Note
Looking for help? We’ve got you covered! ❤️
Mutation Testing is a fault-based software testing technique. It evaluates the quality of a test suite by calculating mutation score and showing gaps in semantic coverage. It does so by creating several slightly modified versions of the original program, mutants, and running the test suite against each of them. A mutant is considered to be killed if the test suite detects the change, or survived otherwise. A mutant is killed if at least one of the tests starts failing.
Each mutation of original program is based on a set of mutation operators (or mutators). A mutator is a predefined rule that either changes or removes an existing statement or expression in the original program. Each rule is deterministic: the same set of mutation operators applied to the same program results in the same set of mutants.
Mutation score is a ratio of killed vs total mutants. E.g., if seven out of ten mutants are killed, then the score is 0.7, or 70%. The higher the score the better.