Pitest

The Mutation Testing tool Pitest is integrated with Kotest via an extension module.

After configuring Pitest, add the io.kotest.extensions:kotest-extensions-pitest module to your dependencies as well:

testImplementation("io.kotest.extensions:kotest-extensions-pitest:<version>")

Note: Since pitest is an extension, we use a different maven group name (io.kotest.extensions) from the core modules.

After doing that, we need to inform Pitest that we're going to use Kotest as a testPlugin:

// Assuming that you have already configured the Gradle/Maven extension
configure<PitestPluginExtension> {
testPlugin.set("Kotest") // <-- Telling Pitest that we're using Kotest
targetClasses.set(listOf("my.company.package.*"))
}

This should set everything up, and running ./gradlew pitest will generate reports in the way you configured.