On the Quality of Identifiers in Test Code

Meaningful, expressive identifiers in source code can enhance the readability and reduce comprehension efforts. Over the past years, researchers have devoted considerable effort to understanding and improving the naming quality of identifiers in source code. However, little attention has been given to test code, an important resource during program comprehension activities. To better grasp identifier quality in test code, we conducted a survey involving manually written and automatically generated test cases from ten open source software projects. The survey results indicate that test cases contain low quality identifiers, including the manually written ones, and that the quality of identifiers is lower in test code than in production code. We also investigated the use of three state-of-the-art rename refactoring recommenders for improving test code identifiers. The analysis highlights their limitations when applied to test code and supports mapping out a research agenda for future work in the area.