Merge b78119772a into e2f1d5ccf7

pkg/yqlib/decoder_toml.go

@@ -157,9 +157,25 @@ func (dec *tomlDecoder) createInlineTableMap(tomlNode *toml.Node) (*CandidateNod
 	}, nil
 }
 
+// commentIsOnNewLine reports whether comment begins on a line after the end of
+// prev, by scanning the raw input bytes between them for a newline. When the
+// range cannot be determined it returns true, preserving the historic behaviour
+// of treating in-array comments as head comments for the next element.
+func (dec *tomlDecoder) commentIsOnNewLine(prev, comment *toml.Node) bool {
+	prevEnd := prev.Raw.Offset + prev.Raw.Length
+	commentStart := comment.Raw.Offset
+	if commentStart < prevEnd {
+		return true
+	}
+	between := dec.parser.Raw(toml.Range{Offset: prevEnd, Length: commentStart - prevEnd})
+	return bytes.IndexByte(between, '\n') >= 0
+}
+
 func (dec *tomlDecoder) createArray(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := make([]*CandidateNode, 0)
 	var pendingArrayComments []string
+	var prevElem *toml.Node
+	var prevYamlNode *CandidateNode
 
 	iterator := tomlNode.Children()
 	for iterator.Next() {
@@ -167,8 +183,19 @@ func (dec *tomlDecoder) createArray(tomlNode *toml.Node) (*CandidateNode, error)
 
 		// Handle comments within arrays
 		if child.Kind == toml.Comment {
+			// A comment on the same line as the preceding element is a trailing
+			// (inline) comment on that element; a comment on its own line is a
+			// head comment for the next element.
+			if prevYamlNode != nil && !dec.commentIsOnNewLine(prevElem, child) {
+				if prevYamlNode.LineComment == "" {
+					prevYamlNode.LineComment = string(child.Data)
+				} else {
+					prevYamlNode.LineComment = prevYamlNode.LineComment + "\n" + string(child.Data)
+				}
+			} else {
 				// Collect comments to attach to the next array element
 				pendingArrayComments = append(pendingArrayComments, string(child.Data))
+			}
 			continue
 		}
 
@@ -184,6 +211,8 @@ func (dec *tomlDecoder) createArray(tomlNode *toml.Node) (*CandidateNode, error)
 		}
 
 		content = append(content, yamlNode)
+		prevElem = child
+		prevYamlNode = yamlNode
 	}
 
 	return &CandidateNode{

pkg/yqlib/encoder_toml.go

@@ -188,6 +188,10 @@ func (te *tomlEncoder) encodeTopLevelEntry(w io.Writer, path []string, node *Can
 				te.wroteRootAttr = false
 			}
 			for _, it := range node.Content {
+				// Write head comment before the array-of-tables header
+				if err := te.writeComment(w, it.HeadComment); err != nil {
+					return err
+				}
 				if _, err := w.Write([]byte("[[" + quotedKey + "]]\n")); err != nil {
 					return err
 				}
@@ -283,10 +287,10 @@ func (te *tomlEncoder) writeArrayAttribute(w io.Writer, key string, seq *Candida
 		return err
 	}
 
-	// Check if any array elements have head comments - if so, use multiline format
+	// Check if any array elements have head or line comments - if so, use multiline format
 	hasElementComments := false
 	for _, it := range seq.Content {
-		if it.HeadComment != "" {
+		if it.HeadComment != "" || it.LineComment != "" {
 			hasElementComments = true
 			break
 		}
@@ -299,6 +303,13 @@ func (te *tomlEncoder) writeArrayAttribute(w io.Writer, key string, seq *Candida
 		}
 
 		for i, it := range seq.Content {
+			// Separate a head-commented element from the previous one with a blank line
+			if i > 0 && it.HeadComment != "" {
+				if _, err := w.Write([]byte("\n")); err != nil {
+					return err
+				}
+			}
+
 			// Write head comment for this element
 			if it.HeadComment != "" {
 				commentLines := strings.Split(it.HeadComment, "\n")
@@ -340,17 +351,19 @@ func (te *tomlEncoder) writeArrayAttribute(w io.Writer, key string, seq *Candida
 			// Always add trailing comma in multiline arrays
 			itemStr += ","
 
