From 5b5dc2ea955dee6743114de260be42583ff2158d Mon Sep 17 00:00:00 2001
From: William Banfield <wbanfield@gmail.com>
Date: Wed, 11 May 2022 10:12:54 -0400
Subject: [PATCH] use strings.Builder

---
 scripts/metricsgen/metricsdiff/metricsdiff.go | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/scripts/metricsgen/metricsdiff/metricsdiff.go b/scripts/metricsgen/metricsdiff/metricsdiff.go
index 0be1dc55b..eff14edeb 100644
--- a/scripts/metricsgen/metricsdiff/metricsdiff.go
+++ b/scripts/metricsgen/metricsdiff/metricsdiff.go
@@ -10,6 +10,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
@@ -130,30 +131,30 @@ func toSet(lps []*dto.LabelPair) map[string]struct{} {
 }
 
 func (m Diff) String() string {
-	var s string
+	var s strings.Builder
 	if len(m.Adds) > 0 {
-		s += "Adds: \n"
+		fmt.Fprintln(&s, "Adds:")
 		for _, add := range m.Adds {
-			s += fmt.Sprintf("+++ %s\n", add)
+			fmt.Fprintf(&s, "+++ %s\n", add)
 		}
 	}
 	if len(m.Removes) > 0 {
-		s += "Removes: \n"
-		for _, remove := range m.Removes {
-			s += fmt.Sprintf("--- %s\n", remove)
+		fmt.Fprintln(&s, "Removes:")
+		for _, rem := range m.Removes {
+			fmt.Fprintf(&s, "--- %s\n", rem)
 		}
 	}
 	if len(m.Changes) > 0 {
-		s += "Label Changes: \n"
+		fmt.Fprintln(&s, "Label changes:")
 		for _, ld := range m.Changes {
-			s += fmt.Sprintf("Label: %s\n", ld.Metric)
+			fmt.Fprintf(&s, "Label: %s\n", ld.Metric)
 			for _, add := range ld.Adds {
-				s += fmt.Sprintf("+++ %s", add)
+				fmt.Fprintf(&s, "+++ %s\n", add)
 			}
-			for _, remove := range ld.Removes {
-				s += fmt.Sprintf("--- %s", remove)
+			for _, rem := range ld.Removes {
+				fmt.Fprintf(&s, "--- %s\n", rem)
 			}
 		}
 	}
-	return s
+	return s.String()
 }