Regression testing of GUIs

Although graphical user interfaces (GUIs) constitute a large part of the software being developed today and are typically created using rapid prototyping, there are no effective regression testing techniques for GUIs. The needs of GUI regression testing differ from those of traditional software. When the structure of a GUI is modified, test cases from the original GUI are either reusable or unusable on the modified GUI. Since GUI test case generation is expensive, our goal is to make the unusable test cases usable. The idea of reusing these unusable (a.k.a. obsolete) test cases has not been explored before. In this paper, we show that for GUIs, the unusability of a large number of test cases is a serious problem. We present a novel GUI regression testing technique that first automatically determines the usable and unusable test cases from a test suite after a GUI modification. It then determines which of the unusable test cases can be repaired so they can execute on the modified GUI. The last step is to repair the test cases. Our technique is integrated into a GUI testing framework that, given a test case, automatically executes it on the GUI. We implemented our regression testing technique and demonstrate for two case studies that our approach is effective in that many of the test cases can be repaired, and is practical in terms of its time performance.