apollo-ios: Crash when gets new interface type from server

Version

• ApolloClient 0.14.0

Problem

when I have the following types:

interface Notification {
  id: ID!
}

type NotificationArticle implements Notification {
  id: ID!
  article: Article!
}

type NotificationComment implements Notification {
  id: ID!
  comment: Comment!
}

and my app use query from this fragment.

fragment NotificationFragment on Notification {
  id
  ... on NotificationArticle {
    ... ArticleFragment
  }
  ... on NotificationComment{
    ... CommentFragment
  }
}

Later, I add another implementation of Notification below

type NotificationShare implements Notification {
  id: ID!
  share: Share!
}

Without updating app with the new schema, my app will crash when I tried to read id from NotificationShare. The crash happens in generated API.swift below

public var id: GraphQLID {
 get {
  return resultMap["id"]! as! GraphQLID
 }
 set {
   resultMap.updateValue(newValue, forKey: "id")
 }
}

It seems that Apollo Core doesn’t read any field from response when __typename is not exist in fragment’s possible types below (from GraphQLExecutor.swift)

if let runtimeType = runtimeType, fragment.possibleTypes.contains(runtimeType) {
  try collectFields(selections: fragment.selections, forRuntimeType: runtimeType, into: &groupedFields, info: info)
}

Expected Behavior

The app should not crash because id is a field in Notification interface.