Towards an I/O Conformance Testing Theory for Software Product Lines based on Modal Interface Automata
This work addresses testing challenges for software product lines, offering a formal framework to ensure conformance across implementation variants, though it appears incremental as it builds on existing ioco and MIA theories.
The paper adapts input/output conformance (ioco) testing principles to software product lines using Modal Interface Automata (MIA) to handle behavioral variability, proving that the resulting modal-ioco relation is correct and coincides with traditional ioco for all derivable variants.
We present an adaptation of input/output conformance (ioco) testing principles to families of similar implementation variants as appearing in product line engineering. Our proposed product line testing theory relies on Modal Interface Automata (MIA) as behavioral specification formalism. MIA enrich I/O-labeled transition systems with may/must modalities to distinguish mandatory from optional behavior, thus providing a semantic notion of intrinsic behavioral variability. In particular, MIA constitute a restricted, yet fully expressive subclass of I/O-labeled modal transition systems, guaranteeing desirable refinement and compositionality properties. The resulting modal-ioco relation defined on MIA is preserved under MIA refinement, which serves as variant derivation mechanism in our product line testing theory. As a result, modal-ioco is proven correct in the sense that it coincides with traditional ioco to hold for every derivable implementation variant. Based on this result, a family-based product line conformance testing framework can be established.