EvoSuite

Abstract State-of-the-art search-based approaches for test case generation work at test case level, where tests are represented as sequences of statements. These approaches make use of genetic operators (i.e., mutation and crossover) that create test variants by adding, altering, and removing statements from existing tests.

EvoSuite is a search-based tool that automatically generates executable unit tests for Java code (JUnit tests). This paper summarises the results and experiences of EvoSuite participation at the ninth unit testing competition at SBST 2021, where EvoSuite achieved the highest overall score.

Software testing is an important and time-consuming task that is often done manually. In the last decades, researchers have come up with techniques to generate input data (e.g., fuzzing) and automate the process of generating test cases (e.g., search-based testing). However, these techniques are known to have their own limitations: search-based testing does not generate highly-structured data; grammar-based fuzzing does not generate test case structures. To address these limitations, we combine these two techniques. By applying grammar-based mutations to the input data gathered by the search-based testing algorithm, it allows us to co-evolve both aspects of test case generation. We evaluate our approach by performing an empirical study on 20 Java classes from the three most popular JSON parsers across multiple search budgets. Our results show that the proposed approach on average improves branch coverage for JSON related classes by 15% (with a maximum increase of 50%) without negatively impacting other classes.

EvoSuite is a search-based tool that automatically generates executable unit tests for Java code (JUnit tests). This paper summarizes the results and experiences of EvoSuite’s participation at the eighth unit testing competition at SBST 2020, where EvoSuite achieved the highest overall score (406.14 points) for the seventh time in eight editions of the competition.