Fail to parse empty field lists for Object, Interface, and Input Object types

graphql_test.go

@@ -581,6 +581,10 @@ func TestIncludeDirective(t *testing.T) {
 
 type testDeprecatedDirectiveResolver struct{}
 
+func (r *testDeprecatedDirectiveResolver) Test() string {
+	return ""
+}
+
 func (r *testDeprecatedDirectiveResolver) A() int32 {
 	return 0
 }
@@ -643,6 +647,7 @@ func TestDeprecatedDirective(t *testing.T) {
 				}
 
 				type Query {
+					test: String!
 				}
 
 				enum Test {

internal/common/arguments.go

@@ -0,0 +1,38 @@
+package common
+
+type Argument struct {
+	Name  Ident
+	Value Literal
+}
+
+type ArgumentList []Argument
+
+func (l ArgumentList) Get(name string) (Literal, bool) {
+	for _, arg := range l {
+		if arg.Name.Name == name {
+			return arg.Value, true
+		}
+	}
+	return nil, false
+}
+
+func (l ArgumentList) MustGet(name string) Literal {
+	value, ok := l.Get(name)
+	if !ok {
+		panic("argument not found")
+	}
+	return value
+}
+
+func ParseArguments(l *Lexer) ArgumentList {
+	var args ArgumentList
+	l.ConsumeToken('(')
+	for l.Peek() != ')' {
+		name := l.ConsumeIdentWithLoc()
+		l.ConsumeToken(':')
+		value := ParseLiteral(l, false)
+		args = append(args, Argument{Name: name, Value: value})
+	}
+	l.ConsumeToken(')')
+	return args
+}

internal/common/values.go → internal/common/input_values.go

@@ -1,6 +1,8 @@
 package common
 
 import (
+	"fmt"
+
 	"github.com/neelance/graphql-go/errors"
 )
 
@@ -39,39 +41,27 @@ func ParseInputValue(l *Lexer) *InputValue {
 	return p
 }
 
-type Argument struct {
-	Name  Ident
-	Value Literal
-}
-
-type ArgumentList []Argument
-
-func (l ArgumentList) Get(name string) (Literal, bool) {
-	for _, arg := range l {
-		if arg.Name.Name == name {
-			return arg.Value, true
+func ParseArgumentDeclList(l *Lexer) InputValueList {
+	var args InputValueList
+	if l.Peek() == '(' {
+		l.ConsumeToken('(')
+		for l.Peek() != ')' {
+			args = append(args, ParseInputValue(l))
 		}
+		l.ConsumeToken(')')
 	}
-	return nil, false
+	return args
 }
 
-func (l ArgumentList) MustGet(name string) Literal {
-	value, ok := l.Get(name)
-	if !ok {
-		panic("argument not found")
+func ParseInputFieldList(typeName string, l *Lexer) InputValueList {
+	l.ConsumeToken('{')
+	var list InputValueList
+	for l.Peek() != '}' {
+		list = append(list, ParseInputValue(l))
 	}
-	return value
-}
-
-func ParseArguments(l *Lexer) ArgumentList {
-	var args ArgumentList
-	l.ConsumeToken('(')
-	for l.Peek() != ')' {
-		name := l.ConsumeIdentWithLoc()
-		l.ConsumeToken(':')
-		value := ParseLiteral(l, false)
-		args = append(args, Argument{Name: name, Value: value})
+	if len(list) == 0 {
+		l.SyntaxError(fmt.Sprintf(`input type %q must define one or more fields`, typeName))
 	}
-	l.ConsumeToken(')')
-	return args
+	l.ConsumeToken('}')
+	return list
 }

internal/schema/schema.go

@@ -363,18 +363,14 @@ func parseObjectDecl(l *common.Lexer) *Object {
 			}
 		}
 	}
-	l.ConsumeToken('{')
-	o.Fields = parseFields(l)
-	l.ConsumeToken('}')
+	o.Fields = parseFields("object", o.Name, l)
 	return o
 }
 
 func parseInterfaceDecl(l *common.Lexer) *Interface {
 	i := &Interface{}
 	i.Name = l.ConsumeIdent()
-	l.ConsumeToken('{')
-	i.Fields = parseFields(l)
-	l.ConsumeToken('}')
+	i.Fields = parseFields("interface", i.Name, l)
 	return i
 }
 
@@ -393,11 +389,7 @@ func parseUnionDecl(l *common.Lexer) *Union {
 func parseInputDecl(l *common.Lexer) *InputObject {
 	i := &InputObject{}
 	i.Name = l.ConsumeIdent()
-	l.ConsumeToken('{')
-	for l.Peek() != '}' {
-		i.Values = append(i.Values, common.ParseInputValue(l))
-	}
-	l.ConsumeToken('}')
+	i.Values = common.ParseInputFieldList(i.Name, l)
 	return i
 }
 
@@ -420,14 +412,7 @@ func parseDirectiveDecl(l *common.Lexer) *DirectiveDecl {
 	d := &DirectiveDecl{}
 	l.ConsumeToken('@')
 	d.Name = l.ConsumeIdent()
-	if l.Peek() == '(' {
-		l.ConsumeToken('(')
-		for l.Peek() != ')' {
-			v := common.ParseInputValue(l)
-			d.Args = append(d.Args, v)
-		}
-		l.ConsumeToken(')')
-	}
+	d.Args = common.ParseArgumentDeclList(l)
 	l.ConsumeKeyword("on")
 	for {
 		loc := l.ConsumeIdent()
@@ -440,23 +425,22 @@ func parseDirectiveDecl(l *common.Lexer) *DirectiveDecl {
 	return d
 }
 
-func parseFields(l *common.Lexer) FieldList {
+func parseFields(declType, typeName string, l *common.Lexer) FieldList {
 	var fields FieldList
+	l.ConsumeToken('{')
 	for l.Peek() != '}' {
 		f := &Field{}
 		f.Desc = l.DescComment()
 		f.Name = l.ConsumeIdent()
-		if l.Peek() == '(' {
-			l.ConsumeToken('(')
-			for l.Peek() != ')' {
-				f.Args = append(f.Args, common.ParseInputValue(l))
-			}
-			l.ConsumeToken(')')
-		}
+		f.Args = common.ParseArgumentDeclList(l)
 		l.ConsumeToken(':')
 		f.Type = common.ParseType(l)
 		f.Directives = common.ParseDirectives(l)
 		fields = append(fields, f)
 	}
+	if len(fields) == 0 {
+		l.SyntaxError(fmt.Sprintf(`%s type %q must define one or more fields`, declType, typeName))
+	}
+	l.ConsumeToken('}')
 	return fields
 }