How to extend a type from on subgraph into another

[rquackenbush]

What

I'm trying to extend another type using GraphQL federation under using the following syntax:

[Key("id")]
[Extends]
public class Parent
{
    [ID]
    public string Id { get; set; }

    public List<Child> Children()
    {
        return new List<Child>
        {
            new Child("1", "Child 1"),
            new Child("2", "Child 2")
        };
    }
}

And the following registration code:

   .AddTypeExtension<Parent>()

Is what I'm trying to do possible? If so, what am I doing wrong?

Repro

I have created a minimal reproduction of my scenario here: https://github.com/rquackenbush/apollo-federation-repro

[dariuszkuc]

Hello 👋 Each subgraph declares Parent as its own type -> there is no need for [Extends] directive marker (it was required for fed v1 it is not needed for v2) nor registering any type extensions. From subgraph perspective it is just a regular type that has some extra directives applied to it. Those extra directives are then used by the composition process to compose your supergraph.

FYI since Parent type is an entity, you also need to register the entity resolvers -> see our README and/or HotChocolate docs. You can also take a look at the examples in this repo.

For more details about Federation and entities refer to our docs. We also have tutorials about .NET/HotChocolate and Federation -> intro and federation that covers those topics in detail.

[rquackenbush]

Thank you for the push in the right direction! I've updated my example and it's now working.