compile w/ generics

Author: Sean Sorrell

graphql.go

@@ -83,7 +83,7 @@ type Schema struct {
 	useStringDescriptions    bool
 	disableIntrospection     bool
 	subscribeResolverTimeout time.Duration
-	visitors                 map[string]types.DirectiveVisitor
+	visitors                 map[string]types.DirectiveVisitor[any,any]
 }
 
 func (s *Schema) ASTSchema() *types.Schema {
@@ -172,7 +172,7 @@ func SubscribeResolverTimeout(timeout time.Duration) SchemaOpt {
 
 // DirectiveVisitors allows to pass custom directive visitors that will be able to handle
 // your GraphQL schema directives.
-func DirectiveVisitors(visitors map[string]types.DirectiveVisitor) SchemaOpt {
+func DirectiveVisitors(visitors map[string]types.DirectiveVisitor[any,any]) SchemaOpt {
 	return func(s *Schema) {
 		s.visitors = visitors
 	}

graphql_test.go

@@ -57,20 +57,20 @@ type customDirectiveVisitor struct {
 	beforeWasCalled bool
 }
 
-func (v *customDirectiveVisitor) Before(ctx context.Context, directive *types.Directive, input interface{}) error {
+func (v *customDirectiveVisitor) Before(ctx context.Context, directive *types.Directive, input string) error {
 	v.beforeWasCalled = true
 	return nil
 }
 
-func (v *customDirectiveVisitor) After(ctx context.Context, directive *types.Directive, output interface{}) (interface{}, error) {
+func (v *customDirectiveVisitor) After(ctx context.Context, directive *types.Directive, output string) (string, error) {
 	if v.beforeWasCalled == false {
-		return nil, errors.New("Before directive visitor method wasn't called.")
+		return "", errors.New("Before directive visitor method wasn't called.")
 	}
 
 	if value, ok := directive.Arguments.Get("customAttribute"); ok {
-		return fmt.Sprintf("Directive '%s' (with arg '%s') modified result: %s", directive.Name.Name, value.String(), output.(string)), nil
+		return fmt.Sprintf("Directive '%s' (with arg '%s') modified result: %s", directive.Name.Name, value.String(), output), nil
 	}
-	return fmt.Sprintf("Directive '%s' modified result: %s", directive.Name.Name, output.(string)), nil
+	return fmt.Sprintf("Directive '%s' modified result: %s", directive.Name.Name, output), nil
 }
 
 type theNumberResolver struct {
@@ -286,7 +286,7 @@ func TestCustomDirective(t *testing.T) {
 					hello_html: String! @customDirective
 				}
 			`, &helloSnakeResolver1{},
-				graphql.DirectiveVisitors(map[string]types.DirectiveVisitor{
+				graphql.DirectiveVisitors(map[string]types.DirectiveVisitor[any,any]{
 					"customDirective": &customDirectiveVisitor{},
 				})),
 			Query: `
@@ -314,7 +314,7 @@ func TestCustomDirective(t *testing.T) {
 					say_hello(full_name: String!): String! @customDirective(customAttribute: hi)
 				}
 			`, &helloSnakeResolver1{},
-				graphql.DirectiveVisitors(map[string]types.DirectiveVisitor{
+				graphql.DirectiveVisitors(map[string]types.DirectiveVisitor[any,any]{
 					"customDirective": &customDirectiveVisitor{},
 				})),
 			Query: `
@@ -335,7 +335,7 @@ func TestCustomDirectiveStructFieldResolver(t *testing.T) {
 	t.Parallel()
 
 	schemaOpt := []graphql.SchemaOpt{
-		graphql.DirectiveVisitors(map[string]types.DirectiveVisitor{
+		graphql.DirectiveVisitors(map[string]types.DirectiveVisitor[any,any]{
 			"customDirective": &customDirectiveVisitor{},
 		}),
 		graphql.UseFieldResolvers(),

internal/exec/exec.go

@@ -25,7 +25,7 @@ type Request struct {
 	Logger                   log.Logger
 	PanicHandler             errors.PanicHandler
 	SubscribeResolverTimeout time.Duration
-	Visitors                 map[string]types.DirectiveVisitor
+	Visitors                 map[string]types.DirectiveVisitor[any,any]
 }
 
 func (r *Request) handlePanic(ctx context.Context) {

types/directive.go

@@ -28,9 +28,9 @@ type DirectiveDefinition struct {
 
 type DirectiveList []*Directive
 
-type DirectiveVisitor interface {
-	Before(ctx context.Context, directive *Directive, input interface{}) error
-	After(ctx context.Context, directive *Directive, output interface{}) (interface{}, error)
+type DirectiveVisitor[In any, Out any] interface {
+	Before(ctx context.Context, directive *Directive, input In) error
+	After(ctx context.Context, directive *Directive, output Out) (Out, error)
 }
 
 // Returns the Directive in the DirectiveList by name or nil if not found.