Don't print empty braces when input object has no arguments

lib/graphql/language/printer.rb

@@ -236,12 +236,15 @@ def print_input_object_type_definition(input_object_type)
         out = print_description(input_object_type)
         out << "input #{input_object_type.name}"
         out << print_directives(input_object_type.directives)
-        out << " {\n"
-        input_object_type.fields.each.with_index do |field, i|
-          out << print_description(field, indent: '  ', first_in_block: i == 0)
-          out << "  #{print_input_value_definition(field)}\n"
+        if !input_object_type.fields.empty?
+          out << " {\n"
+          input_object_type.fields.each.with_index do |field, i|
+            out << print_description(field, indent: '  ', first_in_block: i == 0)
+            out << "  #{print_input_value_definition(field)}\n"
+          end
+          out << "}"
         end
-        out << "}"
+        out
       end
 
       def print_directive_definition(directive)

spec/graphql/schema/printer_spec.rb

@@ -70,6 +70,9 @@ class Media < GraphQL::Schema::Union
     class NoFields < GraphQL::Schema::Object
     end
 
+    class NoArguments < GraphQL::Schema::InputObject
+    end
+
     class Query < GraphQL::Schema::Object
       description "The query root of this schema"
 
@@ -80,7 +83,9 @@ class Query < GraphQL::Schema::Object
         argument :deprecated_arg, String, required: false, deprecation_reason: "Use something else"
       end
 
-      field :no_fields_type, NoFields
+      field :no_fields_type, NoFields do
+        argument :no_arguments_input, NoArguments
+      end
     end
 
     class CreatePost < GraphQL::Schema::RelayClassicMutation
@@ -531,6 +536,8 @@ class Subscription < GraphQL::Schema::Object
   ): CreatePostPayload
 }
 
+input NoArguments
+
 type NoFields
 
 interface Node {
@@ -552,7 +559,7 @@ class Subscription < GraphQL::Schema::Object
 The query root of this schema
 """
 type Query {
-  noFieldsType: NoFields
+  noFieldsType(noArgumentsInput: NoArguments!): NoFields
   post(
     deprecatedArg: String @deprecated(reason: "Use something else")
 
@@ -721,6 +728,8 @@ def foobar
   ): CreatePostPayload
 }
 
+input NoArguments
+
 type NoFields
 
 interface Node {
@@ -741,7 +750,7 @@ def foobar
 The query root of this schema
 """
 type Query {
-  noFieldsType: NoFields
+  noFieldsType(noArgumentsInput: NoArguments!): NoFields
   post(
     """
     Post ID