How can Junit test classes detect classes defined in a kotlin file?

Question

I have a Java gradle project in which i'm using a kotlin file to easily define pojo-like classes on one line. However, when i try to start a junit5 test I get a compile error stating that it can't detect any of the classes defined in the kotlin file. I have the kotlin plugin included in the gradle.build file. How do i get the test classes to detect the classes defined in the kotlin file?

Thank you

Answer 1

If you write JUnit5-tests with Gradle, be sure to have something like the following in place in your build.gradle-(or build.gradle.kts)-file, so that Gradle also knows that it should use the JUnit5-platform (compare also JUnit 5 User Guide - Build support - Gradle ):

tasks.withType<Test> {
  useJUnitPlatform()
}

Moreover also ensure that the annotation you use is the following:

org.junit.jupiter.api.Test

and not the one of JUnit4, ie org.junit.Test . If you have that one, you probably want to remove the junit4-dependency altogether.