Model-based test driven development of the Tefkat model-transformation engine

Tefkat is an implementation of a rule- and pattern-based engine for the transformation of models defined using the Object Management Group's (OMG) Model-Driven Architecture (MDA). The process for the development of the engine included the concurrent development of a unit test suite for the engine. The test suite is constructed as a number of models, whose elements comprise the test cases, and which are passed to a test harness for processing. The paper discusses the difficulties and opportunities encountered in the process, and draws implications for the broader problem of testing in a model-driven environment, and of using models for testing.