How to use getMethodName method of org.mockito.internal.stubbing.answers.InvocationInfo class

The alternative is to use the @Mock annotation since then Mockito can use type reflection to find the generic type:

public class MyTest {

  @Mock
  private ArrayList<String> mockArrayList;

  ...

  public void setUp() {
    MockitoAnnotations.initMocks(this);
  }

  public void testMyTest() {
    when(mockArrayList.get(0)).thenReturn("Hello world");

    String result = mockArrayList.get(0);

    assertEquals("Should have the correct string", "Hello world", result);

    verify(mockArrayList).get(0);
  }
}

If isSkipped() is not a final method, this problem probably indicates that you try to stub a method while stubbing of another method is in progress. It's not supported because Mockito relies on order of method invocations (when(), etc) in its stubbing API.

I guess you have something like this in your test method:

when(...).thenReturn(getSkippedBuild());

If so, you need to rewrite it as follows:

DynamicBuild build = getSkippedBuild();
when(...).thenReturn(build);

I think you do need to cast it, but it shouldn't be too bad:

Foo<Bar> mockFoo = (Foo<Bar>) mock(Foo.class);
when(mockFoo.getValue()).thenReturn(new Bar());

"Mock" your repository method calls. Also, use @InjectMocks instead @Autowired for TransactionService. And you can also use MockitoJUnitRunner. How to mock repository calls:

when(customerRepository.save(sender)).thenReturn(someSenderInstance);

To verify that mocked method call has been invoked use:

verify(customerRepository, times(1)).save(sender);

Also, remember one thing: You are testing services! Therefore, all calls to database should be mocked.

I also faced the same problem.

And finally, I found argThat() will return null, and normally the argument in the function in kotlin, does not accept null type.

The source code of argThat from ArgumentMatchers.java

public static <T> T argThat(ArgumentMatcher<T> matcher) {
    reportMatcher(matcher);
    return null;
}

You can see that it return null. So when we mock the function, it will throw IllegalStateException, because argThat returns null and argument can't be null.

It mean that if your function is:

fun doSomething(arg1: String): Int {
    // do something
}

When you mock it like that:

Mockito.`when`(
    doSomething(Mockito.argThat<String> { true })
).thenReturn(100)

It will throw IllegalStateException

So you should change your function like that:

fun doSomething(arg1: String?): Int {
    // do something
}

Change the "String" to "String?", make it accept null type.

My solution is to define the argument with class? so that it can accept null, but I don't know if it is a great solution

Make sure you add @RunWith(PowerMockRunner.class) to the top of your class as well.

::edit:: two years later...

Don't ever use PowerMockito, you shouldn't need to.

If you do need to, you have most likely broken the SOLID principles and your design is wrong.

Fix your design instead.

Updating Plugin to version 0.13.3 fixes this issue.

if you do a employee = new Employee(param1, param2); you may as well skip @InjectMocks.

It is supposed to do the following:

@InjectMocks
ClassUnderTest cut;

@Mock
Dependency1 dep1;
@Mock
Dependency2 dep2;

@Before
public void setup() {
  initMocks(this);
}

omitting @InjectMocks the same behaviour can be achieved with the following code:

ClassUnderTest cut;

@Mock
Dependency1 dep1;
@Mock
Dependency2 dep2;

@Before
public void setup() {
  initMocks(this);
  cut = new ClassUnderTest(dep1, dep2);
}

In your specific case, you should mock param1 and param2. Never call the constructor manually when using @InjectMocks.

Mockito isn't good at matching generics itself, but your solution is much easier than the general case.

Replace your:

Matchers.<ParameterizedTypeReference<SearchResultsDTO<SolrDocumentDTO>>>any())

with:

eq(new ParameterizedTypeReference<SearchResultsDTO<SolrDocumentDTO>>() {}))

First of all, Matchers.any() doesn't match type, not even in its any(Foo.class) variety (as of Mockito 1.x). any() matches all values, including null and including incorrect types:

Matches any object, including nulls

This method doesn't do type checks with the given parameter, it is only there to avoid casting in your code. This might however change (type checks could be added) in a future major release.

(The "future major release" may come true for Mockito 2, where isA-style type checks may be introduced. ; See commentary from Mockito committer Brice.)

The generics are helpful to get the right parameter for exchange and thenReturn, but because of type erasure none of that type information makes it into the CLASS file, let alone the JVM. The only Matcher that asserts the type of its argument is isA, which takes a class literal and won't help you for parameterized types.

You could write a custom Matcher that inspects an argument's type and type parameters, if they aren't subject to erasure, but for your specific case that's not necessary.

Type erasure is the whole reason ParameterizedTypeReference exists: It captures the generics information into a subclass, where the parameterized type will not be erased. This same pattern is used for TypeToken in Guava or TypeLiteral in Guice. All of these implementations describe a parameterized type as an instance.

Importantly, all of them—including ParameterizedTypeReference—support equals and hashCode, so new ParameterizedTypeReference<A<B>>(){} equals new ParameterizedTypeReference<A<B>>(){} even though the instances are different. (See the code here.)

Because references to the same parameterized type are equal, use Mockito's eq matcher with a different reference, and things should be fine.