Hacky way of getting a custom GraphQL scalar for raw JSON to work in Apollo iOS

Raw.swift

typealias Raw = [String: JSONDecodable & JSONEncodable]

extension Dictionary: JSONDecodable {
  public init(jsonValue value: JSONValue) throws {
    guard let dictionary = forceBridgeFromObjectiveC(value) as? Dictionary else {
      throw JSONDecodingError.couldNotConvert(value: value, to: Dictionary.self)
    }
    self = dictionary
  }
}

extension Array: JSONDecodable {
  public init(jsonValue value: JSONValue) throws {
    guard let array = forceBridgeFromObjectiveC(value) as? Array else {
      throw JSONDecodingError.couldNotConvert(value: value, to: Array.self)
    }
    self = array
  }
}

// The types we get from `JSONSerialization` are Objective-C implementation types like
// `NSTaggedPointerString`, `__NSCFNumber`, `__NSSingleEntryDictionaryI`, etc.
// and although these get implicitly converted to Swift types in most contexts,
// they don’t allow us to check for protocol conformance.
// That means `NSTaggedPointerString` is not `JSONDecodable` and `JSONEncodable`
// for example, even though `String` is. Force casting to Swift types solves this.
private func forceBridgeFromObjectiveC(_ value: Any) -> Any {
  switch value {
  case is NSString:
    return value as! String
  // Can't use NSNumber here because we don't know whether to bridge to Bool, Int or Double.
  // So instead we have to check possible conversions one by one.
  // This isn't strictly correct because it converts 0 and 1 to Bool for example.
  // See https://bugs.swift.org/browse/SR-5863
  case is Bool:
    return value as! Bool
  case is Int:
    return value as! Int
  case is Double:
    return value as! Double
  case is NSDictionary:
    return Dictionary(uniqueKeysWithValues: (value as! NSDictionary).map { ( $0.key as! AnyHashable, forceBridgeFromObjectiveC($0.value)) })
  case is NSArray:
    return (value as! NSArray).map { forceBridgeFromObjectiveC($0) }
  default:
    return value
  }
}