I am working on refactoring a Spring Boot application from Java to Kotlin. I have made the necessary updates to the build.gradle file.

Firstly, I refactored the Application class from Java to Kotlin. The application is running fine; however, when building the application, I encounter the following error for every unit test class:

ProjectServiceTest > initializationError FAILED
    java.lang.IllegalStateException: Unable to find a @SpringBootConfiguration. You need to use @ContextConfiguration or @SpringBootTest(classes=...) with your test.
        at org.springframework.util.Assert.state(Assert.java:76)
        at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.findConfigurationClass(SpringBootTestContextBootstrapper.java:246)
        at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.getOrFindConfigurationClasses(SpringBootTestContextBootstrapper.java:233)
        at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.processMergedContextConfiguration(SpringBootTestContextBootstrapper.java:150)
        at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:351)
        at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildDefaultMergedContextConfiguration(AbstractTestContextBootstrapper.java:267)
        at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:215)
        at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildTestContext(AbstractTestContextBootstrapper.java:108)
        at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.buildTestContext(SpringBootTestContextBootstrapper.java:111)

Below is the ApplicationTest class:

@SpringBootTest
public class AppserverApplicationTests {

  @Test
  public void contextLoads() {
    // do nothing
  }
}