Using Animations to Understand Commits

Commits, which log the changes that have been performed by developers, are the central mechanism to drive the evolution of software systems. Understanding the intricacies of commits can be a nontrivial endeavour. Firstly, this is due to the diff-based textual nature of how versioning systems record the changes. Moreover, a commit can involve several files and pertain to various, overlapping tasks that the developer was tackling, which can lead to difficult to understand “tangled commits”. Furthermore, often commit messages lack quality. The only mechanism to really understand the changes performed in a commit is given by text-based “diff” representations, which are cumbersome to use. We present an approach, based on interactive animated visualizations, to facilitate the comprehension of the changes tracked by commits. To validate the approach, we implemented an interactive visual analytics tool which allows developers to dissect a commit in its constituent parts and observe, through the animations supported by our tool, the specifics of each change. We illustrate our approach with examples, and report on our findings and insights.