EasyMock void method

You’re close.

You just need to call the method on your mock before calling expectLastCall()

So you expectation would look like this:

userService.addUser(newUser1);
EasyMock.expectLastCall();
EasyMock.replay(dbMapper);
userService.addUser(newUser1);

This works because the mock object is in Record mode before the call to replay(), so any calls to it will perform default behaviour (return null/do nothing) and will be eligible for replaying when the replay() method is called.

What I like to do to make sure that it is obvious the method call is for an expectation is to put a small comment in front of it like this:

/* expect */ userService.addUser(newUser1);
EasyMock.expectLastCall();
EasyMock.replay(dbMapper);
userService.addUser(newUser1);