David Schuler

About me

My research lies in the area of software quality assurance, notably

• Dynamic program analysis: How can we characterize program runs?
• Software testing: How do we know a test is "good enough"?

Projects

Efficient and Effective Mutation Testing

Despite its effectiveness, mutation testing has two issues. First, it requires large computing resources to re-run the test suite again and again. Second, and this is worse, a mutation to the program can keep the program's semantics unchanged -- and thus cannot be detected by any test. Such equivalent mutants act as false positives; they have to be assessed and isolated manually, which is an extremely tedious task.

For that purpose, I have developed Javalanche, framework for mutation testing of Java programs, which addresses both the problems of efficiency and equivalent mutants:

• First, Javalanche is built for efficiency from the ground up, manipulating byte code directly and allowing mutation testing of programs that are several orders of magnitude larger than earlier research subjects.
• Second, Javalanche addresses the problem of equivalent mutants by assessing the impact of mutations on dynamic invariants: The more invariants impacted by a mutation, the more likely it is to be useful for improving test suites.

We have evaluated Javalanche on seven industrial-size programs, confirming its effectiveness. With less than 3% of equivalent mutants, our approach provides a precise and fully automatic measure of the adequacy of a test suite -- making mutation testing, finally, applicable in practice.

For details on the technique, see our paper on Efficient Mutation Testing by Checking Invariant Violations.

Detecting Code Theft with API Birthmark

The corresponding paper was presented at ASE 2007, and got me some nice media coverage (Slashdot · SZ · Heise · Linuxworld · Pressespiegel · Computable · Bild · Entwickler · ACM Technews · Computerzeitung · IDW Online).

A list of all my publications can be found here.

Teaching

Contact