Symstra: A Framework for Generating Object-Oriented Unit Tests Using Symbolic Execution

Abstract

Abstract. Object-oriented unit tests consist of sequences of method invocations. Behavior of an invocation depends on the method's arguments and the state of the receiver at the beginning of the invocation. Correspondingly, generating unit tests involves two tasks: generating method sequences that build relevant receiverobject states and generating relevant method arguments. This paper proposes Symstra, a framework that achieves both test generation tasks using symbolic execution of method sequences with symbolic arguments. The paper defines symbolic states of object-oriented programs and novel comparisons of states. Given a set of methods from the class under test and a bound on the length of sequences, Symstra systematically explores the object-state space of the class and prunes this exploration based on the state comparisons. Experimental results show that Symstra generates unit tests that achieve higher branch coverage faster than the existing test-generation techniques based on concrete method arguments.

Testing Container Classes: Random or Systematic?

“…The empirical evidence on research in this area often focuses on container classes [4,5,6,7,10,12,14,17,19,22,23,26,27,29,30,31,33,34]-containers are an important part of many standard libraries, and bugs in these containers could significantly affect applications, so directing testing efforts to these containers is worthwhile. Testing containers is not only important but also challenging to achieve with some advanced testing technique such as those based on symbolic execution [30].…”

Goal-oriented dynamic test generation

“…Symbolic execution has a variety number of applications in program testing and analysis, for example automated test input generation [25], [112], test sequence generation [130], [140], proving program properties [13], [46], [53], [111], and static detection of runtime errors [18], [30], [36], [50], [127]. A well-known symbolic execution tool is Symbolic Java PathFinder (SPF) [6], [109], which is part of the JPF due to the combinatorial explosion problem of the program path space.…”

JWalk: a tool for lazy, systematic testing of java classes by design introspection and user interaction

“…They typically provide no guarantee about the coverage of randomly generated test sets. According to Xie, et al (2005), neither JCrasher nor JTest satisfy the branchcoverage criterion (Bezier, 1990), let alone the stronger bounded intra-method path coverage criterion (Ball and Larus, 2000). For these, a more systematic approach to test-case generation is required.…”