Coverage criteria for GUI testing

The widespread recognition of the usefulness of graphical user interfaces (GUIs) has established their importance as critical components of todays software. GUIs have characteristics different from traditional software, and conventional testing techniques do not apply directly to GUI software. This papers focus is on coverage criteria for GUIs, an important tool in testing. We present new coverage criteria that may be employed to help determine whether a GUI has been adequately tested. These coverage criteria use events and event sequences to specify a measure of test adequacy. Since the total number of permutations of event sequences in any non-trivial GUI is extremely large, the GUIs hierarchical structure is exploited to identify the important event sequences to be tested. The GUIs hierarchy is decomposed into GUI components each of which is used as a basic unit of testing. A new representation of a GUI component, called an event-flow graph, identifies the interaction of events within a component and intra-component criteria are used to evaluate the adequacy of tests on these events. The hierarchical relationship among components is represented by an integration tree and inter-component coverage criteria are used to evaluate the adequacy of test sequences that cross components. Algorithms are described to construct event-flow graphs and an integration tree for a given GUI, and to evaluate the coverage of a given test suite with respect to the new coverage criteria. A case study illustrates an important correlation between event-based coverage of a GUI and statement coverage of the softwares underlying code. Partially supported by the Andrew Mellon Pre-doctoral Fellowship. Effective Aug 1, 2001: Department of Computer Science, University of Maryland. atif@cs.um...