Based On Uml Sequence Diagram Of The Scene Test Case Generation

The anima of software is quality. Software testing is a crucial stage during the software development. It's the key to ensure the software quality and to improve the software reliability. The research on software testing theories and effective testing approaches has become an active topic in the field of software engineering. In software testing, test case generation is the most difficult, expensive and tedious task. Software testers need methodologies and tools to facilitate test case generation. And the automation of the process could significantly improve the software quality and reduce the costs of software development.UML is a standard software modeling language in object-oriented system analysis and design. UML uses a series of views to describe different aspect of software systems. UML sequence diagram is used to describe dynamic behaviors of a software system through the message transmission's time order of the interactive objects, can serve as a valuable information source in software integration test. Because UML model can be created at design stage, test case generation from UML models can reuse the existing design results and reduce the total costs of software test. Accordingly, it is significant to industry in which UML has been widely applied.This paper describes an approach to automatically generate scenario test cases based on UML sequence diagrams with the combination of state diagrams and class diagrams. First of all, the paper gives a formal definition of UML sequence diagrams. Then the paper describes the algorithms of automatically generating scenario test cases form a UML sequence diagram. A sequence diagram is converted to a DAG graph whose nodes are events in the sequence diagram. During a depth-first search in the DAG graph, all testing scenarios can be derived. The issues of the branches and loops in UML sequence diagrams are taken into consideration. Then, the method analyzes each scenario and applies the category-partition method to find environmental conditions related to each scenario and combine them with method call sequence, input and output to construct a test case for each scenario. The method is shown with a case study. Finally, the designs of scenario test case generator (STCG.) which generate test cases automatically are presented.