Identifying Candidate Classes for Unit Testing Using Deep Learning Classifiers: An Empirical Validation

This paper aims at investigating the use of deep learning to suggest (prioritize) classes to be tested rigorously during unit testing of object-oriented systems. We relied on software unit testing information history and source code metrics. We conducted an empirical study using data collected from two Apache open-source Java software systems (POI and ANT). For each software system, we extracted the source code of five different versions. For each version, we collected various metrics from the source code of the Java classes. Then, for all software classes, we extracted testing coverage measures at instruction and method levels of granularity. We used the existing JUnit test cases developed for these systems. Based on the different datasets we collected, we trained several deep neural network models. We validated the obtained classifiers using four validation techniques: (1) CV: Cross Version validation, (2) CPV: Combined Previous Version validation, (3) CSPV: Combined System and Previous Version validation, and (4) LOSO: Leave One System Out validation. The obtained results in terms of classifiers’ performance vary between 70% and 80% of accuracy and strongly support the viability of our approach.