Interactively Decomposing Composite Changes to Support Code Review and Regression Testing

Developers often address multiple development issues to make composite code changes, as opposed to atomic changes that address one single issue. Investigating and testing such code changes is a tedious and error-prone process for developers. To address the problem, this paper presents a technique, called CHGCUTTER, for (1) interactively decomposing composite changes into atomic changes, (2) building related change subsets using program dependence relationships without syntactic violation, and (3) safely selecting only related test cases from the test suite to reduce the time to conduct regression testing. In the evaluation, CHGCUTTER analyzes 28 composite changes in four open source projects. It identifies related change subsets with 95.7% accuracy, and it selects test cases affected by these changes with 89.0% accuracy. Our results show that CHGCUTTER should help developers effectively inspect changes and validate modified applications during development.