add graphql

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

graphql/generator.go

@@ -0,0 +1,761 @@
+package generator
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/jhump/protoreflect/desc"
+	"github.com/vektah/gqlparser/v2/ast"
+	"google.golang.org/protobuf/compiler/protogen"
+	descriptor "google.golang.org/protobuf/types/descriptorpb"
+
+	gqlpb "go.unistack.org/micro-proto/v3/graphql"
+)
+
+const (
+	fieldPrefix        = "Field"
+	inputSuffix        = "Input"
+	typeSep            = "_"
+	packageSep         = "."
+	anyTypeDescription = "Any is any json type"
+	scalarBytes        = "Bytes"
+	goFieldDirective   = "goField"
+
+	DefaultExtension = "graphql"
+)
+
+func NewSchemas(descs []*desc.FileDescriptor, mergeSchemas, genServiceDesc bool, plugin *protogen.Plugin) (schemas SchemaDescriptorList, err error) {
+	var files []*descriptor.FileDescriptorProto
+	for _, d := range descs {
+		files = append(files, d.AsFileDescriptorProto())
+	}
+	var goref GoRef
+	if plugin != nil {
+		goref, err = NewGoRef(plugin)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if mergeSchemas {
+		schema := NewSchemaDescriptor(genServiceDesc, goref)
+		for _, file := range descs {
+			err := generateFile(file, schema)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		return []*SchemaDescriptor{schema}, nil
+	}
+
+	for _, file := range descs {
+		schema := NewSchemaDescriptor(genServiceDesc, goref)
+		err := generateFile(file, schema)
+		if err != nil {
+			return nil, err
+		}
+
+		schemas = append(schemas, schema)
+	}
+
+	return
+}
+
+func generateFile(file *desc.FileDescriptor, schema *SchemaDescriptor) error {
+	schema.FileDescriptors = append(schema.FileDescriptors, file)
+
+	for _, svc := range file.GetServices() {
+		svcOpts := GraphqlServiceOptions(svc.AsServiceDescriptorProto().GetOptions())
+		if svcOpts != nil && svcOpts.Ignore != nil && *svcOpts.Ignore {
+			continue
+		}
+		for _, rpc := range svc.GetMethods() {
+			rpcOpts := GraphqlMethodOptions(rpc.AsMethodDescriptorProto().GetOptions())
+			if rpcOpts != nil && rpcOpts.Ignore != nil && *rpcOpts.Ignore {
+				continue
+			}
+			in, err := schema.CreateObjects(rpc.GetInputType(), true)
+			if err != nil {
+				return err
+			}
+
+			out, err := schema.CreateObjects(rpc.GetOutputType(), false)
+			if err != nil {
+				return err
+			}
+
+			if rpc.IsServerStreaming() && rpc.IsClientStreaming() {
+				schema.GetMutation().addMethod(svc, rpc, in, out)
+			}
+
+			if rpc.IsServerStreaming() {
+				schema.GetSubscription().addMethod(svc, rpc, in, out)
+			} else {
+				switch GetRequestType(rpcOpts, svcOpts) {
+				case gqlpb.Type_QUERY:
+					schema.GetQuery().addMethod(svc, rpc, in, out)
+				default:
+					schema.GetMutation().addMethod(svc, rpc, in, out)
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+type SchemaDescriptorList []*SchemaDescriptor
+
+func (s SchemaDescriptorList) AsGraphql() (astSchema []*ast.Schema) {
+	for _, ss := range s {
+		astSchema = append(astSchema, ss.AsGraphql())
+	}
+	return
+}
+
+func (s SchemaDescriptorList) GetForDescriptor(file *protogen.File) *SchemaDescriptor {
+	for _, schema := range s {
+		for _, d := range schema.FileDescriptors {
+			if d.AsFileDescriptorProto() == file.Proto {
+				return schema
+			}
+		}
+	}
+	return nil
+}
+
+func NewSchemaDescriptor(genServiceDesc bool, goref GoRef) *SchemaDescriptor {
