init

.golangci.yaml

@@ -9,6 +9,8 @@ linters:
     - mnd
     - exportloopref
     - err113
+    - tparallel
+    - paralleltest
 
 issues:
   exclude-rules:

internal/email/client.go

@@ -55,7 +55,7 @@ func (client *Client) SendEmail(ctx context.Context, email *Email) error {
 
 		err = json.NewDecoder(resp.Body).Decode(&commError)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to decode error response: %w", err)
 		}
 
 		return fmt.Errorf("status code: %d, error message: %s", resp.StatusCode, commError.Error.Message)

internal/email/types.go

@@ -13,21 +13,21 @@ type Client struct {
 }
 
 type Email struct {
-	Recipients    Recipients     `json:"recipients"`
-	SenderAddress string         `json:"senderAddress"`
-	Content       Content        `json:"content"`
-	Tracking      bool           `json:"disableUserEngagementTracking"`
-	Importance    string         `json:"importance"`
-	ReplyTo       []EmailAddress `json:"replyTo"`
+	Recipients    Recipients `json:"recipients"`
+	SenderAddress string     `json:"senderAddress"`
+	Content       Content    `json:"content"`
+	Tracking      bool       `json:"disableUserEngagementTracking"`
+	Importance    string     `json:"importance"`
+	ReplyTo       []Address  `json:"replyTo"`
 }
 
 type Recipients struct {
-	To  []EmailAddress `json:"to"`
-	CC  []EmailAddress `json:"cc"`
-	BCC []EmailAddress `json:"bcc"`
+	To  []Address `json:"to"`
+	CC  []Address `json:"cc"`
+	BCC []Address `json:"bcc"`
 }
 
-type EmailAddress struct {
+type Address struct {
 	DisplayName string `json:"displayName"`
 	Address     string `json:"address"`
 }
@@ -42,7 +42,7 @@ type ErrorResponse struct {
 	Error CommunicationError `json:"error"`
 }
 
-// CommunicationError contains the error code and message
+// CommunicationError contains the error code and message.
 type CommunicationError struct {
 	Code    string `json:"code"`
 	Message string `json:"message"`

internal/smtp/server.go

@@ -110,6 +110,8 @@ func (s *Server) Shutdown() error {
 }
 
 // handleConnection processes an SMTP client connection.
+//
+//nolint:gocognit
 func (s *Server) handleConnection(conn net.Conn) error {
 	var (
 		err      error
@@ -316,8 +318,8 @@ func parseMailData(data string) (*MailMessage, error) {
 		return ""
 	}
 
-	from := getHeader("From")
-	to := getHeader("To")
+	mailFrom := getHeader("From")
+	mailTo := getHeader("To")
 	subject := getHeader("Subject")
 
 	contentType := getHeader("Content-Type")
@@ -328,8 +330,8 @@ func parseMailData(data string) (*MailMessage, error) {
 	}
 
 	mailMessage := &MailMessage{
-		From:    from,
-		To:      to,
+		From:    mailFrom,
+		To:      mailTo,
 		Subject: subject,
 	}
 

internal/smtp/server_test.go

@@ -108,7 +108,7 @@ Your Name`,
 
 			msg := []byte(fmt.Sprintf("From: %s\r\nTo: %s\r\n"+
 				"Subject: %s\r\n"+
-				"%s\r\n", test.from, test.to, test.subject, test.body))
+				"%s\r\n", test.from, test.to, test.subject, body))
 
 			err := smtp.SendMail("localhost:1515", nil, test.from, []string{test.to}, msg)
 			require.NoError(t, err)

main.go

@@ -67,8 +67,11 @@ func run(logger *slog.Logger) error {
 		return emailClient.SendEmail(context.Background(), &email.Email{
 			SenderAddress: mail.From,
 			Recipients: email.Recipients{
-				To: []email.EmailAddress{
-					{mail.To, mail.To},
+				To: []email.Address{
+					{
+						Address:     mail.To,
+						DisplayName: mail.To,
+					},
 				},
 			},
 			Content: email.Content{