Kotest Pitest Extension

This page introduces the Pitest extension.

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The mutation testing tool Pitest integrates with Kotest through an extension module.

Gradle configuration

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

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

NOTE: Because Pitest is an extension, it uses a different Maven group name, io.kotest.extensions, from the core modules.

Then you need to tell Pitest that you will use Kotest as the test plugin:

// Assuming that you have already configured the Gradle/Maven extension
configure<PitestPluginExtension> {
    // testPlugin.set("Kotest")    // needed only with old PIT <1.6.7, otherwise having kotest-extensions-pitest on classpath is enough
    targetClasses.set(listOf("my.company.package.*"))
}

Maven configuration

First, configure the Maven Pitest plugin:

<plugin>
    <groupId>org.pitest</groupId>
    <artifactId>pitest-maven</artifactId>
    <version>${pitest-maven.version}</version>
    <configuration>
        <targetClasses>...</targetClasses>
        <coverageThreshold>...</coverageThreshold>
        ... other configurations as needed        
    </configuration>
</plugin>

Then add a dependency on the Pitest Kotest extension:

<dependencies>
  ... the other Kotest dependencies like kotest-runner-junit5-jvm 
  <dependency>
    <groupId>io.kotest.extensions</groupId>
    <artifactId>kotest-extensions-pitest</artifactId>
    <version>${kotest-extensions-pitest.version}</version>
    <scope>test</scope>
  </dependency>
</dependencies>

This is enough to run Pitest and obtain reports as described in the Maven Pitest plugin documentation.

References

Pitest | Kotest