Contract-Based Software Component Testing with UML Models

Improving model-based component testability can further model-based approaches to software component testing (SCT) for desirable testing effectiveness. Component contracts are useful testing-support artefacts to improve component testability. This paper presents a new contract-based SCT technique, Test by Contract (TbC), which extends the Design by Contract concept to the SCT domain, and leverages UML-based testing with the contract mechanism to design model-based test contracts for UML-based SCT. We introduce a new concept of Contract for Testability as the principal goal of the TbC technique, and develop a set of important contract-oriented concepts (test contract, effectual contract scope, and internal/external test contract) and useful test criteria to improve model-based testability. We develop a useful stepwise TbC working process, and use a case study to demonstrate how to put the TbC technique into practice to undertake contract-based SCT with UML models.