Add ability to add custom_args into req payload

Author: pthieu

api/notification-service.yaml

@@ -268,6 +268,15 @@ components:
           type: array
           items:
             type: string
+        customArgs:
+          type: object
+          additionalProperties:
+            type: string
+          description: |
+            Custom arguments are key/value pairs passed to the mail provider.
+            These will be passed through to the mail provider and can be used to provide additional information about the message.
+            For example, if the mail provider is SendGrid, these will be passed through as custom_args.
+          
 
     SendBulkMailRequest:
       type: object

internal/mail/mail.go

@@ -29,7 +29,7 @@ func SendBulkMail(toList []server.EmailRecipient, from server.EmailSender, cc []
 	// Create goroutines for each send
 	for _, to := range toList {
 		go func(to server.EmailRecipient) {
-			response, err := SendIndividualMail([]server.EmailRecipient{to}, from, cc, bcc, headers, message, client, []string{})
+			response, err := SendIndividualMail([]server.EmailRecipient{to}, from, cc, bcc, headers, message, client, []string{}, map[string]string{})
 			responseChannel <- BulkSendAttempt{to.Address, response, err}
 			wg.Done()
 		}(to)
@@ -42,7 +42,7 @@ func SendBulkMail(toList []server.EmailRecipient, from server.EmailSender, cc []
 }
 
 // SendIndividualMail sends an email message
-func SendIndividualMail(to []server.EmailRecipient, from server.EmailSender, cc []server.EmailRecipient, bcc []server.EmailRecipient, headers map[string]string, message server.MailMessage, client Client, tags []string) (*rest.Response, error) {
+func SendIndividualMail(to []server.EmailRecipient, from server.EmailSender, cc []server.EmailRecipient, bcc []server.EmailRecipient, headers map[string]string, message server.MailMessage, client Client, tags []string, customArgs map[string]string) (*rest.Response, error) {
 	sendMessage := sendgridMail.NewV3Mail()
 
 	sendMessage.SetFrom(sendgridMail.NewEmail(from.Name, from.Address))
@@ -82,6 +82,12 @@ func SendIndividualMail(to []server.EmailRecipient, from server.EmailSender, cc
 		sendMessage.AddCategories(tags...)
 	}
 
+	if len(customArgs) > 0 {
+		for key, value := range customArgs {
+			sendMessage.SetCustomArg(key, value)
+		}
+	}
+
 	return client.Send(sendMessage)
 }
 

internal/mail/mail_test.go

@@ -39,7 +39,7 @@ func TestSendMail(t *testing.T) {
 		return m.Headers["X-Test-Header"] == headers["X-Test-Header"]
 	})
 	client.On("Send", headersMatcher).Return(nil, nil)
-	mail.SendIndividualMail(toList, from, cc, bcc, headers, message, &client, []string{})
+	mail.SendIndividualMail(toList, from, cc, bcc, headers, message, &client, []string{}, map[string]string{})
 	client.AssertNumberOfCalls(t, "Send", 1)
 }
 

internal/service/api_email_service.go

@@ -43,7 +43,7 @@ func (s *EmailApiService) SendEmail(ctx context.Context, sendMailRequest server.
 
 	client := sendgrid.NewSendClient(s.config.SendgridAPIKey)
 
-	response, err := mail.SendIndividualMail(sendMailRequest.ToAddresses, sendMailRequest.FromAddress, sendMailRequest.CcAddresses, sendMailRequest.BccAddresses, sendMailRequest.Headers, sendMailRequest.Message, client, sendMailRequest.Tags)
+	response, err := mail.SendIndividualMail(sendMailRequest.ToAddresses, sendMailRequest.FromAddress, sendMailRequest.CcAddresses, sendMailRequest.BccAddresses, sendMailRequest.Headers, sendMailRequest.Message, client, sendMailRequest.Tags, sendMailRequest.CustomArgs)
 
 	if err != nil {
 		zap.S().Errorf("Error sending mail: %v", response)