feat: add headers support to sendgrid mail

.github/workflows/build-and-test.yml

@@ -27,7 +27,7 @@ jobs:
 
     - name: Generate code
       run: |
-        docker run --rm -v ${GITHUB_WORKSPACE}:/local openapitools/openapi-generator-cli generate -i /local/api/notification-service.yaml -g go-server -o /local/ -p sourceFolder=internal/server -p packageName=server --git-user-id=commitdev --git-repo-id=zero-notification-service
+        docker run --rm -v ${GITHUB_WORKSPACE}:/local openapitools/openapi-generator:cli-5.3.x generate -i /local/api/notification-service.yaml -g go-server -o /local/ -p sourceFolder=internal/server -p packageName=server --git-user-id=commitdev --git-repo-id=zero-notification-service
         sudo chmod -R a+rw ${GITHUB_WORKSPACE}
         go get golang.org/x/tools/cmd/goimports
         goimports -w ${GITHUB_WORKSPACE}/internal/server/

.gitignore

@@ -1,3 +1,4 @@
+.env
 .envrc
 zero-notification-service
 .history/

api/notification-service.yaml

@@ -262,6 +262,8 @@ components:
           $ref: '#/components/schemas/EmailSender'
         message:
           $ref: '#/components/schemas/MailMessage'
+        headers:
+          $ref: '#/components/schemas/MailHeaders'
 
     SendBulkMailRequest:
       type: object
@@ -285,6 +287,8 @@ components:
           $ref: '#/components/schemas/EmailSender'
         message:
           $ref: '#/components/schemas/MailMessage'
+        headers:
+          $ref: '#/components/schemas/MailHeaders'
 
     MailMessage:
       type: object
@@ -305,6 +309,11 @@ components:
           description: Schedule these mesages to go out at the time specified by this UNIX timestamp
           format: int64
 
+    MailHeaders:
+      type: object
+      additionalProperties:
+        type: string
+
     SendSMSRequest:
       type: object
       required:

internal/mail/mail.go

@@ -22,14 +22,14 @@ type Client interface {
 
 // SendBulkMail sends a batch of email messages to all the specified recipients
 // All the calls to send mail happen in parallel, with their responses returned on the provided channel
-func SendBulkMail(toList []server.EmailRecipient, from server.EmailSender, cc []server.EmailRecipient, bcc []server.EmailRecipient, message server.MailMessage, client Client, responseChannel chan BulkSendAttempt) {
+func SendBulkMail(toList []server.EmailRecipient, from server.EmailSender, cc []server.EmailRecipient, bcc []server.EmailRecipient, headers map[string]string, message server.MailMessage, client Client, responseChannel chan BulkSendAttempt) {
 	wg := sync.WaitGroup{}
 	wg.Add(len(toList))
 
 	// Create goroutines for each send
 	for _, to := range toList {
 		go func(to server.EmailRecipient) {
-			response, err := SendIndividualMail([]server.EmailRecipient{to}, from, cc, bcc, message, client)
+			response, err := SendIndividualMail([]server.EmailRecipient{to}, from, cc, bcc, headers, message, client)
 			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, message server.MailMessage, client Client) (*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) (*rest.Response, error) {
 	sendMessage := sendgridMail.NewV3Mail()
 
 	sendMessage.SetFrom(sendgridMail.NewEmail(from.Name, from.Address))
@@ -72,6 +72,12 @@ func SendIndividualMail(to []server.EmailRecipient, from server.EmailSender, cc
 	}
 	sendMessage.AddPersonalizations(personalization)
 
+	if len(headers) > 0 {
+		for key, value := range headers {
+			sendMessage.SetHeader(key, value)
+		}
+	}
+
 	return client.Send(sendMessage)
 }
 

internal/mail/mail_test.go

@@ -20,22 +20,42 @@ type FakeClient struct {
 
 // Mock the Send function
 func (cl *FakeClient) Send(email *sendgridMail.SGMailV3) (*rest.Response, error) {
-	cl.Called()
+	cl.Called(email)
 	return nil, nil
 }
 
+func TestSendMail(t *testing.T) {
+	toList := createRandomRecipients(1, 1)
+	cc := make([]server.EmailRecipient, 0)
+	bcc := make([]server.EmailRecipient, 0)
+	from := server.EmailSender{Name: "Test User", Address: "address@domain.com"}
+	headers := map[string]string{
+		"X-Test-Header": "Test Header Value",
+	}
+	message := server.MailMessage{Subject: "Subject", Body: "Body"}
+	client := FakeClient{}
+
+	headersMatcher := mock.MatchedBy(func(m *sendgridMail.SGMailV3) bool {
+		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)
+	client.AssertNumberOfCalls(t, "Send", 1)
+}
+
 func TestSendBulkMail(t *testing.T) {
 	toList := createRandomRecipients(2, 5)
 	cc := make([]server.EmailRecipient, 0)
 	bcc := make([]server.EmailRecipient, 0)
 	from := server.EmailSender{Name: "Test User", Address: "address@domain.com"}
+	headers := make(map[string]string)
 	message := server.MailMessage{Subject: "Subject", Body: "Body"}
 	client := FakeClient{}
 
-	client.On("Send").Return(nil, nil)
+	client.On("Send", mock.Anything).Return(nil, nil)
 
 	responseChannel := make(chan mail.BulkSendAttempt)
-	mail.SendBulkMail(toList, from, cc, bcc, message, &client, responseChannel)
+	mail.SendBulkMail(toList, from, cc, bcc, headers, message, &client, responseChannel)
 
 	// Range over the channel until empty
 	returnedCount := 0

internal/service/api_email_service.go

@@ -42,7 +42,8 @@ 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.Message, client)
+
+	response, err := mail.SendIndividualMail(sendMailRequest.ToAddresses, sendMailRequest.FromAddress, sendMailRequest.CcAddresses, sendMailRequest.BccAddresses, sendMailRequest.Headers, sendMailRequest.Message, client)
 
 	if err != nil {
 		zap.S().Errorf("Error sending mail: %v", response)
@@ -79,7 +80,7 @@ func (s *EmailApiService) SendBulk(ctx context.Context, sendBulkMailRequest serv
 
 	responseChannel := make(chan mail.BulkSendAttempt)
 
-	mail.SendBulkMail(sendBulkMailRequest.ToAddresses, sendBulkMailRequest.FromAddress, sendBulkMailRequest.CcAddresses, sendBulkMailRequest.BccAddresses, sendBulkMailRequest.Message, client, responseChannel)
+	mail.SendBulkMail(sendBulkMailRequest.ToAddresses, sendBulkMailRequest.FromAddress, sendBulkMailRequest.CcAddresses, sendBulkMailRequest.BccAddresses, sendBulkMailRequest.Headers, sendBulkMailRequest.Message, client, responseChannel)
 
 	var successful []server.SendBulkMailResponseSuccessful
 	var failed []server.SendBulkMailResponseFailed