Is there a simpler/better way to write the following?

@Mock Dog dog; // Dog is a record

when(dog.tail()).thenReturn(Optional.empty);
when(dog.paw()).thenReturn(Optional.empty);
when(dog.nose()).thenReturn(Optional.empty);
when(dog.eye()).thenReturn(Optional.empty);
..

Is there a simpler/better way to write the following?

@Mock Dog dog; // Dog is a record

when(dog.tail()).thenReturn(Optional.empty);
when(dog.paw()).thenReturn(Optional.empty);
when(dog.nose()).thenReturn(Optional.empty);
when(dog.eye()).thenReturn(Optional.empty);
..

• java
• mockito
• stubbing

2 Answers 2

@Mock
Dog dog; // Dog is a record

doReturn(Optional.empty())
    .when(dog).tail()
    .when(dog).paw()
    .when(dog).nose()
    .when(dog).eye();

You can create a helper function that will stub all of the methods with the same return value:

import static .mockito.Mockito.*;

@Mock
Dog dog; // Dog is a record

private void mockDogMethods() {
    // List of method names
    List<String> methodsToMock = List.of("tail", "paw", "nose", "eye");

    methodsToMock.forEach(method -> 
        when(dog.getClass().getMethod(method).invoke(dog)).thenReturn(Optional.empty())
    );
}

// Use the helper in your test setup
mockDogMethods();