SMTP client tests overhaul

senderror_test.go

@@ -174,6 +174,12 @@ func TestSendError_MessageID(t *testing.T) {
 			t.Errorf("sendError expected empty message-id, got: %s", sendErr.MessageID())
 		}
 	})
+	t.Run("TestSendError_MessageID on nil error should return empty", func(t *testing.T) {
+		var sendErr *SendError
+		if sendErr.MessageID() != "" {
+			t.Error("expected empty message-id on nil-senderror")
+		}
+	})
 }
 
 func TestSendError_Msg(t *testing.T) {

smtp/auth_login.go

@@ -36,8 +36,8 @@ type loginAuth struct {
 // LoginAuth will only send the credentials if the connection is using TLS
 // or is connected to localhost. Otherwise authentication will fail with an
 // error, without sending the credentials.
-func LoginAuth(username, password, host string, allowUnEnc bool) Auth {
-	return &loginAuth{username, password, host, 0, allowUnEnc}
+func LoginAuth(username, password, host string, allowUnenc bool) Auth {
+	return &loginAuth{username, password, host, 0, allowUnenc}
 }
 
 // Start begins the SMTP authentication process by validating server's TLS status and hostname.

smtp/auth_plain.go

@@ -28,8 +28,8 @@ type plainAuth struct {
 // PlainAuth will only send the credentials if the connection is using TLS
 // or is connected to localhost. Otherwise authentication will fail with an
 // error, without sending the credentials.
-func PlainAuth(identity, username, password, host string, allowUnEnc bool) Auth {
-	return &plainAuth{identity, username, password, host, allowUnEnc}
+func PlainAuth(identity, username, password, host string, allowUnenc bool) Auth {
+	return &plainAuth{identity, username, password, host, allowUnenc}
 }
 
 func (a *plainAuth) Start(server *ServerInfo) (string, []byte, error) {

smtp/auth_scram.go

@@ -154,7 +154,7 @@ func (a *scramAuth) initialClientMessage() ([]byte, error) {
 		connState := a.tlsConnState
 		bindData := connState.TLSUnique
 
-		// crypto/tl: no tls-unique channel binding value for this tls connection, possibly due to missing
+		// crypto/tls: no tls-unique channel binding value for this tls connection, possibly due to missing
 		// extended master key support and/or resumed connection
 		// RFC9266:122 tls-unique not defined for tls 1.3 and later
 		if bindData == nil || connState.Version >= tls.VersionTLS13 {
@@ -308,10 +308,7 @@ func (a *scramAuth) normalizeUsername() (string, error) {
 func (a *scramAuth) normalizeString(s string) (string, error) {
 	s, err := precis.OpaqueString.String(s)
 	if err != nil {
-		return "", fmt.Errorf("failled to normalize string: %w", err)
-	}
-	if s == "" {
-		return "", errors.New("normalized string is empty")
+		return "", fmt.Errorf("failed to normalize string: %w", err)
 	}
 	return s, nil
 }

smtp/smtp.go

@@ -587,7 +587,9 @@ func (c *Client) SetLogger(l log.Logger) {
 	if l == nil {
 		return
 	}
+	c.mutex.Lock()
 	c.logger = l
+	c.mutex.Unlock()
 }
 
 // SetLogAuthData enables logging of authentication data in the Client.
@@ -620,6 +622,9 @@ func (c *Client) HasConnection() bool {
 func (c *Client) UpdateDeadline(timeout time.Duration) error {
 	c.mutex.Lock()
 	defer c.mutex.Unlock()
+	if c.conn == nil {
+		return errors.New("smtp: client has no connection")
+	}
 	if err := c.conn.SetDeadline(time.Now().Add(timeout)); err != nil {
 		return fmt.Errorf("smtp: failed to update deadline: %w", err)
 	}

smtp/smtp_121_test.go

@@ -0,0 +1,59 @@
+// SPDX-FileCopyrightText: Copyright 2010 The Go Authors. All rights reserved.
+// SPDX-FileCopyrightText: Copyright (c) 2022-2023 The go-mail Authors
+//
+// Original net/smtp code from the Go stdlib by the Go Authors.
+// Use of this source code is governed by a BSD-style
+// LICENSE file that can be found in this directory.
+//
+// go-mail specific modifications by the go-mail Authors.
+// Licensed under the MIT License.
+// See [PROJECT ROOT]/LICENSES directory for more information.
+//
+// SPDX-License-Identifier: BSD-3-Clause AND MIT
+
+//go:build go1.21
+// +build go1.21
+
+package smtp
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/wneessen/go-mail/log"
+)
+
+func TestClient_SetDebugLog_JSON(t *testing.T) {
+	t.Run("set debug loggging to on should not override logger", func(t *testing.T) {
+		client := &Client{logger: log.NewJSON(os.Stderr, log.LevelDebug)}
+		client.SetDebugLog(true)
+		if !client.debug {
+			t.Fatalf("expected debug log to be true")
+		}
+		if client.logger == nil {
+			t.Fatalf("expected logger to be defined")
+		}
+		if !strings.EqualFold(fmt.Sprintf("%T", client.logger), "*log.JSONlog") {
+			t.Errorf("expected logger to be of type *log.JSONlog, got: %T", client.logger)
+		}
+	})
+}
+
+func TestClient_SetLogger_JSON(t *testing.T) {
+	t.Run("set logger to JSONlog logger", func(t *testing.T) {
+		client := &Client{}
+		client.SetLogger(log.NewJSON(os.Stderr, log.LevelDebug))
+		if !strings.EqualFold(fmt.Sprintf("%T", client.logger), "*log.JSONlog") {
+			t.Errorf("expected logger to be of type *log.JSONlog, got: %T", client.logger)
+		}
+	})
+	t.Run("nil logger should just return and not set/override", func(t *testing.T) {
+		client := &Client{logger: log.NewJSON(os.Stderr, log.LevelDebug)}
+		client.SetLogger(nil)
+		if !strings.EqualFold(fmt.Sprintf("%T", client.logger), "*log.JSONlog") {
+			t.Errorf("expected logger to be of type *log.JSONlog, got: %T", client.logger)
+		}
+	})
+}