Create integrationTest source tree in Gradle with Kotlin DSL

gistfile1.txt

val integrationTest = java.sourceSets.create("integrationTest").apply {
    compileClasspath += sourceSets.test.get().compileClasspath
    runtimeClasspath += sourceSets.test.get().runtimeClasspath
    java.srcDirs("src/integration-test/kotlin")
}

tasks.create("integrationTest", Test::class) {
    group = "verification"
    description = "Runs integration tests."
    testClassesDirs = integrationTest.output.classesDirs
    classpath = integrationTest.runtimeClasspath
    shouldRunAfter("test")
}