Root query: generate {x}Option method for fields with an optional interface type

[iRevive]

ClientWriter does not handle optional interfaces properly of the root query.

I fixed the processing of the root query in the scope of the PR. If the output type of a field is an interface, the ClientWriter will generate two methods: def {x}(...) and def {x}Option(...).

Schema 1 (without root schema)

type Queries {
  node(id: ID!): Node
}
interface Node {
  id: ID!
}
type NodeA implements Node {
  id: ID!
  a: String
}
type NodeB implements Node {
  id: ID!
  b: Int
}

ClientWriter generates two methods: node(id: ID)(...) and nodeOption(id: ID)(...).

Schema 2 (with top-level schema definition)

+ schema {
+  query: Queries
+}
type Queries {
  node(id: ID!): Node
}
interface Node {
  id: ID!
}
type NodeA implements Node {
  id: ID!
  a: String
}
type NodeB implements Node {
  id: ID!
  b: Int
}

ClientWriter generates only one method: node(id: ID)(...).

[ghostdogpr]

Looks good! Shouldn't the same thing be applied to mutations and subscriptions?

[iRevive]

Good point. I guess mutations and subscriptions should be updated as well. I will push an update soon.

[iRevive]

Done

[ghostdogpr]

Thanks!