Stubs v2

TestUserServiceV2.java

public class TestUserServiceV2 {

	private static final Email EMAIL = new Email("user@company.com");

	private final class StubUserDAOv2 implements UserDAO {
		private User user;

		public User findUserBy(Email email) {
			return user;
		}

		public void setUserFoundByEmail(User user) {
			this.user = user;
		}
	}

	private StubUserDAOv2 stubUserDAO;
	private UserService userService;

	@Before
	public void initialization() {
		stubUserDAO = new StubUserDAOv2();
		userService = new UserService(stubUserDAO);
	}

	@Test
	public void //
	should_throw_exception_when_passwords_are_different_version1() throws Exception {

		stubUserDAO.setUserFoundByEmail(userWithPassword("password"));

		try {
			userService.signIn(EMAIL, new Password("password"));
			fail("No threw exception");
		} catch (AuthenticationException e) {
			// ok
		}
	}

	@Test(expected = AuthenticationException.class)
	public void //
	should_throw_exception_when_passwords_are_different_version2() throws Exception {

		stubUserDAO.setUserFoundByEmail(userWithPassword("another_password"));

		userService.signIn(EMAIL, new Password("password"));
	}

	private User userWithPassword(String password) {
		return aUser() //
		        .password(password) //
		        .build();
	}
}

UserService.java

public class UserService {

	private UserDAO userDAO;

	public UserService(UserDAO userDAO) {
		this.userDAO = userDAO;
	}

	public User signIn(Email email, Password password) throws AuthenticationException {
		User user;

		user = userDAO.findUserBy(email);
		// validation user
		if (!password.is(user.getPassword())) {
			throw new AuthenticationException("user has no permission");
		}
		// do something
		return user;
	}
}