Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

Aplicaciones de la teoría de la información y la inteligencia artificial al testing de software

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Ingeniería de Sistemas lnformáticos y de Computación, leída el 4-05-2022Software Testing is a critical field for the software industry, as it has the main tools used to ensure the reliability of the produced software. Currently, mor then 50% of the time and resources for creating a software product are diverted to testing tasks, from unit testing to system testing. Moreover, there is a huge interest into automatising this field, as software gets bigger and the amount of required testing increases. however, software Testing is not only an industry oriented field; it is also a really interesting field with a noble goal (improving the reliability of software systems) that at the same tieme is full of problems to solve....Es Testing Software es un campo crítico para la industria del software, ya que éste contienen las principales herramientas que se usan para asegurar la fiabilidad del software producido. Hoy en día, más del 50% del tiempo y recursos necesarios para crear un producto software son dirigidos a tareas de testing, desde el testing unitario al testing a nivel de sistema. Más aún, hay un gran interés en automatizar este campo, ya que el software cada vez es más grande y la cantidad de testing requerido crece. Sin embargo, el Testing de Software no es solo un campo orientado a la industria; también es un campo muy interesante con un objetivo noble (mejorar la fiabilidad de los sistemas software) que al mismo tiempo está lleno de problemas por resolver...Fac. de InformáticaTRUEunpu

Model Based Security Testing for Autonomous Vehicles

The purpose of this dissertation is to introduce a novel approach to generate a security test suite to mitigate malicious attacks on an autonomous system. Our method uses model based testing (MBT) methods to model system behavior, attacks and mitigations as independent threads in an execution stream. The threads intersect at a rendezvous or attack point. We build a security test suite from a behavioral model, an attack type and a mitigation model using communicating extended finite state machine (CEFSM) models. We also define an applicability matrix to determine which attacks are possible with which states. Our method then builds a comprehensive test suite using edge-node coverage that allows for systematic testing of an autonomous vehicle

Parallel algorithms for generating distinguishing sequences for observable non-deterministic FSMs

A distinguishing sequence (DS) for a finite state machine (FSM) is an input sequence that distinguishes every pair of states of the FSM. There are techniques that generate a test sequence with guaranteed fault detection power and it has been found that shorter test sequence can be produced if DSs are used. Despite these benefits, however, until recently the only published DS generation algorithms have been for deterministic FSMs. This paper develops a massively parallel algorithm, which can be used in GPU Computing, to generate DSs from partial observable non-deterministic FSMs. We also present the results of experiments using randomly generated FSMs and some benchmark FSMs. The results are promising and indicate that the proposed algorithm can derive DSs from partial observable non-deterministic FSMs with 32,000 states in an acceptable amount of time.This work is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant #1059B191400424 and by the NVIDIA corporation

On conformance testing of systems communicating by Rendezvous

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Fail-Safe Test Generation of Safety Critical Systems

This dissertation introduces a technique for testing proper failure mitigation in safety critical systems. Unlike other approaches which integrate behavioral and failure models, and then generate tests from the integrated model, we build safety mitigation tests from an existing behavioral test suite, using an explicit mitigation model for which we generate mitigation paths which are then woven at selected failure points into the original test suite to create failure-mitigation tests (safety mitigation test)

Improving fault coverage and minimising the cost of fault identification when testing from finite state machines

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Software needs to be adequately tested in order to increase the confidence that the system being developed is reliable. However, testing is a complicated and expensive process. Formal specification based models such as finite state machines have been widely used in system modelling and testing. In this PhD thesis, we primarily investigate fault detection and identification when testing from finite state machines. The research in this thesis is mainly comprised of three topics - construction of multiple Unique Input/Output (UIO) sequences using Metaheuristic Optimisation Techniques (MOTs), the improved fault coverage by using robust Unique Input/Output Circuit (UIOC) sequences, and fault diagnosis when testing from finite state machines. In the studies of the construction of UIOs, a model is proposed where a fitness function is defined to guide the search for input sequences that are potentially UIOs. In the studies of the improved fault coverage, a new type of UIOCs is defined. Based upon the Rural Chinese Postman Algorithm (RCPA), a new approach is proposed for the construction of more robust test sequences. In the studies of fault diagnosis, heuristics are defined that attempt to lead to failures being observed in some shorter test sequences, which helps to reduce the cost of fault isolation and identification. The proposed approaches and techniques were evaluated with regard to a set of case studies, which provides experimental evidence for their efficacy.Brunel Research Initiative and Enterprise Fund (BRIEF) Award from Brunel University and Departmental bursary from Department of Information Systems and Computing, Brunel Universit

