feat: add initial defer support

execution/engine/config_factory_proxy_test.go

@@ -132,6 +132,7 @@ func TestProxyEngineConfigFactory_EngineConfiguration(t *testing.T) {
 		expectedConfig.SetFieldConfigurations(expectedFieldConfigs)
 		sortFieldConfigurations(config.FieldConfigurations())
 
+		assert.Equal(t, graphqlGeneratorFullSchema, string(config.Schema().RawSchema()))
 		assert.Equal(t, expectedConfig, config)
 	})
 

execution/engine/engine_config_test.go

@@ -358,19 +358,21 @@ type Language {
     __typename: String!
 }
 
-"The 'Int' scalar type represents non-fractional signed whole numeric values. Int can represent values between -(2^31) and 2^31 - 1."
+"The ` + "`Int`" + ` scalar type represents non-fractional signed whole numeric values. Int can represent values between -(2^31) and 2^31 - 1."
 scalar Int
 
-"The 'Float' scalar type represents signed double-precision fractional values as specified by [IEEE 754](http://en.wikipedia.org/wiki/IEEE_floating_point)."
+"The ` + "`Float`" + ` scalar type represents signed double-precision fractional values as specified by [IEEE 754](http://en.wikipedia.org/wiki/IEEE_floating_point)."
 scalar Float
 
-"The 'String' scalar type represents textual data, represented as UTF-8 character sequences. The String type is most often used by GraphQL to represent free-form human-readable text."
+"The ` + "`String`" + ` scalar type represents textual data, represented as UTF-8 character sequences. The String type is most often used by GraphQL to represent free-form human-readable text."
 scalar String
 
-"The 'Boolean' scalar type represents 'true' or 'false' ."
+"The ` + "`Boolean` scalar type represents `true` or `false`." + `"
 scalar Boolean
 
-"The 'ID' scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as '4') or integer (such as 4) input value will be accepted as an ID."
+"""
+The ` + "`ID`" + ` scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as "4") or integer (such as 4) input value will be accepted as an ID.
+"""
 scalar ID
 
 "Directs the executor to include this field or fragment only when the argument is true."
@@ -395,7 +397,9 @@ directive @deprecated(
     reason: String = "No longer supported"
 ) on FIELD_DEFINITION | ARGUMENT_DEFINITION | ENUM_VALUE | INPUT_FIELD_DEFINITION
 
+"Exposes a URL that specifies the behavior of this scalar"
 directive @specifiedBy(
+    "The URL that specifies the behavior of this scalar."
     url: String!
 ) on SCALAR
 
@@ -406,6 +410,14 @@ All fields defined within a @oneOf input must be nullable in the schema.
 """
 directive @oneOf on INPUT_OBJECT
 
+"Directs the executor to defer this fragment when the if argument is true or undefined."
+directive @defer(
+    "A unique identifier for the results."
+    label: String
+    "Controls whether the fragment will be deferred, usually via a variable."
+    if: Boolean! = true
+) on FRAGMENT_SPREAD | INLINE_FRAGMENT
+
 """
 A Directive provides a way to describe alternate runtime execution and type validation behavior in a GraphQL document.
 In some cases, you need to provide options to alter GraphQL's execution behavior
@@ -571,4 +583,11 @@ enum __TypeKind {
     LIST
     "Indicates this type is a non-null. 'ofType' is a valid field."
     NON_NULL
-}`
+}
+
+directive @__defer_internal(
+    id: String!
+    parentDeferId: String
+    "A unique identifier for the results."
+    label: String
+) repeatable on FIELD`

execution/engine/execution_engine.go

@@ -153,6 +153,7 @@ func (e *ExecutionEngine) Execute(ctx context.Context, operation *graphql.Reques
 			astnormalization.WithRemoveFragmentDefinitions(),
 			astnormalization.WithRemoveUnusedVariables(),
 			astnormalization.WithInlineFragmentSpreads(),
+			astnormalization.WithInlineDefer(),
 		)
 		if err != nil {
 			return err
@@ -243,6 +244,9 @@ func (e *ExecutionEngine) Execute(ctx context.Context, operation *graphql.Reques
 			operation.ComputeActualCost(costCalculator, e.config.plannerConfig, execContext.resolveContext.ActualListSizes)
 		}
 		return nil
+	case *plan.DeferResponsePlan:
+		_, err := e.resolver.ResolveGraphQLDeferResponse(execContext.resolveContext, p.Response, writer)
+		return err
 	case *plan.SubscriptionResponsePlan:
 		return e.resolver.ResolveGraphQLSubscription(execContext.resolveContext, p.Response, writer)
 	default: