Regression testing of GUI event interactions

Graphics user interface (GUI) design is an expected part of almost every contemporary software or computer project, and yet the testing is usually approached in an ad hoc fashion. The reason GUI testing is different and difficult is that the input is interactive whereas the output may be graphical or may be an event. An especially serious problem occurs in maintenance where changes are made to the GUI interface, and the maintenance engineer does not have a sufficient understanding of how the GUI software was designed; in this case, an automated GUI testing method is needed. The paper identifies both static and dynamic event interactions in a GUI, and shows how automated regression tests can be generated to test these interactions. It is shown how Latin Squares can be used for this automated test design, where Latin Squares techniques are borrowed from statistical experimental design. Three methods are compared: brute force test generation, random test generation and the use of Latin Squares, comparing the number of tests required to cover specified GUI event interactions in each case