Feedback-Based Specification, Coding and Testing with JWalk

JWalk is a lazy systematic unit-testing tool for Java, which supports dynamic inference of specifications from code and systematic testing from the acquired specification. This paper describes the feedback-based development methodology that is possible using the JWalk Editor, an original Java-sensitive editor and compiler coupled to JWalk, which helps programmers to prototype Java class designs, generating novel test cases as they code. Systematic exploratory testing alerts the programmer to unusual consequences in the design; and confirmed test results become part of the evolving specification, which adapts continuously to modified classes and extends to subclasses. The cycle of coding, inferring and testing systematically exposes test cases that are often missed in other test-driven development approaches, which rely on programmer intuition to create test cases

Towards quality programming in the automated testing of distributed applications

PhD ThesisSoftware testing is a very time-consuming and tedious activity and accounts for over 25% of the cost of software development. In addition to its high cost, manual testing is unpopular and often inconsistently executed. Software Testing Environments (STEs) overcome the deficiencies of manual testing through automating the test process and integrating testing tools to support a wide range of test capabilities. Most prior work on testing is in single-thread applications. This thesis is a contribution to testing of distributed applications, which has not been well explored. To address two crucial issues in testing, when to stop testing and how good the software is after testing, a statistics-based integrated test environment which is an extension of the testing concept in Quality Programming for distributed applications is presented. It provides automatic support for test execution by the Test Driver, test development by the SMAD Tree Editor and the Test Data Generator, test failure analysis by the Test Results Validator and the Test Paths Tracer, test measurement by the Quality Analyst, test management by the Test Manager and test planning by the Modeller. These tools are integrated around a public, shared data model describing the data entities and relationships which are manipulable by these tools. It enables early entry of the test process into the life cycle due to the definition of the quality planning and message-flow routings in the modelling. After well-prepared modelling and requirements specification are undertaken, the test process and the software design and implementation can proceed concurrently. A simple banking application written using Java Remote Method Invocation (RMI) and Java DataBase Connectivity (JDBC) shows the testing process of fitting it into the integrated test environment. The concept of the automated test execution through mobile agents across multiple platforms is also illustrated on this 3-tier client/server application.The National Science Council, Taiwan: The Ministry of National Defense, Taiwan

SDK development for bridging heterogeneous data sources through connect bridge platform

Nesta dissertação apresentou-se um SDK para a criação de conectores a integrar com o CB Server, que pretende: acelerar o desenvolvimento, garantir melhores práticas e simplificar as diversas atividades e tarefas no processo de desenvolvimento. O SDK fornece uma API pública e simples, suportada por um conjunto de ferramentas, que facilitam o processo de desenvolvimento, explorando as facilidades disponibilizadas através da API. Para analisar a exatidão, viabilidade, integridade e acessibilidade da solução apresentam-se dois exemplos e casos de estudo. Através dos casos de estudo foi possível identificar uma lista de problemas, de pontos sensíveis e melhorias na solução proposta. Para avaliar a usabilidade da API, uma metodologia baseada em vários métodos de avaliação de usabilidade foi estabelecida. O múltiplo caso de estudo funciona como o principal método de avaliação, combinando vários métodos de pesquisa. O caso de estudo consiste em três fases de avaliação: um workshop, uma avaliação heurística e uma análise subjetiva. O caso de estudo envolveu três engenheiros de software (incluindo programadores e avaliadores). A metodologia aplicada gerou resultados com base num método de inspeção, testes de utilizador e entrevistas. Identificou-se não só pontos sensíveis e falhas no código-fonte, mas também problemas estruturais, de documentação e em tempo de execução, bem como problemas relacionados com a experiência do utilizador. O contexto do estudo é apresentado de modo a tirar conclusões acerca dos resultados obtidos. O trabalho futuro incluirá o desenvolvimento de novas funcionalidades. Adicionalmente, pretende-se resolver problemas encontrados na metodologia aplicada para avaliar a usabilidade da API, nomeadamente problemas e falhas no código fonte (por exemplo, validações) e problemas estruturais.In this dissertation, we present an SDK for the creation of connectors to integrate with CB Server which accelerates deployment, ensures best practices and simplifies the various activities and tasks in the development process. The SDK provides a public and simple API leveraged by a set of tools around the API developed which facilitate the development process by exploiting the API facilities. To analyse the correctness, feasibility, completeness, and accessibility of our solution, we presented two examples and case studies. From the case studies, we derived a list of issues found in our solution and a set of proposals for improvement. To evaluate the usability of the API, a methodology based on several usability evaluation methods has been established. Multiple case study works as the main evaluation method, combining several research methods. The case study consists of three evaluation phases – a hands-on workshop, a heuristic evaluation and subjective analysis. The case study involved three computer science engineers (including novice and expert developers and evaluators). The applied methodology generated insights based on an inspection method, a user test, and interviews. We identify not only problems and flaws in the source code, but also runtime, structural and documentation problems, as well as problems related to user experience. To help us draw conclusion from the results, we point out the context of the study. Future work will include the development of new functionalities. Additionally, we aim to solve problems found in the applied methodology to evaluate the usability of the API, namely problems and flaws in the source code (e.g. validations) and structural problems

A verified and optimized Stream X-Machine testing method, with application to cloud service certification