+	sd := &SchemaDescriptor{
+		Directives:                 map[string]*ast.DirectiveDefinition{},
+		reservedNames:              map[string]desc.Descriptor{},
+		createdObjects:             map[createdObjectKey]*ObjectDescriptor{},
+		generateServiceDescriptors: genServiceDesc,
+		goRef:                      goref,
+	}
+	for _, name := range graphqlReservedNames {
+		sd.reservedNames[name] = nil
+	}
+	return sd
+}
+
+type SchemaDescriptor struct {
+	Directives      map[string]*ast.DirectiveDefinition
+	FileDescriptors []*desc.FileDescriptor
+
+	files []*desc.FileDescriptor
+
+	query        *RootDefinition
+	mutation     *RootDefinition
+	subscription *RootDefinition
+
+	objects []*ObjectDescriptor
+
+	reservedNames  map[string]desc.Descriptor
+	createdObjects map[createdObjectKey]*ObjectDescriptor
+
+	generateServiceDescriptors bool
+
+	goRef GoRef
+}
+
+type createdObjectKey struct {
+	desc  desc.Descriptor
+	input bool
+}
+
+func (s *SchemaDescriptor) AsGraphql() *ast.Schema {
+	queryDef := *s.GetQuery().Definition
+	mutationDef := *s.GetMutation().Definition
+	subscriptionsDef := *s.GetSubscription().Definition
+	schema := &ast.Schema{Types: map[string]*ast.Definition{}, Directives: s.Directives}
+	schema.Query = &queryDef
+	schema.Types["Query"] = &queryDef
+	if s.query.methods == nil {
+		schema.Query.Fields = append(schema.Query.Fields, &ast.FieldDefinition{
+			Name: "dummy",
+			Type: ast.NamedType("Boolean", &ast.Position{}),
+		})
+	}
+	if s.mutation.methods != nil {
+		schema.Mutation = &mutationDef
+		schema.Types["Mutation"] = &mutationDef
+	}
+	if s.subscription.methods != nil {
+		schema.Subscription = &subscriptionsDef
+		schema.Types["Subscription"] = &subscriptionsDef
+	}
+
+	for _, o := range s.objects {
+		def := o.AsGraphql()
+		schema.Types[def.Name] = def
+	}
+	return schema
+}
+
+func (s *SchemaDescriptor) Objects() []*ObjectDescriptor {
+	return s.objects
+}
+
+func (s *SchemaDescriptor) GetMutation() *RootDefinition {
+	if s.mutation == nil {
+		s.mutation = NewRootDefinition(Mutation, s)
+	}
+	return s.mutation
+}
+
+func (s *SchemaDescriptor) GetSubscription() *RootDefinition {
+	if s.subscription == nil {
+		s.subscription = NewRootDefinition(Subscription, s)
+	}
+	return s.subscription
+}
+
+func (s *SchemaDescriptor) GetQuery() *RootDefinition {
+	if s.query == nil {
+		s.query = NewRootDefinition(Query, s)
+	}
+
+	return s.query
+}
+
+// make name be unique
+// just create a map and register every name
+func (s *SchemaDescriptor) uniqueName(d desc.Descriptor, input bool) (name string) {
+	var collisionPrefix string
+	var suffix string
+	if _, ok := d.(*desc.MessageDescriptor); input && ok {
+		suffix = inputSuffix
+	}
+	name = strings.Title(CamelCaseSlice(strings.Split(strings.TrimPrefix(d.GetFullyQualifiedName(), d.GetFile().GetPackage()+packageSep), packageSep)) + suffix)
+
+	if _, ok := d.(*desc.FieldDescriptor); ok {
+		collisionPrefix = fieldPrefix
+		name = CamelCaseSlice(strings.Split(strings.Trim(d.GetParent().GetName()+packageSep+strings.Title(d.GetName()), packageSep), packageSep))
+	} else {
+		collisionPrefix = CamelCaseSlice(strings.Split(d.GetFile().GetPackage(), packageSep))
+	}
+
+	originalName := name
+	for uniqueSuffix := 0; ; uniqueSuffix++ {
+		d2, ok := s.reservedNames[name]
+		if !ok {
