以往研究表明，开发者常避免使用这些工具，或修改甚至反转IDE自动重构的结果，从而被迫手动重构，既繁琐又易错，说明重构支持未必完全符合实践需求。为理解开发者如何定制重构修改，本文分析了来自13个软件项目的1162次重构，涉及超过10万处程序修改。结果显示，开发者会反复在标准修改之外应用额外的修改模式，即定制化重构模式；例如在观察到的Move Method实例中，80.77%存在定制化重构。作者还考察了主流IDE重构工具的特性，发现多数定制化模式未被充分支持。对40名开发者的调查进一步确认了这些定制化模式的相关性，并表明IDE重构支持亟需改进。研究结论是重构指南应更新以反映典型定制化，IDE构建者也可据此支持更灵活的重构应用，例如在将异常代码抽取为新方法时允许开发者选择由哪个方法处理方法异常。
Refactoring is a common software maintenance practice. The literature defines standard code modifications for each refactoring type and popular IDEs provide refactoring tools aiming to support these standard modifications. However, previous studies indicated that developers either frequently avoid using these tools or end up modifying and even reversing the code automatically refactored by IDEs. Thus, developers are forced to manually apply refactorings, which is cumbersome and error-prone. This means that refactoring support may not be entirely aligned with practical needs. The improvement of tooling support for refactoring in practice requires understanding in what ways developers tailor refactoring modifications. To address this issue, we conduct an analysis of 1,162 refactorings composed of more than 100k program modifications from 13 software projects. The results reveal that developers recurrently apply patterns of additional modifications along with the standard ones, from here on called patterns of customized refactorings. For instance, we found customized refactorings in 80.77% of the Move Method instances observed in the software projects. We also investigated the features of refactoring tools in popular IDEs and observed that most of the customization patterns are not fully supported by them. Additionally, to understand the relevance of these customizations, we conducted a survey with 40 developers about the most frequent customization patterns we found. Developers confirm the relevance of customization patterns and agree that improvements in IDE's refactoring support are needed. These observations highlight that refactoring guidelines must be updated to reflect typical refactoring customizations. Also, IDE builders can use our results as a basis to enable a more flexible application of automated refactorings. For example, developers should be able to choose which method must handle exceptions when extracting an exception code into a new method.
@inproceedings{OliveiraAGBRGF23,
title = {The untold story of code refactoring customizations in practice},
author = {Daniel Oliveira and Wesley K. G. Assunção and Alessandro Garcia and Ana Carla Bibiano and Márcio Ribeiro and Rohit Gheyi and Baldoino Fonseca},
booktitle = {ICSE},
year = {2023},
doi = {10.1109/icse48619.2023.00021}
}