Kotlin - running an integration test, error `fun main is already defined` - maven

Question

I have written an integration test for a Web application but I don't know how to run this test. Maven build fails with the following error when I execute mvn test
[INFO] Compiling Kotlin sources from [src/main/kotlin]
[INFO] Classpath: <...>
[INFO] Classes directory is <...>\target\classes
[INFO] Module name is demo
[ERROR] <...>\src\main\kotlin\demo\Application.kt: (9, 1) 'public fun main(args: kotlin.Array<kotlin.String>): kotlin.Unit' is already defined in demo
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
Here is my main class (Application.kt)
package demo
import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication
#SpringBootApplication
open class Application
fun main(args: Array<String>) {
SpringApplication.run(Application::class.java, *args)
}
Here is a part of my test class
package demo
import org.junit.runner.RunWith
import org.springframework.boot.test.SpringApplicationConfiguration
import org.springframework.boot.test.WebIntegrationTest
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner
import demo.Application
import demo.model.City
import demo.repository.CityRepository
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = Application.class)
#WebIntegrationTest({"server.port=8080"})
class CityControllerTest {
#Autowired
private var cityRepository: CityRepository?
private val restTemplate: RestTemplate = TestRestTemplate()
// ...
}
There is no such error when I execute mvn clean test. So I suppose Kotlin is frightened of previously compiled classes. Though I am very unsure...
What is the right way to run an integration test?

Answer 1

It is a bug (https://youtrack.jetbrains.com/issue/KT-10051). Already fixed and the fix will be delivered very soon