How to use forCharacter method of org.mockitousage.MethodsImpl class

Use @Spy annotation

@RunWith(MockitoJUnitRunner.class)
public class DemoTest {
    @Spy
    private SomeService service = new RealServiceImpl();

    @InjectMocks
    private Demo demo;

    /* ... */
}

Mockito will consider all fields having @Mock or @Spy annotation as potential candidates to be injected into the instance annotated with @InjectMocks annotation. In the above case 'RealServiceImpl' instance will get injected into the 'demo'

For more details refer

Mockito-home

@Spy

@Mock

Try to use Mockito or Easymock for mocking service calls. You need to mock only these methods which are actually used - no need to mock every method. You can creat mock object for WebResource class, then mock accept method call.

In @BeforeClass/@Before JUnit test method write something like (Mockito example)

WebResource res = mock(WebResource.class);
when(res.accept(something)).thenReturn(thatWhatYouWant);

Then in your tests you can use res object as if it was real object and call mock method on it. Instead of returning value you can also throw exceptions. Mockito is pretty cool.

Mocks that return have the expectation that the return type matches the mocked object's return type.

Here's the mistake:

Mockito.when(remoteStore.get("a", "b")).thenReturn("lol");

"lol" isn't an Optional<String>, so it won't accept that as a valid return value.

The reason it worked when you did

Optional<Object> returnCacheValue = Optional.of((Object) returnCacheValueString);
Mockito.<Optional<Object>>when(remotestore.get("cache-name", "cache-key")).thenReturn(returnCacheValue);

is due to returnCacheValue being an Optional.

This is easy to fix: just change it to an Optional.of("lol") instead.

Mockito.when(remoteStore.get("a", "b")).thenReturn(Optional.of("lol"));

You can also do away with the type witnesses as well. The result above will be inferred to be Optional<String>.

If you are able to set a fixed number of calls to expect, it can be done with an ArgumentCaptor:

import static org.hamcrest.CoreMatchers.hasItem;

@Captor ArgumentCaptor<String> arg;

@Before
public void setUp() throws Exception {
    // init the @Captor
    initMocks(this);
}

@Test
public void testWithTimeoutCallOrderDoesntMatter() throws Exception {
    // there must be exactly 99 calls
    verify(myMock, timeout(5000).times(99)).myMethod(arg.capture());
    assertThat(arg.getAllValues(), hasItem("expectedArg"));
}

Another way is to specify all the expected values to verify, but those need to be provided in the exact order that they are invoked. The difference to the above solution is that this doesn't fail even if the mock is additionally called with some non-verified arguments. In other words, no need to know the number of total invocations. Code example:

@Test
public void testWithTimeoutFollowingCallsDoNotMatter() throws Exception {
    // the order until expected arg is specific
    verify(callback, timeout(5000)).call("firstExpectedArg");
    verify(callback, timeout(5000)).call("expectedArg");
    // no need to tell more, if additional calls come after the expected arg
    // verify(callback, timeout(5000)).call("randomArg");
}

When you are invoking

Mockito.when(spy.isCertainValue()).thenReturn(true);

the method isCertainValue() is getting called here. This is how Java works: to evaluate the argument of Mockito.when, the result of spy.isCertainValue() must be evaluated so the method must be called.

If you don't want that to happen, you can use the following construct:

Mockito.doReturn(true).when(spy).isCertainValue();

This will have the same mocking effect but the method won't be called with this.

Have you installed the Spek plugin for IntelliJ?

Just search for spek in the IntelliJ plugin settings.

The problem seems to be that you are calling a mocked method this.config.apiEndpoint() during the eq ( ... ) invocation. Try to simple put the complete URL in there ( host:port/api/my/specific/url ) instead of calling another mock there, which might confuse Mockito, since it relies on internal states for the mocking.

To be quite honest, I am not that deep into Mockito that I could explain WHY this happens, but I'll probably try to debug into it one day ;-)

Edit: Strangely enough, I seem not to be able to reproduce it with a simpler testcase. There seems to be more here than meets the eye.

This occurs because you are using any() along with a real parameter VehicleCollection.class of type Class<VehicleCollection>.

Change it just like below, and you should be fine:

 when(queryBus.handle(any(VehicleCollection.class), any(GetVehicle.class))).thenAnswer(null);

Mockito explains why:

If you are using argument matchers, all arguments have to be provided by matchers.

E.g: (example shows verification but the same applies to stubbing):

    // Correct - eq() is also an argument matcher
    verify(mock).someMethod(anyInt(), anyString(), eq("third argument"));


    // Incorrect - exception will be thrown because third argument is given without argument matcher.
    verify(mock).someMethod(anyInt(), anyString(), "third argument");    

I'm not sure if your library is stored in a maven repository or not. I assume it is.

I know of two ways of importing a gradle project into IntelliJ. The first being the "Import Project..." wizard from IntelliJ which works nicely. But it does not import the javadoc jars if they exist. At least I never managed it.

The second method uses the idea plugin in gradle 2.1. The plugin generates the project for you. This way I got the javadoc inside. A fully working example for a build.gradle:

apply plugin: 'java'
apply plugin: 'idea'

sourceCompatibility = '1.7'
targetCompatibility = '1.7'

repositories {
    mavenCentral()
}

dependencies {
    compile group: 'org.apache.commons', name: 'commons-compress', version: '1.8.1'
    compile group: 'com.google.guava', name: 'guava', version: '18.0'

    testCompile group: 'junit', name: 'junit', version: '4.11'
    testCompile group: 'org.mockito', name: 'mockito-all', version: '1.8.5'
}

idea{
    project {
        languageLevel = '1.7'
    }
    module {
        downloadJavadoc = true // defaults to false
        downloadSources = true
    }
}

The you can call gradle cleanIdea idea which creates your project for IntelliJ.

If your library is not stored in a maven repository you can simply put up a nexus where you upload it. This would allow you to use the method described above.