Fix format indent (#653)

* fix indent of formatted text

* add space to origin buffer for implicit null token

Author: goccy

decode_test.go

@@ -3155,10 +3155,15 @@ type bytesUnmershalerWithMapAlias struct{}
 
 func (*bytesUnmershalerWithMapAlias) UnmarshalYAML(b []byte) error {
 	expected := strings.TrimPrefix(`
-stuff:
-  bar:
-    - one
-    - two
+aaaaa:
+  bbbbb:
+    bar:
+      - |
+        foo
+          bar
+      - name: |
+          foo
+            bar
 
 `, "\n")
 	if string(b) != expected {
@@ -3171,11 +3176,16 @@ func TestBytesUnmarshalerWithMapAlias(t *testing.T) {
 	yml := `
 x-foo: &data
   bar:
-    - one
-    - two
+    - |
+      foo
+        bar
+    - name: |
+        foo
+          bar
 
 foo:
-  stuff: *data
+  aaaaa:
+    bbbbb: *data
 `
 	type T struct {
 		Foo bytesUnmershalerWithMapAlias `yaml:"foo"`
@@ -3186,6 +3196,100 @@ foo:
 	}
 }
 
+func TestIssue650(t *testing.T) {
+	type Disk struct {
+		Name   string `yaml:"name"`
+		Format *bool  `yaml:"format"`
+	}
+
+	type Sample struct {
+		Disks []Disk `yaml:"disks"`
+	}
+
+	unmarshalDisk := func(dst *Disk, b []byte) error {
+		var s string
+		if err := yaml.Unmarshal(b, &s); err == nil {
+			*dst = Disk{Name: s}
+			return nil
+		}
+		return yaml.Unmarshal(b, dst)
+	}
+
+	data := []byte(`
+disks:
+    -      name: foo
+           format: true
+`)
+
+	var sample Sample
+	if err := yaml.UnmarshalWithOptions(data, &sample, yaml.CustomUnmarshaler[Disk](unmarshalDisk)); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestBytesUnmarshalerWithLiteral(t *testing.T) {
+	t.Run("map value", func(t *testing.T) {
+		type Literal string
+
+		unmarshalLit := func(dst *Literal, b []byte) error {
+			var s string
+			if err := yaml.Unmarshal(b, &s); err != nil {
+				return err
+			}
+			*dst = Literal(s)
+			return nil
+		}
+
+		data := []byte(`
+-         name:  |
+           foo
+             bar
+-         name:
+           |
+           foo
+           bar
+`)
+
+		var v []map[string]Literal
+		if err := yaml.UnmarshalWithOptions(data, &v, yaml.CustomUnmarshaler[Literal](unmarshalLit)); err != nil {
+			t.Fatal(err)
+		}
+		if !reflect.DeepEqual(v, []map[string]Literal{{"name": "foo\n  bar\n"}, {"name": "foo\nbar\n"}}) {
+			t.Fatalf("failed to get decoded value. got: %q", v)
+		}
+	})
+	t.Run("sequence value", func(t *testing.T) {
+		type Literal string
+
+		unmarshalLit := func(dst *Literal, b []byte) error {
+			var s string
+			if err := yaml.Unmarshal(b, &s); err != nil {
+				return err
+			}
+			*dst = Literal(s)
+			return nil
+		}
+
+		data := []byte(`
+-            |
+  foo
+    bar
+-
+ |
+ foo
+ bar
+`)
+
+		var v []Literal
+		if err := yaml.UnmarshalWithOptions(data, &v, yaml.CustomUnmarshaler[Literal](unmarshalLit)); err != nil {
+			t.Fatal(err)
+		}
+		if !reflect.DeepEqual(v, []Literal{"foo\n  bar\n", "foo\nbar\n"}) {
+			t.Fatalf("failed to get decoded value. got: %q", v)
+		}
+	})
+}
+
 func TestDecoderPreservesDefaultValues(t *testing.T) {
 	type nested struct {
 		Val string `yaml:"val"`

internal/format/format.go

@@ -8,7 +8,7 @@ import (
 )
 
 func FormatNodeWithResolvedAlias(n ast.Node, anchorNodeMap map[string]ast.Node) string {
-	tk := n.GetToken()
+	tk := getFirstToken(n)
 	if tk == nil {
 		return ""
 	}
@@ -18,7 +18,7 @@ func FormatNodeWithResolvedAlias(n ast.Node, anchorNodeMap map[string]ast.Node)
 }
 
 func FormatNode(n ast.Node) string {
-	tk := n.GetToken()
+	tk := getFirstToken(n)
 	if tk == nil {
 		return ""
 	}
@@ -29,7 +29,7 @@ func FormatFile(file *ast.File) string {
 	if len(file.Docs) == 0 {
 		return ""
 	}
-	tk := file.Docs[0].GetToken()
+	tk := getFirstToken(file.Docs[0])
 	if tk == nil {
 		return ""
 	}
@@ -131,6 +131,58 @@ func hasComment(n ast.Node) bool {
 	return false
 }
 
