Model-Based Testing

Compositionality, Decompositionality and Refinement in Input/Output Conformance Testing

“…Amongst others, Bauer et al use interface automata for compositional reasoning [4], whereas Alur et al characterize modal conformance as alternating simulation relation on interface automata [3], and Larsen et al have shown that both views on modal conformance coincide [14]. Based on our own previous work on modal I/O conformance testing [15,16], we present, to the best of our knowledge, the first comprehensive testing theory by means of a modal I/O conformance relation. More recently, Bujtor et al proposed testing relations on modal transition systems [9] based on (existing) test-suites, rather than being specification-based as our approach.…”

“…The example in Fig. 1 also explains why we consider Straces ♦ and after ♦ in property 2 (unlike modal-ioco in [15]). Otherwise, output e of q 4 in i would not be considered as mandatory output behavior because q 4 is not reachable via musttransitions.…”

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

“…The definitions of this section follow [20]. Figure 1: Sample LTS of a simple vending machine, adapted from [14]. I/O conformance requires any reaction of an implementation i to every possible environmental behavior σ to be checked against those of its specification s, even if no proper reaction for σ is actually specified by s. Hence, conformance testing is usually limited to positive testing, i. e., only considering behaviors being explicitly specified in s, i. e., contained in the suspension traces (Straces(s)) of s.…”

“…However, we propose to apply modal specifications to explicitly capture variability also within specifications, as being inherent to SPLs. We now define the foundations of modal input/output conformance [14] and introduce completion strategies for constructing input-enabled modal interface automata.…”

“…This way, a family-based I/O-conformance testing framework can be established, based on constraint-solving capabilities as used in [7] for product line model checking. In contrast, the approach proposed in [14], called mioco, adapts the key concepts of ioco to modal product line specifications where I/O-labeled MTS (IOMTS) are used as specifications of product lines under test. A corresponding family-based I/O-conformance testing theory can be built upon the notions of modal refinement and composition [12].…”