Injecting mock @Service for Spring unit tests

Question

I am testing a class that uses use @Autowired to inject a service:

public class RuleIdValidator implements ConstraintValidator<ValidRuleId, String> {

    @Autowired
    private RuleStore ruleStore;

    // Some other methods
}

But how can I mock ruleStore during testing? I can't figure out how to inject my mock RuleStore into Spring and into the Auto-wiring system.

Thanks

Answer 1

It is quite easy with Mockito:

@RunWith(MockitoJUnitRunner.class)
public class RuleIdValidatorTest {
    @Mock
    private RuleStore ruleStoreMock;

    @InjectMocks
    private RuleIdValidator ruleIdValidator;

    @Test
    public void someTest() {
        when(ruleStoreMock.doSomething("arg")).thenReturn("result");

        String actual = ruleIdValidator.doSomeThatDelegatesToRuleStore();

        assertEquals("result", actual);
    }
}

Read more about @InjectMocks in the Mockito javadoc or in a blog post that I wrote about the topic some time ago.

Available as of Mockito 1.8.3, enhanced in 1.9.0.