Projections do not support generics

[alienisty]

I don't know if it by design, but projections do not (properly?) support generics. For example, if I have:

public interface GenericCollectionSummary<E> {
	List<E> getMembers();
}

interface SpecialisedProjection extends GenericProjection<ValueProjection> {
}

Then the resulting JSON will not represent values as ValueProjection, but as the JSON format for its backing type.

So if we have:

class Person {
  String name;
  String surname;
  String getName(){}
  String getSurname(){}
}

class Club {
  List<Person> members;
  List<Person> getMembers(){}
}

and

@Projection(name = "summary", types = Person.class)
interface PersonSummary {
  @Value("#{target.name + ' ' + target.surname}")
  String getFullName();
}

@Projection(name = "summary", types = Club.class)
public interface ClubSummary extends GenericCollectionSummary<PersonSummary> {
}

So given a list of clubs using such projection such as { members: [{name: 'John', surname: 'Doe'}] }, you'll get the following projection:

{
  "values": [
    {
      "name": "John",
      "surname": "Doe"
    }
  ]
}

rathern than the expected:

{
  "values": [
    {
      "fullName": "John Doe"
    }
  ]
}

See attached demo for a runtime demonstration.

[mp911de]

If you would like us to spend some time helping you to diagnose the problem, please spend some time describing it and, ideally, providing a minimal sample that reproduces the problem. Please let us know in which context you're using projections (repositories, custom controller methods, …) so we can understand the use case.

[alienisty]

Sorry about that, I had to draft quickly bicause of time constraints and I didn't want to forget it. I've improved the description.

Also, here is an example demonstrating the issue demo.zip

[alienisty]

Any update on this one?