+			break
+		}
+		if d2 == d {
+			return name
+		}
+		if uniqueSuffix == 0 {
+			name = collisionPrefix + typeSep + originalName
+			continue
+		}
+		name = collisionPrefix + typeSep + originalName + strconv.Itoa(uniqueSuffix)
+	}
+
+	s.reservedNames[name] = d
+	return
+}
+
+func (s *SchemaDescriptor) CreateObjects(d desc.Descriptor, input bool) (obj *ObjectDescriptor, err error) {
+	// the case if trying to resolve a primitive as a object. In this case we just return nil
+	if d == nil {
+		return
+	}
+	if obj, ok := s.createdObjects[createdObjectKey{d, input}]; ok {
+		return obj, nil
+	}
+
+	obj = &ObjectDescriptor{
+		Definition: &ast.Definition{
+			Description: getDescription(d),
+			Name:        s.uniqueName(d, input),
+			Position:    &ast.Position{},
+		},
+		Descriptor: d,
+	}
+
+	s.createdObjects[createdObjectKey{d, input}] = obj
+
+	switch dd := d.(type) {
+	case *desc.MessageDescriptor:
+		if IsEmpty(dd) {
+			return obj, nil
+		}
+		if IsAny(dd) {
+			// TODO find a better way to handle any types
+			delete(s.createdObjects, createdObjectKey{d, input})
+			any := s.createScalar(s.uniqueName(dd, false), anyTypeDescription)
+			return any, nil
+		}
+
+		kind := ast.Object
+		if input {
+			kind = ast.InputObject
+		}
+		fields := FieldDescriptorList{}
+		outputOneofRegistrar := map[*desc.OneOfDescriptor]struct{}{}
+
+		for _, df := range dd.GetFields() {
+			fieldOpts := GraphqlFieldOptions(df.AsFieldDescriptorProto().GetOptions())
+			if fieldOpts != nil && fieldOpts.Ignore != nil && *fieldOpts.Ignore {
+				continue
+			}
+			var fieldDirective []*ast.Directive
+			if df.GetType() == descriptor.FieldDescriptorProto_TYPE_MESSAGE && IsEmpty(df.GetMessageType()) {
+				continue
+			}
+
+			// Internally `optional` fields are represented as a oneof, and as such should be skipped.
+			if oneof := df.GetOneOf(); oneof != nil && !df.AsFieldDescriptorProto().GetProto3Optional() {
+				opts := GraphqlOneofOptions(oneof.AsOneofDescriptorProto().GetOptions())
+				if opts.GetIgnore() {
+					continue
+				}
+				if !input {
+					if _, ok := outputOneofRegistrar[oneof]; ok {
+						continue
+					}
+					outputOneofRegistrar[oneof] = struct{}{}
+					field, err := s.createUnion(oneof)
+					if err != nil {
+						return nil, err
+					}
+					fields = append(fields, field)
+					continue
+				}
+
+				// create oneofs as directives for input objects
+				directive := &ast.DirectiveDefinition{
+					Description: getDescription(oneof),
+					Name:        s.uniqueName(oneof, input),
+					Locations:   []ast.DirectiveLocation{ast.LocationInputFieldDefinition},
+					Position:    &ast.Position{Src: &ast.Source{}},
+				}
+				s.Directives[directive.Name] = directive
+				fieldDirective = append(fieldDirective, &ast.Directive{
+					Name:     directive.Name,
+					Position: &ast.Position{Src: &ast.Source{}},
+					// ParentDefinition: obj.Definition, TODO
+					Definition: directive,
+					Location:   ast.LocationInputFieldDefinition,
+				})
+			}
+
+			fieldObj, err := s.CreateObjects(resolveFieldType(df), input)
+			if err != nil {
+				return nil, err
+			}
+			if fieldObj == nil && df.GetMessageType() != nil {
+				continue
+			}
+			f, err := s.createField(df, fieldObj)
+			if err != nil {
+				return nil, err
+			}
+			f.Directives = append(f.Directives, fieldDirective...)
