__resolveType receiving Promise after __resolveReference for interfaces

[jhanggi]

Issue Description

When using __resolveReference to resolve an interface, it ends up passing a promise to __resolveType. It is my understanding that while __resolveType can return a promise, it should not receive a promise.

In my example, if I take out the __resolveType, I get an expected error about needing to implement __resolveType or isTypeOf. If I make the __resolveReference synchronous, everything works fine. But if it's async (like it would be if it hit an actual database), then the type of the object going into __resolveType is a promise which means that it won't match any of my conditionals.

I was able to make a codesandbox with this issue. I was originally trying to do this with typegraph, but when I ran into the issue, I decided to take that out of the equation and came up with this. I have a PR over there as well: MichalLytek/type-graphql#1448

Link to Reproduction

https://codesandbox.io/p/sandbox/naughty-keldysh-phhss6?file=%2Fsrc%2Fproducts.ts

Reproduction Steps

I've set it up so "Product" is an interface for Books and Movies.

Run this of :4000 (the supergraph):

query ExampleQuery {
  reviews {
    id
      product {
        id
        name
        __typename
        ... on Book {
          author
        }
        ... on Movie {
          director
        }
      }
  
  }
}

You can also run the reference resolution query directly on the products subgraph (:4001):

query ($representations: [_Any!]!) {
    _entities(representations: $representations) {
      ... on Product {
        name
      }
    }
  }

variable:
{"representations": [{"__typename": "Product", "id": "1"}]}

[trevor-scheer]

This seems like a legitimate issue (if it's not then we surely must have another way of accomplishing what you're after). I've opened a PR with a reproduction and a proposed fix, I'll surface it to the team. Thanks for taking the time to put together a reproduction!

[jhanggi]

I've upgrade to subgraph 2.4.5 and that fixes our issue. Thanks!