+func getFirstToken(n ast.Node) *token.Token {
+	if n == nil {
+		return nil
+	}
+	switch nn := n.(type) {
+	case *ast.DocumentNode:
+		if nn.Start != nil {
+			return nn.Start
+		}
+		return getFirstToken(nn.Body)
+	case *ast.NullNode:
+		return nn.Token
+	case *ast.BoolNode:
+		return nn.Token
+	case *ast.IntegerNode:
+		return nn.Token
+	case *ast.FloatNode:
+		return nn.Token
+	case *ast.StringNode:
+		return nn.Token
+	case *ast.InfinityNode:
+		return nn.Token
+	case *ast.NanNode:
+		return nn.Token
+	case *ast.LiteralNode:
+		return nn.Start
+	case *ast.DirectiveNode:
+		return nn.Start
+	case *ast.TagNode:
+		return nn.Start
+	case *ast.MappingNode:
+		if nn.IsFlowStyle {
+			return nn.Start
+		}
+		if len(nn.Values) == 0 {
+			return nn.Start
+		}
+		return getFirstToken(nn.Values[0].Key)
+	case *ast.MappingKeyNode:
+		return nn.Start
+	case *ast.MergeKeyNode:
+		return nn.Token
+	case *ast.SequenceNode:
+		return nn.Start
+	case *ast.AnchorNode:
+		return nn.Start
+	case *ast.AliasNode:
+		return nn.Start
+	}
+	return nil
+}
+
 type Formatter struct {
 	existsComment    bool
 	tokenToOriginMap map[*token.Token]string
@@ -155,17 +207,66 @@ func newFormatter(tk *token.Token, existsComment bool) *Formatter {
 		tokenToOriginMap[tk] = origin
 		origin = ""
 	}
-
 	return &Formatter{
 		existsComment:    existsComment,
 		tokenToOriginMap: tokenToOriginMap,
 	}
 }
 
+func getIndentNumByFirstLineToken(tk *token.Token) int {
+	defaultIndent := tk.Position.Column - 1
+
+	// key: value
+	//    ^
+	//   next
+	if tk.Type == token.SequenceEntryType {
+		// If the current token is the sequence entry.
+		// the indent is calculated from the column value of the current token.
+		return defaultIndent
+	}
+
+	// key: value
+	//    ^
+	//   next
+	if tk.Next != nil && tk.Next.Type == token.MappingValueType {
+		// If the current token is the key in the mapping-value,
+		// the indent is calculated from the column value of the current token.
+		return defaultIndent
+	}
+
+	if tk.Prev == nil {
+		return defaultIndent
+	}
+	prev := tk.Prev
+
+	// key: value
+	//    ^
+	//   prev
+	if prev.Type == token.MappingValueType {
+		// If the current token is the value in the mapping-value,
+		// the indent is calculated from the column value of the key two steps back.
+		if prev.Prev == nil {
+			return defaultIndent
+		}
+		return prev.Prev.Position.Column - 1
+	}
+
+	// - value
+	// ^
+	// prev
+	if prev.Type == token.SequenceEntryType {
+		// If the value is not a mapping-value and the previous token was a sequence entry,
+		// the indent is calculated using the column value of the sequence entry token.
+		return prev.Position.Column - 1
+	}
+
+	return defaultIndent
+}
+
 func (f *Formatter) format(n ast.Node) string {
 	return f.trimSpacePrefix(
 		f.trimIndentSpace(
-			n.GetToken().Position.IndentNum,
+			getIndentNumByFirstLineToken(getFirstToken(n)),
 			f.trimNewLineCharPrefix(f.formatNode(n)),
 		),
 	)
@@ -306,7 +407,8 @@ func (f *Formatter) formatAnchor(n *ast.AnchorNode) string {
 
 func (f *Formatter) formatAlias(n *ast.AliasNode) string {
 	if f.anchorNodeMap != nil {
-		node := f.anchorNodeMap[n.Value.GetToken().Value]
+		anchorName := n.Value.GetToken().Value
+		node := f.anchorNodeMap[anchorName]
 		if node != nil {
 			formatted := f.formatNode(node)
 			// If formatted text contains newline characters, indentation needs to be considered.

parser/context.go

@@ -132,7 +132,6 @@ func (c *context) addNullValueToken(tk *Token) *Token {
 	rawTk := nullToken.RawToken()
 
 	// add space for map or sequence value.
-	rawTk.Origin = " null"
 	rawTk.Position.Column++
 
 	c.addToken(nullToken)
@@ -144,7 +143,7 @@ func (c *context) addNullValueToken(tk *Token) *Token {
 func (c *context) createNullToken(base *Token) *Token {
 	pos := *(base.RawToken().Position)
 	pos.Column++
-	return &Token{Token: token.New("null", "null", &pos)}
+	return &Token{Token: token.New("null", " null", &pos)}
 }
 
 func (c *context) insertToken(tk *Token) {