Mutation Test Suite Optimizer

Coverage says "this line ran." Mutation testing says "this line ran AND if it were wrong, a test would catch it." Surviving mutants are lines where the test suite is blind.

How it works

1. Mutate: Apply a small change to the code. > → >=. + → -. return x → return None.
2. Run tests: Does any test fail?
3. Killed if a test fails — the suite noticed the bug. Survived if all pass — the suite is blind here.
4. Mutation score = killed / total. Higher is better. > 80% is good.

Standard mutation operators