Add support for directives

lib/graphql/language/nodes.rb

@@ -373,7 +373,7 @@ class DirectiveLocation < NameOnlyNode
       end
 
       class DirectiveDefinition < AbstractNode
-        attr_reader :description
+        attr_reader :comment, :description
         scalar_methods :name, :repeatable
         children_methods(
           arguments: Nodes::Argument,

lib/graphql/language/parser.rb

@@ -313,7 +313,7 @@ def definition
               advance_token
               directive_locations << DirectiveLocation.new(pos: pos, name: parse_name, filename: @filename, source: self)
             end
-            DirectiveDefinition.new(pos: loc, definition_pos: defn_loc, description: desc, name: name, arguments: arguments_definition, locations: directive_locations, repeatable: repeatable, filename: @filename, source: self)
+            DirectiveDefinition.new(pos: loc, definition_pos: defn_loc, description: desc, comment: comment, name: name, arguments: arguments_definition, locations: directive_locations, repeatable: repeatable, filename: @filename, source: self)
           when :TYPE
             advance_token
             name = parse_name

lib/graphql/language/printer.rb

@@ -398,6 +398,7 @@ def print_input_object_type_definition(input_object_type, extension: false)
 
       def print_directive_definition(directive)
         print_description(directive)
+        print_comment(directive)
         print_string("directive @")
         print_string(directive.name)
 

spec/graphql/language/parser_spec.rb

@@ -196,7 +196,7 @@
   end
 
   describe "string comment" do
-    it "is parsed for fields, unions, interfaces, enums, enum values, inputs and arguments" do
+    it "is parsed for fields, unions, interfaces, enums, enum values, inputs, directives and arguments" do
       document = subject.parse <<-GRAPHQL
       # type comment
       type Thing {
@@ -229,6 +229,9 @@
         # Custom input name comment
         name: String!
       }
+
+      # Directive comment
+      directive @skip(if: Boolean!) on FIELD
       GRAPHQL
 
       thing_defn = document.definitions[0]
@@ -265,6 +268,9 @@
       input_field_defn = custom_input_defn.fields[0]
       assert_equal "name", input_field_defn.name
       assert_equal "Custom input name comment", input_field_defn.comment
+
+      custom_directive_defn = document.definitions[6]
+      assert_equal "Directive comment", custom_directive_defn.comment
     end
   end
 

spec/graphql/language/printer_spec.rb

@@ -202,6 +202,7 @@
           """
           Directive description
           """
+          # Directive comment
           directive @skip(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 
           scalar AnnotatedScalar @onScalar

spec/graphql/schema/directive_spec.rb

@@ -3,12 +3,17 @@
 
 describe GraphQL::Schema::Directive do
   class MultiWord < GraphQL::Schema::Directive
+    comment "MultiWord comment"
   end
 
   it "uses a downcased class name" do
     assert_equal "multiWord", MultiWord.graphql_name
   end
 
+  it "has a comment" do
+    assert_equal "MultiWord comment", MultiWord.comment
+  end
+
   module DirectiveTest
     class Secret < GraphQL::Schema::Directive
       argument :top_secret, Boolean
@@ -248,19 +253,26 @@ class Schema < GraphQL::Schema
     end
 
     it "runs things twice when they're in with-directive and without-directive parts of the query" do
+      # TODO: Improve parser to support original inline comment positions
       query_str = <<-GRAPHQL
       {
-        t1: thing { name }      # name_resolved_count = 1
-        t2: thing { name }      # name_resolved_count = 2
+        # name_resolved_count = 1
+        t1: thing { name }
+        # name_resolved_count = 2
+        t2: thing { name }
 
         ... @countFields {
-          t1: thing { name }    # name_resolved_count = 3
-          t3: thing { name }    # name_resolved_count = 4
+          # name_resolved_count = 3
+          t1: thing { name }
+          # name_resolved_count = 4
+          t3: thing { name }
         }
 
-        t3: thing { name }      # name_resolved_count = 5
+        # name_resolved_count = 5
+        t3: thing { name }
         ... {
-          t2: thing { name @countFields } # This is merged back into `t2` above
+          # This is merged back into `t2` above
+          t2: thing { name @countFields }
         }
       }
       GRAPHQL