Improved support for generic types in 5.2.0

[Jörg von Frantzius]

Hi,

I'm happy that PR Feature 2921 generic types by jfrantzius · Pull Request #2923 · mockito/mockito (github.com) was merged, which provides improved support for generic types with @Mock and @Injection.

Previously, it was easy to step into the trap of adding just another @Mock field with a generic type to your class under test and suddenly see your test fail, without any reasons given. You'd then have to know that your @Mock field has to have the same name as the @InjectMock's field, which non-expert users just aren't aware of. IMHO, this has led to users distrusting @Mock and @InjectMock in general, and simply stop using them, as they failed in common use-cases without any obvious reasons or remedy.

Despite Java's type erasure, Mockito now knows from Java's generic type information where to inject which @Mock field e.g. here:

public class UnderTestWithTypeParameters<T1, T2> {

List<T1> t1List;

List<T2> t2List;

}

@Mock

List<String> stringList;

@Mock

List<Integer> intList;

@InjectMocks

UnderTestWithTypeParameters<String, Integer> underTestWithTypeParameters = new UnderTestWithTypeParameters<String, Integer>();

For more usage examples please see mockito/GenericTypeMockTest.java at main · mockito/mockito · GitHub

The feature is available with Release v5.2.0 · mockito/mockito (github.com), thx TimvdLippe for reviewing + merging.

Cheers,

Jörg