mutation-testing

Mutation testing for Kotlin Gradle projects is bootstrapped via the info.solidsoft.pitest plugin with Kotlin-sane defaults, providing preflight checks and scoped execution against changed classes to evaluate test quality beyond line coverage.

Triage surviving mutants from mutations.xml by using a dedicated workflow to separate likely-equivalent mutants from killable ones, allowing you to focus your test refinement efforts on actual killable mutations.

Scoped mutation testing on changed classes is supported through the pitest Gradle plugin configuration, enabling targeted mutation analysis rather than running mutations across the entire JVM project test suite.

Mutation testing improves test quality beyond line coverage by injecting faults into code and evaluating how many mutants survive, then driving a kill-survivor workflow to propose targeted tests and refine assertions.

Existing tests are required before running mutation testing with pitest, as the technique evaluates test effectiveness by checking whether your current test suite can detect and kill injected code mutants.

Pitest reports surviving mutants that cannot be killed when they are likely-equivalent mutants, which produce functionally identical behavior and must be triaged out of the kill queue using the provided triage script.