Test Lombok's @UtilityClass auto-generated code

Question

I have a class that's annotated with @UtilityClass like this

@UtilityClass
public class myUtilClass {
...
}

JaCoCo doesn't give me full coverage for this class because of the auto-generated code created by the annotation @UtilityClass . Ideally, I do not want to change any config files to ignore auto-gen code. How can this code be tested?

Answer 1

Just write this unit test to ensure your class cannot be instantiated because of @UtilityClass annotation. Then, coverage will be OK.

@Test
  void test_cannot_instantiate() {
    assertThrows(InvocationTargetException.class, () -> {
      var constructor = YOUR_CLASS_NAME.class.getDeclaredConstructor();
      assertTrue(Modifier.isPrivate(constructor.getModifiers()));
      constructor.setAccessible(true);
      constructor.newInstance();
    });
  }