A GUI testing device may be configured to execute a testing state machine for interacting with a software application to generate an initial screen of a GUI. The GUI testing device may be configured to determine a current state in the testing state machine based upon a matching trigger target in the initial screen to a given state. The current state may include an operation, and the operation may associate with a trigger target to operate on. The trigger may include a source state, a destination state, and a trigger target. The operation may include a user input operation, and an operation trigger target. The GUI testing device may be configured to perform the operation on the matching trigger target in the initial screen to generate a next screen of the GUI, and advance from the current state to a next state based upon the trigger.