Mockito VS RMock

I was asked to provide some comparison with RMock library. I was never an RMock user so the comparison may not be perfect. Don't hesitate to give feedback.

Also, bear in mind that this is just a syntax-wise comparison. Mockito is actually a spying framework disguised into a mocking framework. This means that there is a big difference in the style of testing. You can read more about it on Mockito pages or on Szczepan's blog.

Verifying the method was called

//RMock:
Runnable runnable = (Runnable)mock(Runnable.class);
runnable.run();
startVerification();
//run

//Mockito:
Runnable runnable = mock(Runnable.class);
//run
verify(runnable).run();

• RMock seems to be very similar to EasyMock, it also uses Record/Playback pattern
• RMock has additional testing features that can be used for state testing. E.g: assertThat syntax similar to Hamcrest. Mockito uses hamcrest.

Setting return value

//RMock:
mock.getStuff();
modify().returnValue(stuff);
startVerification();
//run

//Mockito:
when(mock.getStuff()).thenReturn(stuff);
//run

Called at least once

//RMock
runnable.run()
modify().multiplicity(expect.atLeastOnce());
startVerification();
//run

//Mockito:
//run
verify(runnable, atLeastOnce()).run();

Flexible argument matching

//RMock:
mock.twoArguments("anything", someObj);
modify().args(is.ANYTHING, is.AS_RECORDED);
startVerification();
//run

//Mockito:
//run
verify(mock).twoArguments(anyString(), eq(someObj));

Void method to throw

//RMock:
runnable.run();
modify().throwException(exc);
startVerification();
//run

//Mockito:
doThrow(exc).when(runnable).run();
//run