Using Mockito on one test method making other Test methods fail

Question

I am working on creating integration test for a service class i am testing and I needed to mock the dao for one of the test methods. the problem is when i run the tests together some of my tests fail but when i run them individually the tests past. If i remove the mockito part all my tests pass when i run them all at once. any insight on this is appreciated

below is my code:

 // here is my Service class
 public class Service {

 Dao dao;

 public Dao getDao() {
    return dao;
}

public void setDao(Dao dao) {
    this.dao = dao;
}
}

//here is my integ test

@Category(IntegrationTest.class)
@RunWith(SpringRunner.class)
public class Test{

@Rule
public ExpectedException thrown = ExpectedException.none();

@Autowired
@Qualifier(Service.SERVICE_NAME)
protected Service service;

@Before
public void setUp() {
    assertNotNull(service);
}

@Test
public void testDoSomethingOne() throws Exception {
    Dao dao = Mockito(Dao.class)
    service.setDao(dao)
    boolean flag = service.doSomething();
    Assert.assertTrue(flag);
}

@Test
public void testDoSomethingTwo() throws Exception {

    Integer num = service.doSomething();
    Assert.assertNotNull(num);
}

Answer 1

The test method testDoSomethingOne() sets the mock dao for the service instance which it retains for rest of the tests.

Annotate the method testDoSomethingOne() with @DirtiesContext to get a fresh context associated with the subsequent test method.

Test annotation which indicates that the ApplicationContext associated with a test is dirty and should therefore be closed and removed from the context cache.

Use this annotation if a test has modified the context — for example, by modifying the state of a singleton bean, modifying the state of an embedded database, etc. Subsequent tests that request the same context will be supplied a new context.

Answer 2

You can get the dao before each test and assign it back to service after the test something like this:

private static Dao dao;

@Before
public void setUp() {
    if(dao == null) {
       dao = service.getDao();
    }
}

@After
public void tearDown() {
     service.setDao(dao);
}

Answer 3

If it is a integration test you should not mock your daos, the recommended way is to use a in memory database like H2 . The spring folks already provide the annotation @DataJpaTest that creates the database for you.

You can use the @DataJpaTest annotation to test JPA applications. By default, it scans for @Entity classes and configures Spring Data JPA repositories. If an embedded database is available on the classpath, it configures one as well. Regular @Component beans are not loaded into the ApplicationContext.

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-testing-spring-boot-applications-testing-autoconfigured-jpa-test