Use a strings.Builder in Peer.String with explicit nil fields

Signed-off-by: Yolan Romailler <anomalroil@users.noreply.github.com>

peer/peer.go

@@ -24,6 +24,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"strings"
 
 	"google.golang.org/grpc/credentials"
 )
@@ -46,18 +47,21 @@ func (p *Peer) String() string {
 	if p == nil {
 		return "Peer<nil>"
 	}
-	ret := "Peer{"
+	sb := &strings.Builder{}
+	sb.WriteString("Peer{")
 	if p.Addr != nil {
-		ret += fmt.Sprintf("Addr: '%s'", p.Addr.String())
+		fmt.Fprintf(sb, "Addr: '%s', ", p.Addr.String())
+	} else {
+		fmt.Fprintf(sb, "Addr: <nil>, ")
 	}
 	if p.AuthInfo != nil {
-		if len(ret) > 5 {
-			ret += ", "
-		}
-		ret += fmt.Sprintf("AuthInfo: '%s'", p.AuthInfo.AuthType())
+		fmt.Fprintf(sb, "AuthInfo: '%s'", p.AuthInfo.AuthType())
+	} else {
+		fmt.Fprintf(sb, "AuthInfo: <nil>")
 	}
-	ret += "}"
-	return ret
+	sb.WriteString("}")
+
+	return sb.String()
 }
 
 type peerKey struct{}

peer/peer_test.go

@@ -103,15 +103,15 @@ func TestPeerStringer(t *testing.T) {
 		{
 			addr:      &addr{"1.2.3.4:1234"},
 			authLevel: -1,
-			want:      "Peer{Addr: '1.2.3.4:1234'}",
+			want:      "Peer{Addr: '1.2.3.4:1234', AuthInfo: <nil>}",
 		},
 		{
 			authLevel: credentials.InvalidSecurityLevel,
-			want:      "Peer{AuthInfo: 'testAuthInfo'}",
+			want:      "Peer{Addr: <nil>, AuthInfo: 'testAuthInfo'}",
 		},
 		{
 			authLevel: -1,
-			want:      "Peer{}",
+			want:      "Peer{Addr: <nil>, AuthInfo: <nil>}",
 		},
 	}
 	for _, tc := range testCases {