SpringKotlinQuickTest

//TestApplicaiton.kt
fun main(args: Array<String>) {
    val application = Application.createSpringApplication()
    application.addInitializers(AbstractIntegrationTest.Initializer())
    application.run(*args)
}

//AbstratIntegrationTest.kt
import org.junit.runner.RunWith
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.context.ApplicationContextInitializer
import org.springframework.context.ConfigurableApplicationContext
import org.springframework.core.env.MapPropertySource
import org.springframework.test.context.ContextConfiguration
import org.springframework.test.context.junit4.SpringRunner

@RunWith(SpringRunner::class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@ContextConfiguration(initializers = [AbstractIntegrationTest.Initializer::class])
abstract class AbstractIntegrationTest {
     class Initializer : ApplicationContextInitializer<ConfigurableApplicationContext> {
        override fun initialize(context: ConfigurableApplicationContext) {
            val env = context.environment
            env.propertySources.addFirst(
                MapPropertySource(
                    "testcontainers", properties
                )
            )
        }

        companion object {
            val properties: Map<String, String>
                get() = java.util.Map.of(
                    "a", "b"
                )
        }
    }
}

//Application.kt

@SpringBootApplication
class Application {
    companion object {
        @JvmStatic
        fun createSpringApplication(): SpringApplication {
            return SpringApplication(Application::class.java)
        }
    }

}

fun main(args: Array<String>) {
    Application.createSpringApplication().run(*args)
}