fix to support schema printed by graphene package

issue: graphql-python/graphene#1209

commit-id:1a2b2003

pkg/astparser/parser.go

@@ -727,7 +727,6 @@ func (p *Parser) parseImplementsInterfaces() (list ast.TypeList) {
 
 	p.read() // implements
 
-	acceptIdent := true
 	acceptAnd := true
 
 	for {
@@ -736,28 +735,21 @@ func (p *Parser) parseImplementsInterfaces() (list ast.TypeList) {
 		case keyword.AND:
 			if acceptAnd {
 				acceptAnd = false
-				acceptIdent = true
 				p.read()
 			} else {
 				p.errUnexpectedToken(p.read())
 				return
 			}
 		case keyword.IDENT:
-			if acceptIdent {
-				acceptIdent = false
 				acceptAnd = true
 				name := p.read()
 				ref := p.document.AddNamedTypeWithPosition(name.Literal, name.TextPosition)
 				if cap(list.Refs) == 0 {
 					list.Refs = p.document.Refs[p.document.NextRefIndex()][:0]
 				}
 				list.Refs = append(list.Refs, ref)
-			} else {
-				p.errUnexpectedToken(p.read())
-				return
-			}
 		default:
-			if acceptIdent {
+			if !acceptAnd {
 				p.errUnexpectedToken(p.read())
 			}
 			return

pkg/astparser/parser_test.go

@@ -927,6 +927,45 @@ func TestParser_Parse(t *testing.T) {
 				}
 			})
 		})
+		// Workaround for graphene issue: https://github.com/graphql-python/graphene/issues/1209
+		t.Run("implements optional variant - comma separated", func(t *testing.T) {
+			run(`type Car implements IVehicle & IMetrics, IWheel {}`, parse, false, func(doc *ast.Document, extra interface{}) {
+				person := doc.ObjectTypeDefinitions[0]
+				personName := doc.Input.ByteSliceString(person.Name)
+				if personName != "Car" {
+					panic("want Car")
+				}
+				// interfaces
+
+				if len(person.ImplementsInterfaces.Refs) != 3 {
+					panic("want 3 interfaces")
+				}
+
+				implementsVehicle := doc.Types[person.ImplementsInterfaces.Refs[0]]
+				if implementsVehicle.TypeKind != ast.TypeKindNamed {
+					panic("want TypeKindNamed")
+				}
+				if doc.Input.ByteSliceString(implementsVehicle.Name) != "IVehicle" {
+					panic("want IVehicle")
+				}
+
+				implementsMetrics := doc.Types[person.ImplementsInterfaces.Refs[1]]
+				if implementsMetrics.TypeKind != ast.TypeKindNamed {
+					panic("want TypeKindNamed")
+				}
+				if doc.Input.ByteSliceString(implementsMetrics.Name) != "IMetrics" {
+					panic("want IMetrics")
+				}
+
+				implementsWheel := doc.Types[person.ImplementsInterfaces.Refs[2]]
+				if implementsWheel.TypeKind != ast.TypeKindNamed {
+					panic("want TypeKindNamed")
+				}
+				if doc.Input.ByteSliceString(implementsWheel.Name) != "IWheel" {
+					panic("want IWheel")
+				}
+			})
+		})
 		t.Run("input value definition list", func(t *testing.T) {
 			run(`	type Person { 
 									"name description"