The Stream X-Machine (SXM) testing method provides strong and repeatable guarantees of functional correctness, up to a specification. These qualities make the method attractive for software certification, especially in the domain of brokered cloud services, where arbitrage seeks to substitute functionally equivalent services from alternative providers. However, practical obstacles include: the difficulty in providing a correct specification, the translation of abstract paths into feasible concrete tests, and the large size of generated test suites. We describe a novel SXM verification and testing method, which automatically checks specifications for completeness and determinism, prior to generating complete test suites with full grounding information. Three optimisation steps achieve up to a ten-fold reduction in the size of the test suite, removing infeasible and redundant tests. The method is backed by a set of tools to validate and verify the SXM spec-ification, generate technology-agnostic test suites and ground these in SOAP, REST or rich-client service implementations. The method was initially validated using seven specifications, three cloud platforms and five grounding strategies

Reactive Microservices - An Experiment

Os microserviços são geralmente adotados quando a escalabilidade e flexibilidade de uma aplicação são essenciais para o seu sucesso. Apesar disto, as dependências entre serviços transmitidos através de protocolos síncronos, resultam numa única falha que pode afetar múltiplos microserviços. A adoção da capacidade de resposta numa arquitetura baseada em microserviços, através da reatividade, pode facilitar e minimizar a proliferação de erros entre serviços e na comunicação entre eles, ao dar prioridade à capacidade de resposta e à resiliência de um serviço. Esta dissertação fornece uma visão geral do estado da arte dos microserviços reativos, estruturada através de um processo de mapeamento sistemático, onde são analisados os seus atributos de qualidade mais importantes, os seus erros mais comuns, as métricas mais adequadas para a sua avaliação, e as frameworks mais relevantes. Com a informação recolhida, é apresentado o valor deste trabalho, onde a decisão do projeto e a framework a utilizar são tomadas, através da técnica de preferência de ordem por semelhança com a solução ideal e o processo de hierarquia analítica, respetivamente. Em seguida, é realizada a análise e o desenho da solução, para o respetivo projeto, onde se destacam as alterações arquiteturais necessárias para o converter num projeto de microserviços reativo. Em seguida, descreve-se a implementação da solução, começando pela configuração do projeto necessária para agilizar o processo de desenvolvimento, seguida dos principais detalhes de implementação utilizados para assegurar a reatividade e como a framework apoia e simplifica a sua implementação, finalizada pela configuração das ferramentas de métricas no projeto para apoiar os testes e a avaliação da solução. Em seguida, a validação da solução é investigada e executada com base na abordagem Goals, Questions, Metrics (GQM), para estruturar a sua análise relativamente à manutenção, escalabilidade, desempenho, testabilidade, disponibilidade, monitorabilidade e segurança, finalizada pela conclusão do trabalho global realizado, onde são listadas as contribuições, ameaças à validade e possíveis trabalhos futuros.Microservices are generally adopted when the scalability and flexibility of an application are essential to its success. Despite this, dependencies between services transmitted through synchronous protocols result in one failure, potentially affecting multiple microservices. The adoption of responsiveness in a microservices-based architecture, through reactivity, can facilitate and minimize the proliferation of errors between services and in the communication between them by prioritizing the responsiveness and resilience of a service. This dissertation provides an overview of the reactive microservices state of the art, structured through a systematic mapping process, where its most important quality attributes, pitfalls, metrics, and most relevant frameworks are analysed. With the gathered information, the value of this work is presented, where the project and framework decision are made through the technique of order preference by similarity to the ideal solution and the analytic hierarchy process, respectively. Then, the analysis and design of the solution are idealized for the respective project, where the necessary architectural changes are highlighted to convert it to a reactive microservices project. Next, the solution implementation is described, starting with the necessary project setup to speed up the development process, followed by the key implementation details employed to ensure reactivity and how the framework streamlines its implementation, finalized by the metrics tools setup in the project to support the testing and evaluation of the solution. Then, the solution validation is traced and executed based on the Goals, Questions, Metrics (GQM) approach to structure its analysis regarding maintainability, scalability, performance, testability, availability, monitorability, and security, finalized by the conclusion of the overall work done, where the contributions, threats to validity and possible future work are listed

Automated specification-based testing of graphical user interfaces

Tese de doutoramento. Engenharia Electrónica e de Computadores. 2006. Faculdade de Engenharia. Universidade do Porto, Departamento de Informática, Escola de Engenharia. Universidade do Minh

Test Generation and Dependency Analysis for Web Applications

In web application testing existing model based web test generators derive test paths from a navigation model of the web application, completed with either manually or randomly generated inputs. Test paths extraction and input generation are handled separately, ignoring the fact that generating inputs for test paths is difficult or even impossible if such paths are infeasible. In this thesis, we propose three directions to mitigate the path infeasibility problem. The first direction uses a search based approach defining novel set of genetic operators that support the joint generation of test inputs and feasible test paths. Results show that such search based approach can achieve higher level of model coverage than existing approaches. Secondly, we propose a novel web test generation algorithm that pre-selects the most promising candidate test cases based on their diversity from previously generated tests. Results of our empirical evaluation show that promoting diversity is beneficial not only to a thorough exploration of the web application behaviours, but also to the feasibility of automatically generated test cases. Moreover, the diversity based approach achieves higher coverage of the navigation model significantly faster than crawling based and search based approaches. The third approach we propose uses a web crawler as a test generator. As such, the generated tests are concrete, hence their navigations among the web application states are feasible by construction. However, the crawling trace cannot be easily turned into a minimal test suite that achieves the same coverage due to test dependencies. Indeed, test dependencies are undesirable in the context of regression testing, preventing the adoption of testing optimization techniques that assume tests to be independent. In this thesis, we propose the first approach to detect test dependencies in a given web test suite by leveraging the information available both in the web test code and on the client side of the web application. Results of our empirical validation show that our approach can effectively and efficiently detect test dependencies and it enables dependency aware formulations of test parallelization and test minimization