mockito anyList of a given size

Question

I\'m verifying with mockito that a method has been called. The method:

public void createButtons(final List buttonsConfiguration) {...}
         


        

Answer 1

One way is to use a Captor

ArgumentCaptor captor = ArgumentCaptor.forClass(List.class);
verify(mock).createButtons(captor.capture());
assertEquals(x, captor.getValue().size()); // or if expecting multiple lists:
assertEquals(x, captor.getValues().size());

See http://docs.mockito.googlecode.com/hg/org/mockito/Mockito.html#15 for the documentation.

You could also use a custom argument matcher. The documentation shows an example that does exactly what you want:

http://docs.mockito.googlecode.com/hg/org/mockito/ArgumentMatcher.html

 class IsListOfTwoElements extends ArgumentMatcher {
     public boolean matches(Object list) {
         return ((List) list).size() == 2;
     }
 }

 List mock = mock(List.class);
 when(mock.addAll(argThat(new IsListOfTwoElements()))).thenReturn(true);
 mock.addAll(Arrays.asList("one", "two"));
 verify(mock).addAll(argThat(new IsListOfTwoElements()));

You could, for instance, also add a constructor so you can specify list size desired, etc.