Generating effective test cases based on satisfiability modulo theory solvers for service-oriented workflow applications

Abstract

Web Service Business Process Execution Language (WS-BPEL) is one of the most popular service-oriented workflow applications. The unique features (e.g. dead path elimination semantics and correlation mechanism) of WS-BPEL applications have raised enormous problems to its test case generation, especially in unit testing. Existing studies mainly assume that each path in the control flow graphs that correspond to WS-BPEL applications is feasible, which always yields imprecise test cases or complicates testing results. The current study tackles this problem based on satisfiability modulo theory solvers. First, a new coverage criterion is proposed to measure the quality of test sets for testing WS-BPEL applications. Second, decomposition algorithms are presented to obtain test paths that meet the proposed coverage criterion. Finally, this paper symbolically encodes each test path with several constraints by capturing the unique features of WS-BPEL. These constraints are solved and the test cases (test paths and test data) are obtained with the help of satisfiability modulo theory solvers to test WS-BPEL applications effectively. Experiments are conducted using our approach and other typical approaches (e.g. message-sequence generation-based approach and concurrent path analysis approach) with 10 WS-BPEL applications. Experimental results demonstrate that the test cases generated by our approach can avoid instantiating idle instance and expose more faults.

Test Case Prioritization for Service-Oriented Workflow Applications: A Perspective of Modification Impact Analysis

“…In this section, a well-known and well-designed application, travel agency application, adapted from Travel [15,19], is used as a motivating example to inspire our approach. First of all, we briefly outline this application.…”

“…For this reason, we propose a method based on satisfiability module theory solver in reference [19], which is a message sequence generated on a structured basis, and uses concurrent BPEL activity path coverage standard to sample the execution of WS-BPEL. Because DPE and association mechanism are considered, this method will not instantiate any idle instances.…”

Test Input Data Generation for Choiceless Program Nets

“…Satisfiability Modulo Theory (SMT for short) is one of the central problems with both theoretical and practical interests in computer science. It is the problem to determine whether a formula expressing constraint conditions has a solution [13]. For example, a solution of the following formula is a set of variable values, e.g.…”

“…In recent years, there has been enormous progress in dealing with a large scale of problems that can be solved by SMT solvers [13], such as Z3, Yices, and so on [14,15]. If the constraint conditions of test input data for each subnet can be obtained, we need only to use SMT solvers to find the test input data, which means our software testing problem can be solved.…”