Scaling up automated test generation: Automatically generating maintainable regression unit tests for programs

This paper presents an automatic technique for generating maintainable regression unit tests for programs. We found previous test generation techniques inadequate for two main reasons. First. they were designed for and evaluated upon libraries rather than applications. Second, they were designed to find bugs rather than to create maintainable regression test suites: the test suites that they generated were brittle and hard to understand. This paper presents a suite of techniques that address these problems by enhancing an existing unit test generation system. In experiments using an industrial system, the generated tests achieved good coverage and mutation kill score, were readable by the product´s developers, and required few edits as the system under test evolved. While our evaluation is in the context of one test generator, we are aware of many research systems that suffer similar limitations, so our approach and observations are more generally relevant.