Support extras: [:lookahead, :ast_node] in run_graphql_field

lib/graphql/testing/helpers.rb

@@ -39,7 +39,7 @@ def initialize(type_name:, field_name:)
         end
       end
 
-      def run_graphql_field(schema, field_path, object, arguments: {}, context: {})
+      def run_graphql_field(schema, field_path, object, arguments: {}, context: {}, ast_node: nil, lookahead: nil)
         type_name, *field_names = field_path.split(".")
         dummy_query = GraphQL::Query.new(schema, "{ __typename }", context: context)
         query_context = dummy_query.context
@@ -57,6 +57,28 @@ def run_graphql_field(schema, field_path, object, arguments: {}, context: {})
               dummy_query.context.dataloader.run_isolated {
                 field_args = visible_field.coerce_arguments(graphql_result, arguments, query_context)
                 field_args = schema.sync_lazy(field_args)
+                if visible_field.extras.any?
+                  extra_args = {}
+                  visible_field.extras.each do |extra|
+                    extra_args[extra] = case extra
+                    when :ast_node
+                      ast_node ||= GraphQL::Language::Nodes::Field.new(name: visible_field.graphql_name)
+                    when :lookahead
+                      lookahead ||= begin
+                        ast_node ||= GraphQL::Language::Nodes::Field.new(name: visible_field.graphql_name)
+                        Execution::Lookahead.new(
+                          query: dummy_query,
+                          ast_nodes: [ast_node],
+                          field: visible_field,
+                        )
+                      end
+                    else
+                      raise ArgumentError, "This extra isn't supported in `run_graphql_field` yet: `#{extra.inspect}`. Open an issue on GitHub to request it: https://github.com/rmosolgo/graphql-ruby/issues/new"
+                    end
+                  end
+
+                  field_args = field_args.merge_extras(extra_args)
+                end
                 graphql_result = visible_field.resolve(graphql_result, field_args.keyword_arguments, query_context)
                 graphql_result = schema.sync_lazy(graphql_result)
               }

spec/graphql/testing/helpers_spec.rb

@@ -32,15 +32,15 @@ def self.authorized?(object, context)
         context.errors.empty?
       end
 
-      field :name, String do
+      field :name, String, extras: [:ast_node] do
         argument :full_name, Boolean, required: false
         argument :prefix, String, required: false, default_value: "Mc", prepare: ->(val, ctx) { -> { val.capitalize } }
       end
 
-      def name(full_name: nil, prefix: nil)
+      def name(full_name: nil, prefix: nil, ast_node:)
         name = object[:name]
         if full_name
-          "#{name} #{prefix}#{name}"
+          "#{name} #{ast_node.alias ? "\"#{ast_node.alias}\" " : ""}#{prefix}#{name}"
         else
           name
         end
@@ -65,7 +65,7 @@ def after_resolve(value:, **rest)
         end
       end
 
-      field :upcased_name, String, extensions: [Upcase], resolver_method: :name
+      field :upcased_name, String, extensions: [Upcase], hash_key: :name
 
       field :ssn, String do
         def authorized?(obj, args, ctx)
@@ -76,6 +76,12 @@ def authorized?(obj, args, ctx)
 
     class Query < GraphQL::Schema::Object
       field :students, [Student]
+
+      field :lookahead_selections, String, extras: [:lookahead]
+
+      def lookahead_selections(lookahead:)
+        lookahead.selections.to_s
+      end
     end
 
     query(Query)
@@ -133,6 +139,16 @@ def self.unauthorized_field(err)
         assert_equal "BILL", run_graphql_field(AssertionsSchema, "Student.upcasedName", { name: "Bill" })
       end
 
+      it "works with extras: [:ast_node]" do
+        assert_equal "Billy \"theKid\" McBilly", run_graphql_field(AssertionsSchema, "Student.name", { name: "Billy" }, arguments: { full_name: true }, ast_node: GraphQL::Language::Nodes::Field.new(name: "name", field_alias: "theKid"))
+      end
+
+      it "works with extras: [:lookahead]" do
+        assert_equal "[]", run_graphql_field(AssertionsSchema, "Query.lookaheadSelections", :something)
+        dummy_lookahead = OpenStruct.new(selections: ["one", "two"])
+        assert_equal "[\"one\", \"two\"]", run_graphql_field(AssertionsSchema, "Query.lookaheadSelections", :something, lookahead: dummy_lookahead)
+      end
+
       it "prepares arguments" do
         assert_equal "Blah De Blah", run_graphql_field(AssertionsSchema, "Student.name", { name: "Blah" }, arguments: { full_name: true, prefix: "de " })
       end