Understanding Mutation Testing

Mutation testing evaluates the effectiveness of test suites by introducing small faults, known as mutants, into the code and measuring whether tests can detect these changes. This approach goes beyond traditional line coverage, as it helps assess the quality of tests by ensuring that they not only run through code but also validate its functionality properly. For instance, if a function's operation is altered from addition to subtraction, effective tests should fail, revealing potential weaknesses in test coverage. Thus, mutation testing fosters confidence in the robustness of test suites and assures that they effectively identify real bugs.