+			fields = append(fields, f)
+		}
+
+		obj.Definition.Fields = fields.AsGraphql()
+		obj.Definition.Kind = kind
+		obj.fields = fields
+	case *desc.EnumDescriptor:
+		obj.Definition.Kind = ast.Enum
+		obj.Definition.EnumValues = enumValues(dd.GetValues())
+	default:
+		panic(fmt.Sprintf("received unexpected value %v of type %T", dd, dd))
+	}
+
+	s.objects = append(s.objects, obj)
+	return obj, nil
+}
+
+func resolveFieldType(field *desc.FieldDescriptor) desc.Descriptor {
+	msgType := field.GetMessageType()
+	enumType := field.GetEnumType()
+	if msgType != nil {
+		return msgType
+	}
+	if enumType != nil {
+		return enumType
+	}
+	return nil
+}
+
+func enumValues(evals []*desc.EnumValueDescriptor) (vlist ast.EnumValueList) {
+	for _, eval := range evals {
+		vlist = append(vlist, &ast.EnumValueDefinition{
+			Description: getDescription(eval),
+			Name:        eval.GetName(),
+			Position:    &ast.Position{},
+		})
+	}
+
+	return vlist
+}
+
+type FieldDescriptorList []*FieldDescriptor
+
+func (fl FieldDescriptorList) AsGraphql() (dl []*ast.FieldDefinition) {
+	for _, f := range fl {
+		dl = append(dl, f.FieldDefinition)
+	}
+	return dl
+}
+
+type FieldDescriptor struct {
+	*ast.FieldDefinition
+	*desc.FieldDescriptor
+
+	typ *ObjectDescriptor
+}
+
+func (f *FieldDescriptor) GetType() *ObjectDescriptor {
+	return f.typ
+}
+
+type MethodDescriptor struct {
+	*desc.ServiceDescriptor
+	*desc.MethodDescriptor
+
+	*ast.FieldDefinition
+
+	input  *ObjectDescriptor
+	output *ObjectDescriptor
+}
+
+func (m *MethodDescriptor) AsGraphql() *ast.FieldDefinition {
+	return m.FieldDefinition
+}
+
+func (m *MethodDescriptor) GetInput() *ObjectDescriptor {
+	return m.input
+}
+
+func (m *MethodDescriptor) GetOutput() *ObjectDescriptor {
+	return m.output
+}
+
+type RootDefinition struct {
+	*ast.Definition
+
+	Parent *SchemaDescriptor
+
+	methods       []*MethodDescriptor
+	reservedNames map[string]ServiceAndMethod
+}
+
+type ServiceAndMethod struct {
+	svc *descriptor.ServiceDescriptorProto
+	rpc *descriptor.MethodDescriptorProto
+}
+
+func (r *RootDefinition) UniqueName(svc *descriptor.ServiceDescriptorProto, rpc *descriptor.MethodDescriptorProto) (name string) {
+	rpcOpts := GraphqlMethodOptions(rpc.GetOptions())
+	svcOpts := GraphqlServiceOptions(svc.GetOptions())
+	if rpcOpts != nil && rpcOpts.Name != nil {
+		name = *rpcOpts.Name
+	} else if svcOpts != nil && svcOpts.Name != nil {
+		if *svcOpts.Name == "" {
+			name = ToLowerFirst(rpc.GetName())
+		} else {
+			name = *svcOpts.Name + strings.Title(rpc.GetName())
+		}
+	} else {
+		name = ToLowerFirst(svc.GetName()) + strings.Title(rpc.GetName())
+	}
+
+	originalName := name
+	for uniqueSuffix := 0; ; uniqueSuffix++ {
+		snm, ok := r.reservedNames[name]
+		if !ok {
+			break
+		}
+		if svc == snm.svc && snm.rpc == rpc {
+			return name
+		}
+		name = originalName + strconv.Itoa(uniqueSuffix)
+	}
+
+	r.reservedNames[name] = ServiceAndMethod{svc, rpc}
+	return
+}
+
+func (r *RootDefinition) Methods() []*MethodDescriptor {
+	return r.methods
+}
+
+func (r *RootDefinition) addMethod(svc *desc.ServiceDescriptor, rpc *desc.MethodDescriptor, in, out *ObjectDescriptor) {
+	var args ast.ArgumentDefinitionList
+
+	if in != nil && (in.Descriptor != nil && !IsEmpty(in.Descriptor.(*desc.MessageDescriptor)) || in.Definition.Kind == ast.Scalar) {
+		args = append(args, &ast.ArgumentDefinition{
+			Name:     "in",
+			Type:     ast.NamedType(in.Name, &ast.Position{}),
+			Position: &ast.Position{},
+		})
+	}
+	objType := ast.NamedType("Boolean", &ast.Position{})
+	if out != nil && (out.Descriptor != nil && !IsEmpty(out.Descriptor.(*desc.MessageDescriptor)) || in.Definition.Kind == ast.Scalar) {
+		objType = ast.NamedType(out.Name, &ast.Position{})
+	}
+
+	svcDir := &ast.DirectiveDefinition{
+		Description: getDescription(svc),
+		Name:        svc.GetName(),
+		Locations:   []ast.DirectiveLocation{ast.LocationFieldDefinition},
+		Position:    &ast.Position{Src: &ast.Source{}},
+	}
+	r.Parent.Directives[svcDir.Name] = svcDir
+
+	m := &MethodDescriptor{
+		ServiceDescriptor: svc,
+		MethodDescriptor:  rpc,
+		FieldDefinition: &ast.FieldDefinition{
+			Description: getDescription(rpc),
+			Name:        r.UniqueName(svc.AsServiceDescriptorProto(), rpc.AsMethodDescriptorProto()),
+			Arguments:   args,
+			Type:        objType,
+			Position:    &ast.Position{},
+		},
+		input:  in,
+		output: out,
+	}
+	if r.Parent.generateServiceDescriptors {
+		m.Directives = []*ast.Directive{{
+			Name:       svcDir.Name,
+			Position:   &ast.Position{},
+			Definition: svcDir,
+			Location:   svcDir.Locations[0],
+		}}
+	}
+
+	r.methods = append(r.methods, m)
+	// TODO maybe not do it here?
