Mockito.any() pass Interface with Generics
JavaGenericsMockitoJava Problem Overview
is it possible to pass the type of an interface with generics?
The interface:
public interface AsyncCallback<T>
In my test method:
Mockito.any(AsyncCallback.class)
Putting <ResponseX>
behind or for .class
didnt work.
Java Solutions
Solution 1 - Java
There is a type-safe way: use ArgumentMatchers.any()
and qualify it with the type:
ArgumentMatchers.<AsyncCallback<ResponseX>>any()
Solution 2 - Java
Using Java 8, you can simply use any()
(assuming static import) without argument or type parameter because of enhanced type inference. The compiler now knows from the target type (the type of the method argument) that you actually mean Matchers.<AsyncCallback<ResponseX>>any()
, which is the pre-Java 8 solution.
Solution 3 - Java
I had to adopt the following mechamism to allow for generics:
import static org.mockito.Matchers.any;
List<String> list = any();
when(callMyMethod.getResult(list)).thenReturn(myResultString);
Hope this helps someone.
Solution 4 - Java
Posting pierrefevrier comment as answer which might be useful if it present in a answer instead of comments.
With new versions of Mockito: (Matchers.<AsyncCallback<ResponseX>>any()
Solution 5 - Java
Further to thSoft's answer putting the qualified call to any() in method meant I could remove the qualification since the return type allowed inference:
private HashMap<String, String> anyStringStringHashMap() {
return Matchers.any();
}
Solution 6 - Java
You can just cast it, adding suppress warnings if you like:
@SuppressWarnings("unchecked")
AsyncCallback<ResponseX> callback = Mockito.any(AsyncCallback.class)
If Java allowed 'generic' generics they could have a method like this which is what you are looking for
private static <T, E> T<E> mock(Class<T<E>> clazz)
Solution 7 - Java
I had a similar problem using Spring Example
:
Mockito.when(repo.findAll(Mockito.<Example<SrvReqToSupplierComment>>any()))
.thenReturn(Lists.emptyList());
Here, you have to use qualification, b/c findAll method can take multiple types, like Sort
and Iterable
. You can also use Mockito.any(Example.class)
of course with the type safety warning.
Solution 8 - Java
Using a qualified generics type with the no-argument any()
method works (i.e. ArgumentMatchers.<AsyncCallback<ResponseX>>any()
), but can get unwieldy for longer generics expressions. An alternative is to put a no-argument any()
call in its own generic method, using the specific generic type as the return type:
private static <T> AsyncCallback<T> anyAsyncCallback() {
return ArgumentMatchers.any()
}
Usage
Mockito.verify(mockObject).performCallback(any(), anyAsyncCallback())