Testing polymorphic behavior of framework components

An object-oriented framework is often the key component in building products for a given application area. Given such a framework, an application developer needs only to provide definitions suited to the needs of his or her product for the hook methods. With appropriate initializations, the calls to the hook methods made by the template methods defined in the framework will then be dispatched to the definitions provided by the developer, thus customizing the behavior of the template methods. Specifying and testing such a framework, in particular, specifying and testing its polymorphic behavior that enables such customization, presents some challenges. We discuss these and develop ways to address them.