Search-Based Mutant Selection for Efficient Test Suite Improvement: Evaluation and Results

Context: Search-based techniques have been applied to almost all areas in software engineering, especially to software testing, seeking to solve hard optimization problems. However, the problem of selecting mutants to improve the test suite at a lower cost has not been explored to the same extent as other problems, such as mutant selection for test suite evaluation or test data generation. Objective: In this paper, we apply search-based mutant selection to enhance the quality of test suites efficiently. Namely, we use the technique known as Evolutionary Mutation Testing (EMT), which allows reducing the number of mutants while preserving the power to refine the test suite. Despite reported benefits of its application, the existing empirical results were derived from a limited number of case studies, a particular set of mutation operators and a vague measure, which currently makes it difficult to determine the real performance of this technique. Method: This paper addresses the shortcomings of previous studies, providing a new methodology to evaluate EMT on the basis of the actual improvement of the test suite achieved by using the evolutionary strategy. We make use of that methodology in new experiments with a carefully selected set of real-world C++ case studies. Results: EMT shows a good performance for most case studies and levels of demand of test suite improvement (around 45% less mutants than random selection in the best case). The results reveal that even a reduced subset of mutants selected with EMT can serve to increase confidence in the test suite, especially in programs with a large set of mutants. Conclusions: These results support the use of search-based techniques to solve the problem of mutant selection for a more efficient test suite refinement. Additionally, we identify some aspects that could foreseeably help enhance EMT

Proceedings of the Doctoral Consortium in Computer Science (JIPII 2021)

Actas de las Jornadas de Investigación Predoctoral en Ingeniería InformáticaThis volume contains the proceedings of the Primeras Jornadas de Investigación Predoctoral en Ingeniería Informática - First Doctoral Consortium in Computer Science, JIPII 2021, which was held online on June 15th, 2021. The aim of JIPII 2021 was to provide a forum for PhD students to present and discuss their research under the guidance of a panel of senior researchers. The advances in their PhD theses under development in the Doctoral Program in Computer Science were presented in the Consortium. This Doctoral Program belongs to the Doctoral School of the University of Cadiz (EDUCA). Different stages of research were covered, from the most incipient phase, such as the PhD Thesis plans (or even a Master’s Thesis), to the most advanced phases in which the defence of the PhD Thesis is imminent. We enjoyed twenty very nice and interesting talks, organized in four sessions. We had a total of fifty participants, including speakers and attendees, with an average of thirty-two people in the morning sessions and an average of twenty people in the afternoon sessions. Several people contributed to the success of JIPII 2021. We are grateful to the Academic Committee of the Doctoral Program in Computer Science and the School of Engineering for their support. We would like also to thank the Program Committee for their work in reviewing the papers, as well as all the students and supervisors for their interest and participation. Finally, the proceedings have been published by the Department of Computer Science and Engineering. We hope that you find the proceedings useful, interesting, and challenging

Two case studies on generating administrative process applications with AdminDSL

Some organizations end up reimplementing the same class of business process over and over: an "administrative process", which consists of managing a form through several states and involving various roles in the organization. This results in wasted time that could be dedicated to better understanding the process or dealing with the fine details that are specific to the process. Existing virtual office solutions require specific training and infrastructure andmay result in vendor lock-in. In this paper, we propose using a high-level domain-specific language (AdminDSL) to describe the administrative process and a separate code generator targeting a standard web framework. We have implemented the approach using Xtext, EGL and the Django web framework, and we illustrate it through two case studies: a synthetic examination process which illustrates the architecture of the generated code, and a real-world workplace survey process that identified several future avenues for improvement

MEdit4CEP: A model-driven solution for real-time decision making in SOA 2.0

Organizations all around the world need to manage huge amounts of data from heterogeneous sources every day in order to conduct decision making processes. This requires them to infer what the value of such data is for the business in question through data analysis as well as acting promptly for critical or relevant situations. Complex Event Processing (CEP) is a technology that helps tackle this issue by detecting event patterns in real time. However, this technology forces domain experts to define these patterns indicating such situations and the appropriate actions to be executed in their information systems, generally based on Service-Oriented Architectures (SOAs). In particular, these users face the incommodity of implementing these patterns manually or by using editors which are not user-friendly enough. To deal with this problem, a model-driven solution for real-time decision making in event-driven SOAs is proposed and conducted in this paper. This approach allows the integration of CEP with this architecture type as well as defining CEP domain and event pattern through a graphical and intuitive editor, which also permits automatic code generation. Moreover, the solution is evaluated and its benefits are discussed. As a result, we can assert this is a novel solution for bringing CEP technology closer to any user, positively impacting on business decision making processes

Análisis híbrido: una propuesta práctica

Este artículo defiende la necesidad de introducir el análisis híbrido en las prácticas de las asignaturas en las que se imparte análisis y diseño de algoritmos secuenciales, y presenta un entorno de trabajo adecuado para su realización en el laboratorio. Esta técnica de análisis es una mezcla de las técnicas tradicionales de análisis teórico y empírico: en el análisis híbrido se emplea la primera de ellas para establecer un modelo y la segunda para obtener datos experimentales que, por último, permiten ajustar el modelo mediante regresión

