Visual contract extractor: A tool for reverse engineering visual contracts using dynamic analysis

Visual contracts model the operations of classes, components or services by pre- and post-conditions formalised as graph transformation rules. They provide a precise but intuitive notation to test, document and analyse software systems. However, due to their detailed level of specification of data states and transformations, modelling a real application is a complex and error-prone process. Rather than adopting a top-down modelling approach, we follow a dynamic bottom-up approach to reverse engineer visual contracts from object-oriented programs based on tracing the execution of operations. We developed the Visual Contract Extractor (VCE), a dynamic analysis tool which supports the reverse engineering of visual operation contracts from Java programs. We explore the main features of the tool using two case studies and discuss usage scenarios ranging from traditional program understanding to novel applications in the field of model-based engineering. A screencast demonstrating the tool is provided at https://www.youtube.com/watch?v=VtTx8UHgRGo.