Abstract: In a preferred embodiment, the present invention provides an improved method and system for testing a graphical user interface program. The preferred embodiment provides improved performance over prior methods because it decouples the testing of an program's engine component from the testing of its GUI component. The preferred method begins the testing process by invoking test functions that send data to the program's engine component. The data simulates user action on the graphical user interface of the program. In response to receiving the data, the engine component processes the simulated user action as if it had been sent from the graphical user interface component. The preferred method captures the results of this processing and uses the results to determine whether the engine component is performing properly.