Does anybody know why JUnit 4 provides assertEquals(foo,bar) but not assertNotEqual(foo,bar) methods?
It provides assertNotSame
Usually I do this when I expect two objects to be equal:
assertTrue(obj1.equals(obj2));
and:
assertFalse(obj1.equals(obj2));
when they are expected to be unequal. I am aware that this not an answer to your question but it is the closest I can get. It could help others searching for what they can do in JUnit versions before JUnit 4.11.