Improved error message when -email-from is empty while sending mail

emailer/smtp.go

@@ -8,6 +8,26 @@ import (
 	mail "github.com/xhit/go-simple-mail/v2"
 )
 
+type SmtpMailErrorCode int
+
+const (
+	EmptyEmailFrom SmtpMailErrorCode = 1 + iota
+)
+
+type SmtpMailError struct {
+	Msg  string
+	Code SmtpMailErrorCode
+}
+
+func (err SmtpMailError) Error() string {
+	switch err.Code {
+	case EmptyEmailFrom:
+		return "-email-from is not specified or is empty.\nCheck the usage with --help."
+	default:
+		panic("Not Implemented")
+	}
+}
+
 type SmtpMail struct {
 	hostname   string
 	port       int
@@ -65,6 +85,10 @@ func (o *SmtpMail) Send(toName string, to string, subject string, content string
 		return err
 	}
 
+	if o.from == "" {
+		return SmtpMailError{Msg: "", Code: EmptyEmailFrom}
+	}
+
 	email := mail.NewMSG()
 	email.SetFrom(addressField(o.from, o.fromName)).
 		AddTo(addressField(to, toName)).

handler/routes.go

@@ -275,6 +275,12 @@ func EmailClient(db store.IStore, mailer emailer.Emailer, emailSubject, emailCon
 		)
 
 		if err != nil {
+			_, isMailError := err.(emailer.SmtpMailError)
+			if isMailError {
+				fmt.Println("SmtpMailError", err)
+				return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, "An error occurred while sending mail. Contact your administrator."})
+			}
+
 			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, err.Error()})
 		}