Delay input type validation for late-bound types

Author: rmosolgo

lib/graphql/schema/argument.rb

@@ -146,7 +146,10 @@ def to_graphql
         argument
       end
 
-      attr_writer :type
+      def type=(new_type)
+        validate_input_type(new_type)
+        @type = new_type
+      end
 
       def type
         @type ||= begin
@@ -155,10 +158,7 @@ def type
           rescue StandardError => err
             raise ArgumentError, "Couldn't build type for Argument #{@owner.name}.#{name}: #{err.class.name}: #{err.message}", err.backtrace
           end
-          unwrapped_parsed_type = parsed_type.unwrap
-          if !unwrapped_parsed_type.kind.input?
-            raise ArgumentError, "Invalid input type for #{path}: #{unwrapped_parsed_type.graphql_name}. Must be scalar, enum, or input object, not #{unwrapped_parsed_type.kind.name}."
-          end
+          validate_input_type(parsed_type)
           parsed_type
         end
       end
@@ -195,6 +195,18 @@ def prepare_value(obj, value, context: nil)
           raise "Invalid prepare for #{@owner.name}.name: #{@prepare.inspect}"
         end
       end
+
+      def validate_input_type(input_type)
+        if input_type.is_a?(String) || input_type.is_a?(GraphQL::Schema::LateBoundType)
+          # Do nothing; assume this will be validated later
+        elsif input_type.kind.non_null? || input_type.kind.list?
+          validate_input_type(input_type.unwrap)
+        elsif !input_type.kind.input?
+          raise ArgumentError, "Invalid input type for #{path}: #{input_type.graphql_name}. Must be scalar, enum, or input object, not #{input_type.kind.name}."
+        else
+          # It's an input type, we're OK
+        end
+      end
     end
   end
 end