In this paper, we examine whether changes in coverage can be used to detect non-equivalent mutants. In a sample of 140 manually classified mutations of seven Java programs with 5000 to 100 000 lines of code, we found that: the problem is serious and widespread (45% of all undetected mutants are equivalent); manual classification takes time (15 min per mutation); coverage is a simple and effective means to identify equivalent mutants (with a classification precision of 75% and 56% recall).

Mutation testing of multithreaded code is highly time intensive: for each mutant, every test case may be explored for multiple possible thread schedules. This paper introduces a general framework for efficient exploration that can reduce the time for mutation testing of multithreaded code. The paper presents five techniques within the framework that are implemented in a tool calledMuTMuT. Evaluation of MuTMuT on mutation testing of 12 multithreaded programs shows that it indeed substantially reduces the time required.

This paper focuses on the theory of formal verification of functional properties of graph rewriting-based model processing programs often referred as model transformations. A formal framework has been developed for the declarative description of individual graph-rewriting rules and for the specification of the functional properties to be verified. Methods have been proposed for the semi-automated analysis of the transformations, and the implementation of framework has been outlined as a part of visual modeling and transformation system.