+	r.Definition.Fields = append(r.Definition.Fields, m.FieldDefinition)
+}
+
+type rootName string
+
+const (
+	Mutation     rootName = "Mutation"
+	Query        rootName = "Query"
+	Subscription rootName = "Subscription"
+)
+
+func NewRootDefinition(name rootName, parent *SchemaDescriptor) *RootDefinition {
+	return &RootDefinition{Definition: &ast.Definition{
+		Kind:     ast.Object,
+		Name:     string(name),
+		Position: &ast.Position{},
+	}, Parent: parent, reservedNames: map[string]ServiceAndMethod{}}
+}
+
+func getDescription(descs ...desc.Descriptor) string {
+	var description []string
+	for _, d := range descs {
+		info := d.GetSourceInfo()
+		if info == nil {
+			continue
+		}
+		if info.LeadingComments != nil {
+			description = append(description, *info.LeadingComments)
+		}
+		if info.TrailingComments != nil {
+			description = append(description, *info.TrailingComments)
+		}
+	}
+
+	return strings.Join(description, "\n")
+}
+
+func (s *SchemaDescriptor) createField(field *desc.FieldDescriptor, obj *ObjectDescriptor) (_ *FieldDescriptor, err error) {
+	fieldAst := &ast.FieldDefinition{
+		Description: getDescription(field),
+		Name:        ToLowerFirst(CamelCase(field.GetName())),
+		Type:        &ast.Type{Position: &ast.Position{}},
+		Position:    &ast.Position{},
+	}
+	fieldOpts := GraphqlFieldOptions(field.AsFieldDescriptorProto().GetOptions())
+	if fieldOpts != nil && fieldOpts.Name != nil {
+		fieldAst.Name = *fieldOpts.Name
+		directive := &ast.DirectiveDefinition{
+			Name: goFieldDirective,
+			Arguments: []*ast.ArgumentDefinition{{
+				Name:     "forceResolver",
+				Type:     ast.NamedType("Boolean", &ast.Position{}),
+				Position: &ast.Position{},
+			}, {
+				Name:     "name",
+				Type:     ast.NamedType("String", &ast.Position{}),
+				Position: &ast.Position{},
+			}},
+			Locations: []ast.DirectiveLocation{ast.LocationInputFieldDefinition, ast.LocationFieldDefinition},
+			Position:  &ast.Position{Src: &ast.Source{}},
+		}
+		s.Directives[directive.Name] = directive
+		if s.goRef != nil {
+			fieldAst.Directives = []*ast.Directive{{
+				Name: directive.Name,
+				Arguments: []*ast.Argument{{
+					Name: "name",
+					Value: &ast.Value{
+						Raw:      s.goRef.FindGoField(field.GetFullyQualifiedName()).GoName,
+						Kind:     ast.StringValue,
+						Position: &ast.Position{},
+					},
+					Position: &ast.Position{},
+				}},
+				Position: &ast.Position{},
+				// ParentDefinition: nil, TODO
+				Definition: directive,
+			}}
+		}
+	}
+	switch field.GetType() {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		fieldAst.Type.NamedType = ScalarFloat
+
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		scalar := s.createScalar(scalarBytes, "")
+		fieldAst.Type.NamedType = scalar.Name
+
+	case descriptor.FieldDescriptorProto_TYPE_INT64,
+		descriptor.FieldDescriptorProto_TYPE_SINT64,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_INT32,
+		descriptor.FieldDescriptorProto_TYPE_SINT32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_UINT32,
+		descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_UINT64,
+		descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		fieldAst.Type.NamedType = ScalarInt
+
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		fieldAst.Type.NamedType = ScalarBoolean
+
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		fieldAst.Type.NamedType = ScalarString
