Towards an I/O Conformance Testing Theory for Software Product Lines based on Modal Interface Automata

TL;DR

This paper extends I/O conformance testing to software product lines using Modal Interface Automata, enabling formal, compositional testing of variant behaviors with proven correctness.

Contribution

It introduces a modal-ioco relation based on MIA that supports variant derivation and guarantees correctness, advancing product line conformance testing theory.

Findings

Modal-ioco is preserved under MIA refinement.

Modal-ioco coincides with traditional ioco for derived variants.

A family-based conformance testing framework is established.

Abstract

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.