Developer Kit

Mutation Testing Driver

Runs mutation testing to assess whether the test suite would catch small deliberate bugs, then reports mutation survival rate and prioritized test improvements. Useful for measuring real test quality beyond line coverage. Engineers shipping code to critical paths (payments, auth, licensing), tech leads enforcing test-quality bars, teams preparing for high-stakes deploys, applied researchers claiming "100% coverage" and wanting to know what that actually means. A test suite at 90% line coverage can still miss entire classes of bugs because hitting a line is not the same as asserting its behavior. Mutation testing — introducing small bugs into the code and measuring how many the tests catch — is the standard way to measure real test quality, but the tooling is underused because setup and interpretation are painful. A structured driver runs the mutation tool, parses the output, and turns it into actionable test improvements rather than a raw survival rate.