+
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return nil, fmt.Errorf("proto2 groups are not supported please use proto3 syntax")
+
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		fieldAst.Type.NamedType = obj.Name
+
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		fieldAst.Type.NamedType = obj.Name
+
+	default:
+		panic("unknown proto field type")
+	}
+
+	if isRepeated(field) {
+		fieldAst.Type = ast.ListType(fieldAst.Type, &ast.Position{})
+		fieldAst.Type.Elem.NonNull = true
+	}
+	if isRequired(field) {
+		fieldAst.Type.NonNull = true
+	}
+
+	return &FieldDescriptor{
+		FieldDefinition: fieldAst,
+		FieldDescriptor: field,
+		typ:             obj,
+	}, nil
+}
+
+func (s *SchemaDescriptor) createScalar(name string, description string) *ObjectDescriptor {
+	obj := &ObjectDescriptor{
+		Definition: &ast.Definition{
+			Kind:        ast.Scalar,
+			Description: description,
+			Name:        name,
+			Position:    &ast.Position{},
+		},
+	}
+	s.objects = append(s.objects, obj)
+	return obj
+}
+
+func (s *SchemaDescriptor) createUnion(oneof *desc.OneOfDescriptor) (*FieldDescriptor, error) {
+	var types []string
+	var objTypes []*ObjectDescriptor
+	for _, choice := range oneof.GetChoices() {
+		obj, err := s.CreateObjects(resolveFieldType(choice), false)
+		if err != nil {
+			return nil, err
+		}
+		f, err := s.createField(choice, obj)
+		if err != nil {
+			return nil, err
+		}
+
+		obj = &ObjectDescriptor{
+			Definition: &ast.Definition{
+				Kind:        ast.Object,
+				Description: getDescription(f),
+				Name:        s.uniqueName(choice, false),
+				Fields:      ast.FieldList{f.FieldDefinition},
+				Position:    &ast.Position{},
+			},
+			Descriptor: f,
+			fields:     []*FieldDescriptor{f},
+			fieldNames: map[string]*FieldDescriptor{},
+		}
+		s.objects = append(s.objects, obj)
+		types = append(types, obj.Name)
+		objTypes = append(objTypes, obj)
+	}
+	obj := &ObjectDescriptor{
+		Definition: &ast.Definition{
+			Kind:        ast.Union,
+			Description: getDescription(oneof),
+			Name:        s.uniqueName(oneof, false),
+			Types:       types,
+			Position:    &ast.Position{},
+		},
+		Descriptor: oneof,
+		types:      objTypes,
+	}
+	s.objects = append(s.objects, obj)
+	name := ToLowerFirst(CamelCase(oneof.GetName()))
+	opts := GraphqlOneofOptions(oneof.AsOneofDescriptorProto().GetOptions())
+	if opts.GetName() != "" {
+		name = opts.GetName()
+	}
+	return &FieldDescriptor{
+		FieldDefinition: &ast.FieldDefinition{
+			Description: getDescription(oneof),
+			Name:        name,
+			Type:        ast.NamedType(obj.Name, &ast.Position{}),
+			Position:    &ast.Position{},
+		},
+		FieldDescriptor: nil,
+		typ:             obj,
+	}, nil
+}
+
+func isRepeated(field *desc.FieldDescriptor) bool {
+	return field.GetLabel() == descriptor.FieldDescriptorProto_LABEL_REPEATED
+}
+
+func isRequired(field *desc.FieldDescriptor) bool {
+	if v := GraphqlFieldOptions(field.AsFieldDescriptorProto().GetOptions()); v != nil {
+		return v.GetRequired()
+	}
+	return false
+}
+
+const (
+	ScalarInt     = "Int"
+	ScalarFloat   = "Float"
+	ScalarString  = "String"
+	ScalarBoolean = "Boolean"
+	ScalarID      = "ID"
+)
+
+var graphqlReservedNames = []string{"__Directive", "__Type", "__Field", "__EnumValue", "__InputValue", "__Schema", "Int", "Float", "String", "Boolean", "ID"}