GitHub Actions: The Impact on the Pull Request Process

Automated tools are frequently used in social coding repositories to perform repetitive activities that are part of the distributed software development process. Recently, GitHub introduced GitHub Actions, a feature providing automated workflows for repository maintainers. Understanding and anticipating the effects of adopting such kind of technology is important for planning and management. Our research investigates how projects use GitHub Actions, what the communities discuss about them, and how activity indicators change after their adoption. Our results indicate that a considerable number of projects adopt GitHub Actions (almost 30% of our sample) and that developers frequently ask for help with them. Our findings also suggest that the adoption of GitHub Actions leads to more rejections of pull requests (PRs), more communication in accepted PRs and less in rejected PRs, fewer commits in accepted PRs and more in rejected PRs, and more time to accept a PR. We found similar results in the Utility Actions but we found fewer rejected PRs for the Code Quality Actions. Our results are especially relevant for practitioners to consider these effects when adopting GitHub Actions on their projects.