fix(parser): correctly handle empty documents in multi-document yaml

Author: semihbkgr

parser/parser_test.go

@@ -723,6 +723,20 @@ a:
  b: &anchor null
  c: &anchor2 null
 d: e
+`,
+		},
+		{
+			`
+a: b
+---
+---
+c: d
+`,
+			`
+a: b
+---
+---
+c: d
 `,
 		},
 	}
@@ -1789,6 +1803,9 @@ func (c *pathCapturer) Visit(node ast.Node) ast.Visitor {
 type Visitor struct{}
 
 func (v *Visitor) Visit(node ast.Node) ast.Visitor {
+	if node == nil {
+		return nil
+	}
 	tk := node.GetToken()
 	tk.Prev = nil
 	tk.Next = nil

parser/token.go

@@ -230,7 +230,7 @@ func CreateGroupedTokens(tokens token.Tokens) ([]*Token, error) {
 	if err != nil {
 		return nil, err
 	}
-	tks, err = createDocumentTokens(tks)
+	tks, err = createDocumentTokens(tks, true)
 	if err != nil {
 		return nil, err
 	}
@@ -614,13 +614,13 @@ func createDirectiveTokenGroups(tokens []*Token) ([]*Token, error) {
 	return ret, nil
 }
 
-func createDocumentTokens(tokens []*Token) ([]*Token, error) {
+func createDocumentTokens(tokens []*Token, ignoreHeaderIfAtFirst bool) ([]*Token, error) {
 	var ret []*Token
 	for i := 0; i < len(tokens); i++ {
 		tk := tokens[i]
 		switch tk.Type() {
 		case token.DocumentHeaderType:
-			if i != 0 {
+			if i != 0 || !ignoreHeaderIfAtFirst {
 				ret = append(ret, &Token{
 					Group: &TokenGroup{Tokens: tokens[:i]},
 				})
@@ -634,14 +634,6 @@ func createDocumentTokens(tokens []*Token) ([]*Token, error) {
 					},
 				}), nil
 			}
-			if tokens[i+1].Type() == token.DocumentHeaderType {
-				return append(ret, &Token{
-					Group: &TokenGroup{
-						Type:   TokenGroupDocument,
-						Tokens: []*Token{tk},
-					},
-				}), nil
-			}
 			if tokens[i].Line() == tokens[i+1].Line() {
 				switch tokens[i+1].GroupType() {
 				case TokenGroupMapKey, TokenGroupMapKeyValue:
@@ -652,7 +644,7 @@ func createDocumentTokens(tokens []*Token) ([]*Token, error) {
 					return nil, errors.ErrSyntax("value cannot be placed after document separator", tokens[i+1].RawToken())
 				}
 			}
-			tks, err := createDocumentTokens(tokens[i+1:])
+			tks, err := createDocumentTokens(tokens[i+1:], false)
 			if err != nil {
 				return nil, err
 			}
@@ -683,7 +675,7 @@ func createDocumentTokens(tokens []*Token) ([]*Token, error) {
 				return nil, errors.ErrSyntax("unexpected end content", tokens[i+1].RawToken())
 			}
 
-			tks, err := createDocumentTokens(tokens[i+1:])
+			tks, err := createDocumentTokens(tokens[i+1:], true)
 			if err != nil {
 				return nil, err
 			}