Drops Encodable requirement on GraphQL types

[NeedleInAJayStack]

This drops unnecessary Codable conformance from GraphQL-injected types. More specifically, output types are never encoded or decoded - only the resulting leaf Scalars are encoded. While this PR removes the restriction that all output types are codable, it still requires Encodability on Scalars and Decodability on Arguments. Decodable conformance is technically removed from Input objects, but typically still enforced through the decodable Argument requirement.

This change is useful if you have a complex, non-codable type that you would like to pass through resolver chains.

[NeedleInAJayStack]

Changing to draft. It turns out that the Encodable conformance was the only thing differentiating SyncResolve and SimpleAsyncResolve. Without it, resolvers that return futures match both signatures, meaning that the Field init is ambiguous.

[cshadek]

Would this make connections of interfaces/unions possible?

[NeedleInAJayStack]

Would this make connections of interfaces/unions possible?

I don't think so. I think that's more a limitation in how the GraphQL type system is implemented than a Swift codability restriction.

[cshadek]

My understanding is the only reason connections of interfaces/ unions doesn't work is that node needs to be encodable. I've created custom connections where the a swift protocol is the node.

[paulofaria]

@NeedleInAJayStack have you tried @_disfavoredOverload?

[NeedleInAJayStack]

@NeedleInAJayStack have you tried @_disfavoredOverload?

@paulofaria OMG, you're a genius! I had no idea that existed and it totally fixed the problem. Thanks!

[NeedleInAJayStack]

My understanding is the only reason connections of interfaces/ unions doesn't work is that node needs to be encodable. I've created custom connections where the a swift protocol is the node.

@cshadek Oh okay! Yeah, if that's the case, then this probably will fix it!

[NeedleInAJayStack]

This is super awesome! I'm just curious as to why a type would not be able to conform to Codable. 😄

😆 It's a good question... My primary use case is that I have an object with a property that contains existentials, which makes it pretty hard to decode without a huge typeswitch. I don't really want to expose this property in GraphQL, but I do want to expose things derived from it. For example:

struct A {
  let b: [any B] // Not exposed in GraphQL, but important to keep around.
  var bDescription: String { // Exposed in GraphQL
    return b.map { $0.description }
  }
}

[paulofaria]

Gotcha, makes sense! Just out of curiosity, 😄. Are you using an existential because the array is not homogeneous so generics wouldn't work?

[NeedleInAJayStack]

Yeah, exactly. It's a heterogeneous array.