Mutation Testing
Mutation testing is a software testing technique that evaluates the quality of existing test cases by introducing small, artificial faults (mutations) into the source code and checking if the tests detect them. It helps identify weaknesses in test suites by measuring their ability to catch bugs, providing a metric called mutation score. This approach is used to improve test coverage and reliability beyond traditional code coverage metrics.
Developers should use mutation testing when they need to assess and enhance the effectiveness of their unit or integration tests, particularly in safety-critical systems, financial applications, or projects with high reliability requirements. It is valuable for identifying gaps in test suites that might pass despite code defects, ensuring tests are robust against common programming errors like boundary conditions or logical mistakes.