Dynamic Testing of GUI Exercises in Headless Environments

Testing Graphical User Interface applications in non-graphical environments is challenging, especially for auto-graders in large-scale programming courses, where traditional approaches often depend on a graphical operating system. This paper presents a headless testing approach that simulates user interactions and verifies application state. A reference implementation demonstrates that interactive applications can be assessed reliably in headless settings. The approach ran in a large-scale introductory programming course, assessing 1,020 submissions without a graphical subsystem. A case study confirms the system meets key requirements and delivers reproducible, scalable, and pedagogically valuable feedback.