What Do We Know About Readability of Test Code? - A Systematic Mapping Study

The readability of software code is a key success criterion for understanding and maintaining software systems and tests. In industry practice, a limited number of guidelines aim for improving and assessing the readability of software (test) code. Although several studies focus on investigating the readability of software code, we observed limited research work that focuses on the readability of software test code. In this paper we focus on systematically investigating the characteristics, factors, and assessment criteria that have an impact on the readability of test code. We build on a Systematic Mapping Study (SMS) to identify key characteristics, factors, and assessment criteria that have an impact on test code readability, legibility, and understandability to support and improve maintenance tasks. The result set includes 16 studies for further analysis. The majority of publications focuses on readability investigations of automatically generated test code (88%), often evaluated with surveys to access the readability of test code (44 %). Although several approaches aim at assessing the readability with focus on isolated factors, a combination of different readability aspects within an assessment framework can help to better assess and justify the readability of test code with focus on improving software and system test maintenance.