Though ensuring logical consistency between flows in use case specifications (UCSs) and high‐level business processes is a prerequisite and foundation for generating high‐quality, full‐coverage test cases, this task still primarily relies on manual effort. To address this limitation, a large language model (LLM)‐assisted test‐driven approach is proposed, which introduces a formal structure to guide LLMs in generating UCSs based on natural language requirements. Specifically, to validate the consistency of UCS flows with high‐level business process logic, UML activity and state machine diagrams are used as specific modeling methods for such processes. Furthermore, three novel rules are proposed to validate the consistency: business objects are incorporated to not only horizontally connect UCSs with these models but also vertically bridge different abstraction levels of requirements. To normalize this methodology, a comprehensive framework is established—this framework enables bidirectional traceability between requirements and testing while simultaneously building a feedback loop that integrates requirements, testing, and process models. Experimental results show that the approach not only improves the requirements specification quality but also facilitates semi‐automatic generation of test cases for acceptance testing, thereby enhancing the efficiency of the overall development process.

We propose a tester-based symbolic algorithm to incrementally generate tree-like witnesses (the dual concept of counterexamples) for branching-time logic CTL*. The CTL* witnesses are state transition directed graphs of tree-like structure in which all strongly connected components are cycles, and all branches are lasso paths with shortest prefixes. The states and transitions in these graphs may be respectively attached with satisfied state and path subformulas as annotations for intelligibility. The correctness of the lasso path generation algorithm is proved. We have developed an ordered binary decision diagrams based symbolic model checker MCTK2 for CTL* in which the proposed witness generation algorithm has been implemented. To make the generated witnesses graphs more succinct, several optimization strategies are applied to reduce the number of annotations and avoid constructing branching paths as much as possible. The interactive visualization interface of MCTK2 enables users to conveniently inspect counterexamples and expand branches of interest such that they can incrementally analyze larger and more complex counterexamples.

Regular expressions have been widely studied due to their expressiveness and flexibility for various applications. A common yet challenging way to ensure the quality of regular expressions is regular expression testing. In this work, we study coverage criteria-based string generation for testing regular expressions. First, we propose a notion of pairwise coverage criterion for regular expressions and analyze the subsumption relationships with existing coverage criteria for both regular grammars and finite automata. Second, we design an algorithm that given as an input a regular expression, outputs a small set of strings that satisfies the pairwise coverage criterion. Third, we extend the coverage criterion and the generation algorithm to further deal with regular operators counting and interleaving. Fourth, we experimentally demonstrate the effectiveness and efficiency of our algorithms by testing element-type definitions of real-world XML schemas. Finally, we identify more applications of pairwise coverage and its corresponding generation algorithm and show that they can be used to generate characteristic samples for certain regular expression learning algorithms that follow Gold’s learning paradigm of learning (identification) in the limit. These results are not only theoretically meaningful but also useful for practical applications involved with regular expressions.

Producing sentences from a grammar, according to various criteria, is required in many applications. It is also a basic building block for grammar engineering. This paper presents a toolkit for context-free grammars, which mainly consists of several algorithms for sentence generation or enumeration and for coverage analysis for context-free grammars. The toolkit deals with general context-free grammars. Besides providing implementations of algorithms, the toolkit also provides a simple graphical user interface, through which the user can use the toolkit directly. The toolkit is implemented in Java and is available at http://lcs.ios.ac.cn/zhiwu/toolkit.php. In the paper, the overview of the toolkit and the description of the GUI are presented, and experimental results and preliminary applications of the toolkit are also contained.