fix(lint): avoid string concat in loop

Signed-off-by: Chris Gianelloni <wolf31o2@blinklabs.io>

Author: wolf31o2

internal/dns/dns.go

@@ -552,9 +552,10 @@ func randomFallbackServer() string {
 }
 
 func formatMessageAnswerSection(section []dns.RR) string {
-	ret := "[ "
+	var ret strings.Builder
+	ret.WriteString("[ ")
 	for idx, rr := range section {
-		ret += fmt.Sprintf(
+		ret.WriteString(fmt.Sprintf(
 			"< %s >",
 			strings.ReplaceAll(
 				strings.TrimPrefix(
@@ -564,20 +565,21 @@ func formatMessageAnswerSection(section []dns.RR) string {
 				"\t",
 				" ",
 			),
-		)
+		))
 		if idx != len(section)-1 {
-			ret += `,`
+			ret.WriteString(`,`)
 		}
-		ret += ` `
+		ret.WriteString(` `)
 	}
-	ret += "]"
-	return ret
+	ret.WriteString("]")
+	return ret.String()
 }
 
 func formatMessageQuestionSection(section []dns.Question) string {
-	ret := "[ "
+	var ret strings.Builder
+	ret.WriteString("[ ")
 	for idx, question := range section {
-		ret += fmt.Sprintf(
+		ret.WriteString(fmt.Sprintf(
 			"< %s >",
 			strings.ReplaceAll(
 				strings.TrimPrefix(
@@ -587,12 +589,12 @@ func formatMessageQuestionSection(section []dns.Question) string {
 				"\t",
 				" ",
 			),
-		)
+		))
 		if idx != len(section)-1 {
-			ret += `,`
+			ret.WriteString(`,`)
 		}
-		ret += ` `
+		ret.WriteString(` `)
 	}
-	ret += "]"
-	return ret
+	ret.WriteString("]")
+	return ret.String()
 }

internal/handshake/domain.go

@@ -13,6 +13,7 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"strings"
 )
 
 const (
@@ -297,6 +298,7 @@ func domainRecordNameDecode(r *BytesReader) (string, error) {
 			if c > DnsMaxLabel {
 				return "", errors.New("label too long")
 			}
+			var sb strings.Builder
 			for range int(c) {
 				b, err := r.ReadByte()
 				if err != nil {
@@ -311,8 +313,9 @@ func domainRecordNameDecode(r *BytesReader) (string, error) {
 				if b == 0x2e {
 					b = 0xfe
 				}
-				name += string([]byte{b})
+				sb.WriteString(string([]byte{b}))
 			}
+			name += sb.String()
 			if len(name) > 0 {
 				name += "."
 			}