Evolution of GitHub Action Workflows

Abstract

GitHub Actions are an event-driven tool to automatically respond to particular GitHub events. Typical events are receiving new pull requests or publishing a software release. Despite the massive and quick adoption of GitHub Actions, little is known about the incremental construction of GitHub Actions workflow by practitioners. This paper presents the result of a manual inspection of 222 commits of GitHub Actions workflows obtained from 10 popular open-source repositories. Our hierarchical taxonomy, obtained by systematically categorizing and tagging workflow modifications, reveals 11 types of modifications and presents opportunities for improvement in the way workflows are built and edited. In particular, our results highlight the need for adequate tooling to support refactoring, debugging and code editing of GitHub Actions workflows.