Reverse Engineering and Testing of Rich Internet Applications

The World Wide Web experiences a continuous and constant evolution, where new initiatives, standards, approaches and technologies are continuously proposed for developing more effective and higher quality Web applications. To satisfy the growing request of the market for Web applications, new technologies, frameworks, tools and environments that allow to develop Web and mobile applications with the least effort and in very short time have been introduced in the last years. These new technologies have made possible the dawn of a new generation of Web applications, named Rich Internet Applications (RIAs), that offer greater usability and interactivity than traditional ones. This evolution has been accompanied by some drawbacks that are mostly due to the lack of applying well-known software engineering practices and approaches. As a consequence, new research questions and challenges have emerged in the field of web and mobile applications maintenance and testing. The research activity described in this thesis has addressed some of these topics with the specific aim of proposing new and effective solutions to the problems of modelling, reverse engineering, comprehending, re-documenting and testing existing RIAs. Due to the growing relevance of mobile applications in the renewed Web scenarios, the problem of testing mobile applications developed for the Android operating system has been addressed too, in an attempt of exploring and proposing new techniques of testing automation for these type of applications

Complete Model-Based Testing Applied to the Railway Domain

Testing is the most important verification technique to assert the correctness of an embedded system. Model-based testing (MBT) is a popular approach that generates test cases from models automatically. For the verification of safety-critical systems, complete MBT strategies are most promising. Complete testing strategies can guarantee that all errors of a certain kind are revealed by the generated test suite, given that the system-under-test fulfils several hypotheses. This work presents a complete testing strategy which is based on equivalence class abstraction. Using this approach, reactive systems, with a potentially infinite input domain but finitely many internal states, can be abstracted to finite-state machines. This allows for the generation of finite test suites providing completeness. However, for a system-under-test, it is hard to prove the validity of the hypotheses which justify the completeness of the applied testing strategy. Therefore, we experimentally evaluate the fault-detection capabilities of our equivalence class testing strategy in this work. We use a novel mutation-analysis strategy which introduces artificial errors to a SystemC model to mimic typical HW/SW integration errors. We provide experimental results that show the adequacy of our approach considering case studies from the railway domain (i.e., a speed-monitoring function and an interlocking-system controller) and from the automotive domain (i.e., an airbag controller). Furthermore, we present extensions to the equivalence class testing strategy. We show that a combination with randomisation and boundary-value selection is able to significantly increase the probability to detect HW/SW integration errors

Combining centralised and distributed testing

Many systems interact with their environment at distributed interfaces (ports) and sometimes it is not possible to place synchronised local testers at the ports of the system under test (SUT). There are then two main approaches to testing: having independent local testers or a single centralised tester that interacts asynchronously with the SUT. The power of using independent testers has been captured using implementation relation \dioco. In this paper we define implementation relation \diococ for the centralised approach and prove that \dioco and \diococ are incomparable. This shows that the frameworks detect different types of faults and so we devise a hybrid framework and define an implementation relation \diocos for this. We prove that the hybrid framework is more powerful than the distributed and centralised approaches. We then prove that the Oracle problem is NP-complete for \diococ and \diocos but can be solved in polynomial time if we place an upper bound on the number of ports. Finally, we consider the problem of deciding whether there is a test case that is guaranteed to force a finite state model into a particular state or to distinguish two states, proving that both problems are undecidable for the centralised and hybrid frameworks