Allow directives on schema (graph-gophers#585)

Author: pavelnikolov

ast/schema.go

@@ -1,5 +1,7 @@
 package ast
 
+import "github.com/graph-gophers/graphql-go/errors"
+
 // Schema represents a GraphQL service's collective type system capabilities.
 // A schema is defined in terms of the types and directives it supports as well as the root
 // operation types for each kind of operation: `query`, `mutation`, and `subscription`.
@@ -8,12 +10,8 @@ package ast
 //
 // http://spec.graphql.org/draft/#sec-Schema
 type Schema struct {
-	// RootOperationTypes determines the place in the type system where `query`, `mutation`, and
-	// `subscription` operations begin.
-	//
-	// http://spec.graphql.org/draft/#sec-Root-Operation-Types
-	//
-	RootOperationTypes map[string]NamedType
+	// SchemaDefinition corresponds to the `schema` sdl keyword.
+	SchemaDefinition
 
 	// Types are the fundamental unit of any GraphQL schema.
 	// There are six kinds of named type definitions in GraphQL, and two wrapping types.
@@ -28,14 +26,71 @@ type Schema struct {
 	// http://spec.graphql.org/#sec-Type-System.Directives
 	Directives map[string]*DirectiveDefinition
 
-	EntryPointNames map[string]string
-	Objects         []*ObjectTypeDefinition
-	Unions          []*Union
-	Enums           []*EnumTypeDefinition
-	Extensions      []*Extension
-	SchemaString    string
+	Objects      []*ObjectTypeDefinition
+	Unions       []*Union
+	Enums        []*EnumTypeDefinition
+	Extensions   []*Extension
+	SchemaString string
 }
 
 func (s *Schema) Resolve(name string) Type {
 	return s.Types[name]
 }
+
+// SchemaDefinition is an optional schema block.
+// If the schema definition is present it might contain a description and directives. It also contains a map of root operations. For example:
+//
+//	schema {
+//	  query: Query
+//	  mutation: Mutation
+//	  subscription: Subscription
+//	}
+//
+//	type Query {
+//	  # query fields go here
+//	}
+//
+//	type Mutation {
+//	  # mutation fields go here
+//	}
+//
+//	type Subscription {
+//	  # subscription fields go here
+//	}
+//
+// If the root operations have default names (i.e. Query, Mutation and Subscription), then the schema definition can be omitted. For example, this is equivalent to the above schema:
+//
+//	type Query {
+//	  # query fields go here
+//	}
+//
+//	type Mutation {
+//	  # mutation fields go here
+//	}
+//
+//	type Subscription {
+//	  # subscription fields go here
+//	}
+//
+// https://spec.graphql.org/October2021/#sec-Schema
+type SchemaDefinition struct {
+	// Present is true if the schema definition is not omitted, false otherwise. For example, in the following schema
+	//
+	//	type Query {
+	//		hello: String!
+	//	}
+	//
+	// the schema keyword is omitted since the default name for Query is used. In that case Present would be false.
+	Present bool
+
+	// RootOperationTypes determines the place in the type system where `query`, `mutation`, and
+	// `subscription` operations begin.
+	//
+	// http://spec.graphql.org/draft/#sec-Root-Operation-Types
+	RootOperationTypes map[string]NamedType
+
+	EntryPointNames map[string]string
+	Desc            string
+	Directives      DirectiveList
+	Loc             errors.Location
+}

examples_test.go

@@ -292,6 +292,7 @@ func (s Season) String() string {
 	panic("unreachable")
 }
 `
+
 	funcs := template.FuncMap{
 		"toVar": func(s string) string {
 			if len(s) == 0 {
@@ -300,6 +301,7 @@ func (s Season) String() string {
 			return strings.ToUpper(s[:1]) + strings.ToLower(s[1:])
 		},
 	}
+
 	tpl, err := template.New("enum").Funcs(funcs).Parse(gocode)
 	if err != nil {
 		panic(err)

internal/schema/schema.go

@@ -12,9 +12,11 @@ import (
 // New initializes an instance of Schema.
 func New() *ast.Schema {
 	s := &ast.Schema{
-		EntryPointNames: make(map[string]string),
-		Types:           make(map[string]ast.NamedType),
-		Directives:      make(map[string]*ast.DirectiveDefinition),
+		SchemaDefinition: ast.SchemaDefinition{
+			EntryPointNames: make(map[string]string),
+		},
+		Types:      make(map[string]ast.NamedType),
+		Directives: make(map[string]*ast.DirectiveDefinition),
 	}
 	m := newMeta()
 	for n, t := range m.Types {
@@ -362,6 +364,10 @@ func parseSchema(s *ast.Schema, l *common.Lexer) {
 		switch x := l.ConsumeIdent(); x {
 
 		case "schema":
+			s.SchemaDefinition.Present = true
+			s.SchemaDefinition.Loc = l.Location()
+			s.SchemaDefinition.Desc = desc
+			s.SchemaDefinition.Directives = common.ParseDirectives(l)
 			l.ConsumeToken('{')
 			for l.Peek() != '}' {
 
@@ -565,6 +571,8 @@ func parseExtension(s *ast.Schema, l *common.Lexer) {
 	switch x := l.ConsumeIdent(); x {
 	case "schema":
 		l.ConsumeToken('{')
+		s.SchemaDefinition.Present = true
+		s.SchemaDefinition.Directives = append(s.SchemaDefinition.Directives, common.ParseDirectives(l)...)
 		for l.Peek() != '}' {
 			name := l.ConsumeIdent()
 			l.ConsumeToken(':')