Arnaldo Vieira Moura

Adilson Luiz Bonifacio, Arnaldo Vieira Moura

Testing on reactive systems is a well-known laborious activity on software development due to their asynchronous interaction with the environment. In this setting model based testing has been employed when checking conformance and generating test suites of such systems using labeled transition system as a formalism as well as the classical ioco conformance relation. In this work we turn to a more complex scenario where the target systems have an auxiliary memory, a stack. We then studied a more powerful model, the Visibly Pushdown Labeled Transition System (VPTS), its variant Input/Output VPTS (IOVPTS), its associated model Visibly Pushdown Automaton (VPA), and aspects of conformance testing and test suite generation. This scenario is much more challenge since the base model has a pushdown stack to capture more complex behaviors which commonly found on reactive systems. We then defined a more general conformance relation for pushdown reactive systems such that it prevents any observable implementation behavior that was not already present in the given specification. Further we gave an efficient algorithm to check conformance in this testing scenario and also showed that it runs in worst case asymptotic polynomial time in the size of both the given specification and the implementation that are put under test.

Adilson Luiz Bonifacio, Arnaldo Vieira Moura

Model based testing is a well-established approach to verify implementations modeled by I/O labeled transition systems (IOLTSs). One of the challenges stemming from model based testing is the conformance checking and the generation of test suites, specially when completeness is a required property. In order to check whether an implementation under test is in compliance with its respective specification one resorts to some form of conformance relation that guarantees the expected behavior of the implementations, given the behavior of the specification. The ioco conformance relation is an example of such a relation, specially suited for asynchronous models. In this work we study a more general conformance relation, show how to generate finite and complete test suites, and discuss the complexity of the test generation mechanism under this more general conformance relation. We also show that ioco conformance is a special case of this new conformance relation, and we investigate the complexity of classical ioco-complete test suites. Further, we relate our contributions to more recent works, accommodating the restrictions of their classes of fault models within our more general approach as special cases, and expose the complexity of generating any complete test suite that must satisfy their restrictions.

Adilson Luiz Bonifacio, Arnaldo Vieira Moura

Completeness is a desirable property of test suites. Roughly, completeness guarantees that a non-equivalent implementation under test will always be identified. Several approaches proposed sufficient, and sometimes also necessary, conditions on the specification model and on the test suite in order to guarantee completeness. Usually, these approaches impose several restrictions on the specification and on the implementations, such as requiring them to be reduced or complete. Further, test cases are required to be non-blocking --- that is, they must run to completion --- on both the specification and the implementation models. In this work we deal test cases that can be blocking, we define a new notion that captures completeness, and we characterize test suite completeness in this new scenario. We establish an upper bound on the number of states of implementations beyond which no test suite can be complete, both in the classical sense and in the new scenario with blocking test cases.