Can This Fault Be Detected by Automated Test Generation: A Preliminary Study

Automated test generation can reduce the manual effort to improve software quality. A test generation method employs code coverage, such as the widely-used branch coverage, to guide the inference of test cases. These test cases can be used to detect hidden faults. An automatic tool takes a specific type of code coverage as a configurable parameter. Given an automated tool of test generation, a fault may be detected by one type of code coverage, but omitted by another. In frequently released software projects, the time budget of testing is limited. Configuring code coverage for a testing tool can effectively improve the quality of projects. In this paper, we conduct a preliminary study on whether a fault can be detected by specific code coverage in automated test generation. We build predictive models with 60 metrics of faulty source code to identify detectable faults under eight types of code coverage, such as branch coverage. In the experiment, an off-the-shelf tool, EvoSuite is used to generate test data. Experimental results show that different types of code coverage result in the detection of different faults. The extracted metrics of faulty source code can be used to predict whether a fault can be detected with the given code coverage; all studied code coverage can increase the number of detected faults that are missed by the widely-used branch coverage. This study can be viewed as a preliminary result to support the configuration of code coverage in the application of automated test generation.