Inference of performance annotations in web service composition models

High-quality services must keep working reliably and efficiently, and service compositions are no exception. As they integrate several internal and external services over the network, they need to be carefully designed to meet their performance requirements. Current approaches assist developers in estimating whether the selected services can fulfill those requirements. However, they do not help developers define requirements for services lacking performance constraints and historical data. Manually estimating these constraints is a time-consuming process which might underestimate or overestimate the required performance, incurring in additional costs. This work presents the first version of two algorithms which infer the missing performance constraints from a service composition model. The algorithms are designed to spread equally the load across the composition according to the probability and frequency each service is invoked, and to check the consistency of the performance constraints of each service with those of the composition

Using Evolutionary Mutation Testing to improve the quality of test suites

Mutation testing is a method used to assess and improve the fault detection capability of a test suite by creating faulty versions, called mutants, of the system under test. Evolutionary Mutation Testing (EMT), like selective mutation or mutant sampling, was proposed to reduce the computational cost, which is a major concern when applying mutation testing. This technique implements an evolutionary algorithm to produce a reduced subset of mutants but with a high proportion of mutants that can help the tester derive new test cases (strong mutants). In this paper, we go a step further in estimating the ability of this technique to induce the generation of test cases. Instead of measuring the percentage of strong mutants within the subset of generated mutants, we compute how much the test suite is actually improved thanks to those mutants. In our experiments, we have compared the extent to which EMT and the random selection of mutants help to find missing test cases in C++ object-oriented systems. We can conclude from our results that the percentage of mutants generated with EMT is lower than with the random strategy to obtain a test suite of the same size and that the technique scales better for complex programs

ModeL4CEP: Graphical domain-specific modeling languages for CEP domains and event patterns

Complex event processing (CEP) is a cutting-edge technology that allows the analysis and correlation of large volumes of data with the aim of detecting complex and meaningful events through the use of event patterns, as well as permitting the inference of valuable knowledge for end users. Despite the great advantages that CEP can bring to expert or intelligent business systems, it poses a substantial challenge to their users, who are business experts but do not have the necessary knowledge and experience using this technology. The main problem these users have to face is precisely hand-writing the code for event pattern definition, which requires them to implement the conditions to be met to detect relevant situations for the domain in question by using a particular event processing language (EPL). In order to respond to this need, in this paper we propose both a graphical domain-specific modeling language (DSML) for facilitating CEP domain definitions by domain experts, and a graphical DSML for event pattern definition by non-technological users. The proposed languages provide high expressiveness and flexibility and are independent of event patterns and actions’ implementation code. This way, domain experts can define the relevant event types and patterns within their business domain, without having to be experts on EPL programming, nor on other complicated computer science technological issues, beyond an understandable and intuitive graphical definition. Furthermore, with these DSMLs, users will also be able to define the actions to be automatically taken once a pattern is detected in the system. Further benefits of these DSMLs are evaluated and discussed in depth in this paper

Una propuesta para una primera asignatura de Algoritmia

En este trabajo presentamos nuestra experiencia con una nueva organización curricular para la materia de análisis y diseño de algoritmos en los primeros cursos de los estudios de Informática y realizamos una propuesta docente para una asignatura introductoria

Automatización de la corrección de prácticas de programación a través del compilador Clang

El proceso de corrección de ejercicios para la enseñanza de lenguajes de programación se ha realizado tradicionalmente de forma manual. En los últimos años se ha avanzado en este aspecto hacia la automatización de la evaluación de las entregas de los alumnos, lo cual viene a mejorar tanto el aprendizaje del alumno como las tareas del profesor. No obstante, uno de los mayores inconvenientes para lograr este objetivo es la limitación en el análisis sintáctico del código para comprobar el cumplimiento de ciertos requisitos en el mismo. Este trabajo muestra cómo el uso de Clang, un compilador maduro de código abierto, puede proporcionar una capacidad de análisis superior mediante el recorrido por el árbol de sintaxis abstracta. Además, se plantea el uso de la prueba de mutaciones como técnica que conciencie a los alumnos de la importancia de diseñar un conjunto completo de casos de prueba para probar sus programas.The process of correction of exercises for the teaching of programming languages has been traditionally accomplished in a manual way. In recent years, several advances have been made regarding this aspect towards the automation of the evaluation of the solutions provided by the students. This support aims to improve both the learning of students and the work of lecturers. However, one of the main drawbacks to achieve this goal is the limitation in the static analysis of the code to check the fulfilment of certain requirements. This paper shows how using Clang, a full-fledged open-source compiler, can provide a greater capacity for analysis through the traversal of the abstract syntax tree. Moreover, the technique known as mutation testing is suggested to make students aware of the importance of designing an adequate test suite to test their applications