How to use excludes method of org.mockitoutil.ClassLoaders class

Probably, the versions of Powermock and Mockito are not compatible. Fix that and it won't be a n issue anymore.

Mockito                     PowerMock
1.10.8+                     1.6.2+
1.9.5-rc1 - 1.9.5           1.5.0 - 1.5.6
1.9.0-rc1 & 1.9.0           1.4.10 - 1.4.12
1.8.5                       1.3.9 to 1.4.9
1.8.4                       1.3.7 & 1.3.8 
1.8.3                       1.3.6
1.8.1 & 1.8.2               1.3.5
1.8                         1.3
1.7                         1.2.5

See: https://github.com/powermock/powermock/wiki/Mockito#supported-versions

Question might be a bit old but I will put an answer in case someone stumbles across.

• I'm using Mockito and JUnit.
• AccountRepository is a plain spring data repository extending JPARepository.
• Account is a plain JPA entity.

To test your services and mock Spring Data repositories, you need something like below.

package foo.bar.service.impl;

import foo.bar.data.entity.Account;
import foo.bar.data.repository.AccountRepository;
import foo.bar.service.AccountService;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.runners.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class AccountServiceImplTest {

    @Mock
    private static AccountRepository accountRepository;

    @InjectMocks
    private static AccountService accountService = new AccountServiceImpl();

    private Account account;

    @Test
    public void testFindAccount() {

        Integer accountId = new Integer(1);

        account = new Account();
        account.setId(accountId);
        account.setName("Account name");
        account.setCode("Accont code");
        account.setDescription("Account description");

        Mockito.when(accountRepository.findOne(accountId)).thenReturn(account);

        Account retrivedAccount = accountService.findAccount(accountId);

        Assert.assertEquals(account, retrivedAccount);

    }

}

PowerMock implements its own MockMaker which leads to incompatibility with Mockito mock-maker-inline, even if PowerMock is just added as a dependency and not used. If two org.mockito.plugins.MockMaker exist in path then any only one can be used, which one is undetermined.

PowerMock can however delegate calls to another MockMaker, and for then tests are run without PowerMock. Since PowerMock 1.7.0 this can be configured with using the PowerMock Configuration.

The MockMaker can be configured by creating the file org/powermock/extensions/configuration.properties and setting:

mockito.mock-maker-class=mock-maker-inline

Example of using Mockito mock-maker-inline with PowerMock: https://github.com/powermock/powermock-examples-maven/tree/master/mockito2

From the Mockito documentation :

Resetting mocks (Since 1.8.0)

Smart Mockito users hardly use this feature because they know it could be a sign of poor tests. Normally, you don't need to reset your mocks, just create new mocks for each test method. Instead of reset() please consider writing simple, small and focused test methods over lengthy, over-specified tests. First potential code smell is reset() in the middle of the test method. This probably means you're testing too much. Follow the whisper of your test methods: "Please keep us small & focused on single behavior". There are several threads about it on mockito mailing list.

The only reason we added reset() method is to make it possible to work with container-injected mocks.

You should probably just recreate the spy in a @BeforeMethod :

public class Program {

    private TestObject testObject = new TestObject();
    private TestObject spyTestObject;

    @BeforeMethod
    public void buildSpy() {
        spyTestObject = spy(testObject);
    }

    @Test
    public void test1() {
       spyTestObject.makeSth(); 
       verify(spyTestObject , only()).someMethodNeedToBeChecked(); 
    }

    @Test
    public void test2() {
        // Some different scenario
       spyTestObject.makeSth(); 
       verify(spyTestObject , only()).someMethodNeedToBeChecked(); 
        ...
    }
}

You can achieve that with thenAnswer(), a feature Mockito documentation sees as controversial:

Yet another controversial feature which was not included in Mockito originally. We recommend using simple stubbing with toReturn() or toThrow() only. Those two should be just enough to test/test-drive any clean & simple code.

Here's thenAnswer:

private boolean called = false;

when(mock.nextItem()).thenAnswer(new Answer() {
 Object answer(InvocationOnMock invocation) {   
     called = true;       
     return item;
 }
when(mock.isEmpty()).thenAnswer(new Answer() {
 Object answer(InvocationOnMock invocation) {          
     return called;
 }
});

You can use MockRunner, which has support for JDBC. General mocking frameworks like Mockito will also work, but JDBC is a set of interfaces returning each other so hand-mocking will be hard. See for yourself: How to stub/mock JDBC ResultSet to work both with Java 5 and 6?

However mocking JDBC is so brittle and verbose (no matter which tools you use) that I would either suggest abstracting JDBC access within some thin DAO layer (see @duffymo answer) or go for in-memory database like H2.

See also:

• Mock JDBC driver not worth it

It's a bug: https://github.com/spring-projects/spring-boot/issues/6541

The fix is in spring-data 1.0.2-SNAPSHOT and 2.0.3-SNAPSHOT : https://github.com/arangodb/spring-data/issues/14#issuecomment-374141173

If you aren't using these version, you can work around it by declaring the mock with its name:

@MockBean(name="myMongoRepository")
private MyMongoRepository repository;

In response to your comment

From Spring's doc:

For convenience, tests that need to make REST calls to the started server can additionally @Autowire a TestRestTemplate which will resolve relative links to the running server.

Reading this, I think you need to declare @SpringBootTest with a web environment:

@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)

If your spring boot doesn't start the web environment, then what is the need for TestRestTemplate. Thus, I guess spring does not even make it available.

You can also use @InjectMocks annotation, that way you wont need any getters and setters. Just make sure you add below in your test case after annotating your class,

@Before
public void initMocks(){
    MockitoAnnotations.initMocks(this);
}

I found that RxJava provides a class called TestSubject

You can create it like this

private TestScheduler eventsScheduler = new TestScheduler();
private TestSubject<MyEvent> eventObservable = TestSubject.create(eventsScheduler);

This will provide you with the method hasObservers() which returns a boolean.

@Test
public void testSubscription(){
    myTestClass.init(eventObservable);

    assertTrue(eventObservable.hasObservers());
}

Also the TestSubject allows you to perfectly time when events should be sent.

eventObservable.onNext(new MyEvent());
eventsScheduler.triggerActions();