org.openrewrite.java.testing.junit5.AddMissingNested recipe adds @Nested to abstract classes and ignores effectively-@Nested subclasses that don't have their own @Test methods but inherit some from their superclasses.

@Nested on abstract class causes java.lang.InstantiationException at runtime.
See junit-team/junit-framework#2717, or junit-team/junit-framework#2717 (comment) more specifically for explanation.

Missing @Nested on a class which doesn't have its own @Test methods but inherits @Test methods from its possible abstract superclasses leads to missed tests - this non-annotated class will not be detected by JUnit 5.

What version of OpenRewrite are you using?

• rewrite-maven-plugin 6.11.0
• rewrite-testing-frameworks 3.10.0

What is the smallest, simplest way to reproduce the problem?

import org.junit.jupiter.api.Test;

public class AddMissingNestedTest {

    abstract class CommonNestedBase {
        @Test
        void commonNestedTest() {
        }
    }

    class NestedTest extends CommonNestedBase {
    }

}

What did you expect to see?

import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

public class AddMissingNestedTest {

    abstract class CommonNestedBase {
        @Test
        void commonNestedTest() {
        }
    }

    @Nested
    class NestedTest extends CommonNestedBase {
    }

}

What did you see instead?

import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

public class AddMissingNestedTest {

    @Nested
    abstract class CommonNestedBase {
        @Test
        void commonNestedTest() {
        }
    }

    class NestedTest extends CommonNestedBase {
    }

}

Are you interested in contributing a fix to OpenRewrite?

Seems like the case with adding @Nested to abstract class can be solved by adding the corresponding check near https://github.com/openrewrite/rewrite-testing-frameworks/blob/main/src/main/java/org/openrewrite/java/testing/junit5/AddMissingNested.java#L90.

Right now I am not sure how to approach the case with nested test class without test methods that inherits test methods for some of its superclasses.