How can I stub a method such that when given a value I'm not expecting, it returns a default value?
For example:
Map<String, String> map = mock(Map.class);
when(map.get("abcd")).thenReturn("defg");
when(map.get("defg")).thenReturn("ghij");
when(map.get(anyString())).thenReturn("I don't know that string");
Part 2: As above but throws an exception:
Map<String, String> map = mock(Map.class);
when(map.get("abcd")).thenReturn("defg");
when(map.get("defg")).thenReturn("ghij");
when(map.get(anyString())).thenThrow(new IllegalArgumentException("I don't know that string"));
In the above examples, the last stub takes precedence so the map will always return the default.
The best solution I have found is to reverse the order of the stubs:
Map<String, String> map = mock(Map.class);
when(map.get(anyString())).thenReturn("I don't know that string");
when(map.get("abcd")).thenReturn("defg");
when(map.get("defg")).thenReturn("ghij");
When the default is to throw an exception you can just use doThrow and doReturn
doThrow(new RuntimeException()).when(map).get(anyString());
doReturn("defg").when(map).get("abcd");
doReturn("ghij").when(map).get("defg");
https://static.javadoc.io/org.mockito/mockito-core/2.18.3/org/mockito/Mockito.html#12