Towards Generating the Rationale for Code Changes

Commit messages are essential to understand changes in software projects, providing a way for developers to communicate code evolution. Generating effective commit messages that explain the rationale behind changes is a challenging and timeconsuming task. While previous research has shown success in automating straightforward commit messages (e.g., “add README”), our study explores a more complex task: generating rationale explanations for code changes. We developed a method to identify rationale sentences in commit messages and compiled a dataset of 45,945 commits with their corresponding rationales. A pre-trained model was trained on this dataset to generate rationale explanations. While the approach we engineered for the extraction of rationale from commit messages exhibited a 75 % precision, the model trained to generate the rationale only worked in a minority of cases. Our findings highlight the difficulty of the tackled task and the need for additional research in the area. We release our dataset and code to foster the investigation of this problem.