In the advice of Mockito about how to write good tests, it is written that we should not mock value objects (https://github.com/mockito/mockito/wiki/How-to-write-good-tests#dont-mock-value-objects). They even say

Because instantiating the object is too painful !? => not a valid reason.

But I don’t understand. What if we really don’t care about what that object contain? Let’s just say that I have a value object class “Foo” that doesn’t have simple constructors (it has an all-args constructor and contains objects that also need all-args constructors). Let’s also say I have the following service:

public class MyService {     private SomeService someService;     private OtherService otherService;      public void myAwesomeMethod() {         Foo foo = someService.getFoo();         someOtherService.doStuff(foo);     } } 

And I need to test that method. Clearly here I don’t care about what foo contains because I just pass it to another method. If I want to test it should I really create a foo object with nested constructors/builders? For me it would be really easy to mock foo even if it is a POJO :

public class MyServiceTest {     @InjectMocks     MyService myService;      @Mock     private SomeService someService;      @Mock     private OtherService otherService;      @Test     public void testMyAwesomeMethod() {         Foo mockedFoo = Mockito.mock(Foo.class);          Mockito.when(someService.getFoo()).thenReturn(mockedFoo);          Mockito.verify(otherService).doStuff(mockedFoo);     }  } 

But then it wouldn’t respect the guidelines given by Mockito. Is there another alternative?