Testing Pushdown Systems

TL;DR

This paper extends model-based testing to pushdown systems with stacks, introducing a conformance relation and an efficient polynomial-time algorithm for testing reactive systems with complex behaviors.

Contribution

It introduces a new conformance relation and an efficient polynomial-time algorithm for testing pushdown reactive systems with stacks.

Findings

Conformance checking runs in polynomial time.

The approach handles complex pushdown behaviors.

Test suite generation for pushdown systems is feasible.

Abstract

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.