Christoph Csallner

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JCrasher is an automatic robustness testing tool for Java code. JCrasher examines the type information of a set of Java classes and constructs code fragments that will create instances of different types to test the behavior of public methods under random data. JCrasher attempts to detect bugs by causing the program under test to “crash”, that is, to throw(More)
We present an automatic error-detection approach that combines static checking and concrete test-case generation. Our approach consists of taking the abstract error conditions inferred using theorem proving techniques by a static checker (ESC/Java), deriving specific error conditions using a constraint solver, and producing concrete test cases (with the(More)
Dynamically discovering likely program invariants from concrete test executions has emerged as a highly promising software engineering technique. Dynamic invariant inference has the advantage of succinctly summarizing both "expected" program inputs and the subset of program behaviors that is normal under those inputs. In this paper, we introduce a technique(More)
Many static and dynamic analyses have been developed to improve program quality. Several of them are well known and widely used in practice. It is not entirely clear, however, how to put these analyses together to achieve their combined benefits. This paper reports on our experiences with building a sequence of increasingly more powerful combinations of(More)
Database-centric applications (DCAs) are common in enterprise computing, and they use nontrivial databases. Testing of DCAs is increasingly outsourced to test centers in order to achieve lower cost and higher quality. When releasing proprietary DCAs, its databases should also be made available to test engineers, so that they can test using real data.(More)
Coding against interfaces is a powerful technique in object-oriented programming. It decouples code and enables independent development. However, code decoupled via interfaces poses additional challenges for testing and dynamic execution, as not all pieces of code that are necessary to execute a piece of code may be available. For example, a client class(More)
Test coverage is an important metric of software quality, since it indicates thoroughness of testing. In industry, test coverage is often measured as statement coverage. A fundamental problem of software testing is how to achieve <i>higher</i> statement coverage <i>faster</i>, and it is a difficult problem since it requires testers to cleverly find input(More)
We explore the automatic generation of test data that respect constraints expressed in the Object-Role Modeling (ORM) language. ORM is a popular conceptual modeling language, primarily targeting database applications, with significant uses in practice. The general problem of even checking whether an ORM diagram is satisfiable is quite hard: restricted forms(More)