Testing-Based Conceptual Schema Validation in a Model-Driven Environment

Resumo

Despite much scepticism and problems for its adoption, the Model-Driven Development (MDD) is being used and improved to provide many inherent benefits for industry. One of its greatest benefits is the ability to handle the complexity of software development by raising the abstraction level. Models are expressed using concepts that are not related to a specific implementation technology (e.g. Unified Modelling Language -UML, Object Constraint Language -OCL, Action Language for Foundational UML -ALF), which means that the models can be easier to specify, maintain and document. As in Model-Driven Engineering (MDE), the primary artefacts are the conceptual models, efforts are focused on their creation, testing and evolution at different levels of abstraction through transformations because if a conceptual schema has defects, these are passed on to the following stages, including coding. Thus, one of the challenges for researchers and developers in Model-Driven Development is being able to identify defects early on, at the conceptual schema level, as this helps reduce development costs and improve software quality. Over the last decade, little research work has been performed in this area. Some of the causes of this are the high theoretical complexity of testing conceptual schemas and the lack of adequate software support. This research area thus admits new methods and techniques, facing challenges such as generation of test cases using information external to the conceptual schemas (i.e. requirements), the measurement of possible automation, selection and prioritization of test cases, the need for an efficient support tool using standard semantics, the opportune feedback to support the software quality assurance process and facilitate making decisions based on the analysis and interpretation of the results. The aim of this thesis is to mitigate some of the problems that affect conceptual schema validation by providing a novel testing-based validation framework based on Model-Driven Development. The use of MDD improves abstraction, automation and reuse, which allows us to alleviate the complexity of our validation framework. Furthermore, by leveraging MDD techniques (such as metamodeling, model transformations, and models at runtime), our framework supports four phases of the testing process: test design, test case generation, test case execution and the evaluation of the results. In order to provide software support for our proposal, we developed the CoSTest ALF-based testing environment. To ensure that CoSTest offers the necessary functionality, we first identified a set of functional requirements. Then, after these requirements were identified, we defined the architecture and testing environment of the validation framework, and finally we implemented the architecture in the Eclipse context. CoSTest has been developed to test several properties on the executable model, such as syntactic correctness (i.e. all the elements in the model conform to the syntax of the language in which it is described), consistency between the structural and behavioural parts (its integrity constraints) and completeness (i.e. all possible changes on the system state can be performed through the execution of the operations defined in the executable model). For defective models, the CoSTest report returns a meaningful feedback that helps locate and repair any defects detected.