On the Investigation of Exception Pull Request Characteristics: Exploring the Apache Ecosystem

Robustness is critical for ensuring that software functions correctly under adverse conditions. Exception-handling mechanisms in programming languages enable developers to deal with these adverse conditions. However, implementing exception-related code can present significant challenges to developers. We investigated exception-related code contributions across Java projects in the Apache ecosystem. We analyzed exception-related pull requests (exception-PRs), which were detected using a validated heuristic. We produced a comprehensive dataset of 988 exception-PRs. We observed no statistically significant differences in complexity metrics between exception-PRs and non-exception-PRs. We also found no significant differences in developers' behavior metrics, indicating consistent engagement regardless of whether the pull request addressed exception-related code. A manual analysis revealed that most exception-PRs focused on system improvements rather than bug fixes, suggesting proactive efforts to enhance software robustness. Moreover, the most frequently addressed aspects of exceptional code in these exception-PRs were: (i) the external representation of adverse situations to end-users (more than 40% of the PRs) and (ii) the implementation of effective error-handling actions (nearly 35% of the PRs) to promote program recoverability. Interestingly, a significant proportion of exception-PRs simultaneously addressed multiple aspects. By understanding the nature and characteristics of exception-PRs, we expect to better support developers in managing erroneous conditions and improving software robustness.