Software Product Line (SPL) techniques are widely used to represent variability and commonality in reusable software assets. Similarly, model transformations are also software assets and can be reused with the same techniques. However, their applicability in the model transformations domain demands an extra effort to test the generated/adapted assets. Automated test cases should consider isolated transformations and also their combined use in a model transformation chain, that can vary according to different needs in software projects, e.g. libraries and frameworks. In order to facilitate the specification of automated test cases, this paper presents a JUnit extension to support unit and integration tests that execute dynamic SPL-based model transformation chains.