-			if _, err := w.Write([]byte("  " + itemStr + "\n")); err != nil {
+			// Append trailing (inline) comment on the same line, if present
-				return err
+			if it.LineComment != "" {
+				lineComment := strings.TrimSpace(it.LineComment)
+				if !strings.HasPrefix(lineComment, "#") {
+					lineComment = "# " + lineComment
+				}
+				itemStr += "  " + lineComment
 			}
 
-			// Add blank line between elements (except after the last one)
+			if _, err := w.Write([]byte("  " + itemStr + "\n")); err != nil {
-			if i < len(seq.Content)-1 {
-				if _, err := w.Write([]byte("\n")); err != nil {
 				return err
 			}
 		}
-		}
 
 		if _, err := w.Write([]byte("]\n")); err != nil {
 			return err
@@ -546,6 +559,10 @@ func (te *tomlEncoder) encodeSeparateMapping(w io.Writer, path []string, m *Cand
 					te.wroteRootAttr = false
 				}
 				for _, it := range v.Content {
+					// Write head comment before the array-of-tables header
+					if err := te.writeComment(w, it.HeadComment); err != nil {
+						return err
+					}
 					if _, err := w.Write([]byte("[[" + key + "]]\n")); err != nil {
 						return err
 					}
@@ -603,6 +620,10 @@ func (te *tomlEncoder) encodeMappingBodyWithPath(w io.Writer, path []string, m *
 			if isTomlArrayOfTables(v) {
 				dotted := tomlDottedKey(append(append([]string{}, path...), k))
 				for _, it := range v.Content {
+					// Write head comment before the array-of-tables header
+					if err := te.writeComment(w, it.HeadComment); err != nil {
+						return err
+					}
 					if _, err := w.Write([]byte("[[" + dotted + "]]\n")); err != nil {
 						return err
 					}

pkg/yqlib/toml_test.go

@@ -325,6 +325,33 @@ the_array = [
 ]
 `
 
+// Bug: a head comment directly above an [[array-of-tables]] header is dropped
+// on round-trip when other content precedes the array-of-tables.
+var rtArrayTableHeadComment = `[package]
+name = "x"
+
+# the binary
+[[bin]]
+name = "y"
+`
+
+// Same bug via a nested array-of-tables ([[a.b]]) under a table with attributes.
+var rtNestedArrayTableHeadComment = `[fruit]
+name = "apple"
+# a variety
+[[fruit.variety]]
+name = "red delicious"
+`
+
+// Bug: an inline (trailing) comment on an array item detaches from its item and
+// floats onto its own line as a head comment on the next item, with a spurious
+// blank line.
+var rtArrayItemInlineComment = `default = [
+  "a",  # why a
+  "b",
+]
+`
+
 var expectedSubArrays = `array:
   - subarray:
       - subsubarray:
@@ -369,7 +396,7 @@ var tomlScenarios = []formatScenario{
 		skipDoc:       true,
 		description:   "blank",
 		input:         `A = "hello`,
-		expectedError: `bad file 'sample.yml': basic string not terminated by "`,
+		expectedError: `bad file 'sample.yml': unterminated basic string`,
 		scenarioType:  "decode-error",
 	},
 	{
@@ -700,6 +727,30 @@ var tomlScenarios = []formatScenario{
 		expected:     tomlTableWithComments,
 		scenarioType: "roundtrip",
 	},
+	{
+		skipDoc:      true,
+		description:  "Roundtrip: head comment above array-of-tables",
+		input:        rtArrayTableHeadComment,
+		expression:   ".",
+		expected:     rtArrayTableHeadComment,
+		scenarioType: "roundtrip",
+	},
+	{
+		skipDoc:      true,
+		description:  "Roundtrip: head comment above nested array-of-tables",
+		input:        rtNestedArrayTableHeadComment,
+		expression:   ".",
+		expected:     rtNestedArrayTableHeadComment,
+		scenarioType: "roundtrip",
+	},
+	{
+		skipDoc:      true,
+		description:  "Roundtrip: inline comment on array item",
+		input:        rtArrayItemInlineComment,
+		expression:   ".",
+		expected:     rtArrayItemInlineComment,
+		scenarioType: "roundtrip",
+	},
 	// Encode (YAML → TOML) scenarios - verify readable table sections are produced
 	{
 		description:  "Encode: Simple mapping produces table section",