Event Listener Analysis and Symbolic Execution for Testing GUI Applications

Graphical User Interfaces (GUIs) are composed of virtual objects, widgets, which respond to events triggered by user actions. Therefore, test inputs for GUIs are event sequences that mimic user interaction. The nature of these sequences and the values for certain widgets, such as textboxes, causes a two-dimensional combinatorial explosion. In this paper we present Barad, a GUI testing framework that uniformly addresses event-flow and data-flow in GUI applications generating tests in the form of event sequences and data inputs. Barad tackles the two-dimensional combinatorial explosion by pruning regions of the event and data input space. For event sequence generation we consider only events with registered event listeners, thus pruning regions of the event input space. We introduce symbolic widgets which allow us to obtain an executable symbolic version of the GUI. By symbolically executing the chain of listeners registered for the events in a generated event sequence we obtain data inputs, thus pruning regions in the data input space. Barad generates fewer tests and improves branch and statement coverage compared to traditional GUI testing techniques.