Tractable Model Transformation Testing

Model transformation (MT) testing is gaining interest as the size and complexity of MTs grows. In general it is very difficult and expensive (time and computational complexity-wise) to validate in full the correctness of a MT. This paper presents a MT testing approach based on the concept of Tract, which is a generalization of the concept of Model Transformation Contract. A Tract defines a set of constraints on the source and target metamodels, a set of source-target constraints, and a tract test suite, i.e., a collection of source models satisfying the source constraints. We automatically generate input test suite models, which are then transformed into output models by the transformation under test, and the results checked with the USE tool (UML-based Specification Environment) against the constraints defined for the transformation. We show the different kinds of tests that can be conducted over a MT using this automated process, and the kinds of problems it can help uncovering.