On the Effectiveness of Manual and Automatic Unit Test Generation

The importance of testing has recently seen a significant growth, thanks to its benefits to software design (e.g. think of test-driven development), implementation and maintenance support. As a consequence of this, nowadays it is quite common to introduce a test suite into an existing system, which was not designed for it. The software engineer must then decide whether using tools which automatically generate unit tests (test suites necessary foundations) and how. This paper tries to deal with the issue of choosing the best approach. We will describe how different generation techniques (both manual and automatic) have been applied to a real case study. We will compare achieved results using several metrics in order to identify different approaches benefits and shortcomings. We will conclude showing the measure how the adoption of tools for automatic test creation can shift the trade-off between time and quality.