How to get a JsonProcessingException using Jackson

Question

Might be a strange question but indeed I would like to achieve a a bit more coverage on my tests and although I coded against a JsonProcessingException I can\'t

Answer 1

Building off of Liam's answer, mocking the toString() method with a cycle also causes Jackson to break.

@Test
public void forceJsonParseException() {
    try {
        Object mockItem = mock(Object.class);
        when(mockItem.toString()).thenReturn(mockItem.getClass().getName());
        new ObjectMapper().writeValueAsString(mockItem);
        fail("did not throw JsonProcessingException");
    } catch (JsonProcessingException e) {
        //pass
    }
}

EDIT: It's way easier than that. A Mockito mock will always throw it. o.o;;