From 2e4f5e8cfc966fe29cac87dac337acd70ac3e15c Mon Sep 17 00:00:00 2001
From: ADITYA TIWARI <adityatiwari342005@gmail.com>
Date: Mon, 15 Dec 2025 12:38:12 +0000
Subject: [PATCH] promql/parser: consolidate label quoting logic refactors
 binary expression formatting to reuse writeLabels() instead of maintaining
 separate joinLabels() function. adds comprehensive UTF-8 label tests for all
 expression types

Signed-off-by: ADITYA TIWARI <adityatiwari342005@gmail.com>
---
 promql/parser/printer.go      | 32 +++++++++++++++++---------------
 promql/parser/printer_test.go | 18 ++++++++++++++++++
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/promql/parser/printer.go b/promql/parser/printer.go
index 67b13eaf12..cca04ae222 100644
--- a/promql/parser/printer.go
+++ b/promql/parser/printer.go
@@ -145,21 +145,9 @@ func (node *BinaryExpr) ShortString() string {
 	return node.Op.String() + node.returnBool() + node.getMatchingStr()
 }
 
-// joinLabels joins label names, quoting them if they are not valid legacy label names.
-func joinLabels(labels []string) string {
-	quoted := make([]string, 0, len(labels))
-	for _, label := range labels {
-		if model.LegacyValidation.IsValidLabelName(label) {
-			quoted = append(quoted, label)
-		} else {
-			quoted = append(quoted, strconv.Quote(label))
-		}
-	}
-	return strings.Join(quoted, ", ")
-}
-
 func (node *BinaryExpr) getMatchingStr() string {
 	matching := ""
+	var b bytes.Buffer
 	vm := node.VectorMatching
 	if vm != nil {
 		if len(vm.MatchingLabels) > 0 || vm.On || vm.Card == CardManyToOne || vm.Card == CardOneToMany {
@@ -167,7 +155,14 @@ func (node *BinaryExpr) getMatchingStr() string {
 			if vm.On {
 				vmTag = "on"
 			}
-			matching = fmt.Sprintf(" %s (%s)", vmTag, joinLabels(vm.MatchingLabels))
+			// Use writeLabels() instead of joinLabels()
+			b.Reset()
+			b.WriteString(" ")
+			b.WriteString(vmTag)
+			b.WriteString(" (")
+			writeLabels(&b, vm.MatchingLabels)
+			b.WriteString(")")
+			matching = b.String()
 		}
 
 		if vm.Card == CardManyToOne || vm.Card == CardOneToMany {
@@ -175,7 +170,14 @@ func (node *BinaryExpr) getMatchingStr() string {
 			if vm.Card == CardManyToOne {
 				vmCard = "left"
 			}
-			matching += fmt.Sprintf(" group_%s (%s)", vmCard, joinLabels(vm.Include))
+			// Use writeLabels() instead of joinLabels()
+			b.Reset()
+			b.WriteString(" group_")
+			b.WriteString(vmCard)
+			b.WriteString(" (")
+			writeLabels(&b, vm.Include)
+			b.WriteString(")")
+			matching += b.String()
 		}
 	}
 	return matching
diff --git a/promql/parser/printer_test.go b/promql/parser/printer_test.go
index c9a3cb35e8..31e707ee96 100644
--- a/promql/parser/printer_test.go
+++ b/promql/parser/printer_test.go
@@ -273,6 +273,14 @@ func TestExprString(t *testing.T) {
 			in:  `sum by("üüü") (foo)`,
 			out: `sum by ("üüü") (foo)`,
 		},
+		{
+			in:  `sum without("äää") (foo)`,
+			out: `sum without ("äää") (foo)`,
+		},
+		{
+			in:  `count by("ööö", job) (foo)`,
+			out: `count by ("ööö", job) (foo)`,
+		},
 	}
 
 	EnableExtendedRangeSelectors = true
@@ -410,11 +418,21 @@ func TestBinaryExprUTF8Labels(t *testing.T) {
 			input:    `foo / on("äää") bar`,
 			expected: `foo / on ("äää") bar`,
 		},
+		{
+			name:     "UTF-8 labels in ignoring clause",
+			input:    `foo / ignoring("üüü") bar`,
+			expected: `foo / ignoring ("üüü") bar`,
+		},
 		{
 			name:     "UTF-8 labels in group_left clause",
 			input:    `foo / on("äää") group_left("ööö") bar`,
 			expected: `foo / on ("äää") group_left ("ööö") bar`,
 		},
+		{
+			name:     "UTF-8 labels in group_right clause",
+			input:    `foo / on("äää") group_right("ööö") bar`,
+			expected: `foo / on ("äää") group_right ("ööö") bar`,
+		},
 		{
 			name:     "Mixed legacy and UTF-8 labels",
 			input:    `foo / on(legacy, "üüü") bar`,