bump to go 1.20 + fix some code issues

services/sender.go

@@ -51,14 +51,14 @@ func (s Sender) SendMail(email mail.Email) error {
 	return nil
 }
 
-// watchOutbox reads the `outbox` directory every `TickInterval` and put JSON format e-mail in the queue
+// watchOutbox reads the `outbox` directory every `TickInterval` and put JSON format e-mail in the queue.
 func (s Sender) watchOutbox() {
 	log.Info().Str("outbox", s.outboxPath).Msg("start watching outbox directory")
 
 	ticker := time.NewTicker(TickerInterval)
 
 	go func() {
-		for _ = range ticker.C {
+		for range ticker.C {
 			log.Debug().Str("action", "retrieving json e-mail format...").Str("path", s.outboxPath)
 
 			files, err := os.ReadDir(s.outboxPath)
@@ -69,18 +69,34 @@ func (s Sender) watchOutbox() {
 
 			for _, file := range files {
 				filename := file.Name()
-				if strings.HasSuffix(filename, JSONSuffix) {
-					s.queue.Add(path.Join(s.outboxPath, filename))
+				if !strings.HasSuffix(filename, JSONSuffix) {
+					log.Debug().Str("filename", filename).Msg("incorrect suffix")
 					continue
 				}
 
-				log.Debug().Str("filename", filename).Msg("incorrect suffix")
+				path := path.Join(s.outboxPath, filename)
+				email, err := mail.FromJSON(path)
+
+				if err != nil {
+					log.Err(err).Str("path", path).Msg("unable to parse JSON email")
+
+					// if JSON parsing failed the `path` is renamed with an error suffix to not watch it again
+					newPath := fmt.Sprintf("%s%s", path, ErrorSuffix)
+					if err := os.Rename(path, newPath); err != nil {
+						log.Err(err).Str("path", path).Str("new path", newPath).Msg("unable to rename bad JSON email path")
+					}
+
+					continue
+				}
+
+				email.Path = path
+				s.queue.Add(email)
 			}
 		}
 	}()
 }
 
-// processNextEmail loops over the queue and send email
+// processNextEmail iterates over the queue and send email.
 func (s Sender) processNextEmail() bool {
 	item, quit := s.queue.Get()
 	if quit {
@@ -88,66 +104,56 @@ func (s Sender) processNextEmail() bool {
 	}
 	defer s.queue.Done(item)
 
-	path, ok := item.(string)
+	email, ok := item.(mail.Email)
 	if !ok {
 		log.Error().Any("item", item).Msg("unable to cast queue item into mail.Email")
 		return true
 	}
 
-	email, err := mail.FromJSON(path)
-	if err != nil {
-		log.Err(err).Str("path", path).Msg("unable to parse JSON email")
-
-		// if JSON parsing failed the `path` is renamed with an error suffix to avoid enqueued it again
-		newPath := fmt.Sprintf("%s%s", path, ErrorSuffix)
-		if err := os.Rename(path, newPath); err != nil {
-			log.Err(err).Str("path", path).Str("new path", newPath).Msg("unable to rename bad JSON email path")
-			s.queue.Shutdown()
-		}
-		return true
+	if err := s.SendMail(email); err != nil {
+		log.Err(err).Msg("unable to send the email")
 	}
 
-	// whatever the return, the email will be not enqueued again
-	s.SendMail(email)
-
-	if err := os.Remove(path); err != nil {
-		// this is a fatal error, can't send same e-mail indefinitely
-		if !os.IsExist(err) {
-			log.Err(err).Str("path", path).Msg("unable to remove the JSON email")
-			s.queue.Shutdown()
+	if path := email.Path; path != "" {
+		if err := os.Remove(path); err != nil {
+			// this is a fatal error, can't send same e-mail indefinitely
+			if !os.IsExist(err) {
+				log.Err(err).Str("path", path).Msg("unable to remove the JSON email")
+				s.queue.Shutdown()
+			}
 		}
 	}
 
 	return true
 }
 
-// run starts processing the queue
+// run starts processing the queue.
 func (s Sender) run() <-chan struct{} {
-	queueCh := make(chan struct{})
+	chQueue := make(chan struct{})
 	go func() {
 		for s.processNextEmail() {
 		}
-		queueCh <- struct{}{}
+		chQueue <- struct{}{}
 	}()
-	return queueCh
+	return chQueue
 }
 
-// Run launches the queue processing and the outbox watcher
-// catches `SIGINT` and `SIGTERM` to properly stopped the queue
+// Run launches the queue processing and the outbox watcher.
+// It catches `SIGINT` and `SIGTERM` to properly stopped the queue.
 func (s Sender) Run() {
 	log.Info().Msg("sender service is running")
 
-	sigCh := make(chan os.Signal, 1)
-	signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
+	chSignal := make(chan os.Signal, 1)
+	signal.Notify(chSignal, os.Interrupt, syscall.SIGTERM)
 
 	s.watchOutbox()
-	queueCh := s.run()
+	chQueue := s.run()
 
 	select {
-	case <-sigCh:
+	case <-chSignal:
 		log.Warn().Msg("stop signal received, stopping e-mail queue...")
 		s.queue.Shutdown()
-	case <-queueCh:
+	case <-chQueue:
 		log.Info().Msg("e-mail queue stopped successfully")
 	}