Added a test for when the reply to email id does not exist

tests/app/service/test_send_one_off_notification.py

@@ -4,7 +4,6 @@ from unittest.mock import Mock
 import pytest
 from notifications_utils.recipients import InvalidPhoneError
 
-import app
 from app.v2.errors import BadRequestError, TooManyRequestsError
 from app.config import QueueNames
 from app.service.send_notification import send_one_off_notification
@@ -204,3 +203,17 @@ def test_send_one_off_notification_should_add_email_reply_to_id_for_email(sample
     )
     mapping_row = NotificationEmailReplyTo.query.filter_by(notification_id=notification_id['id']).first()
     assert mapping_row.service_email_reply_to_id == reply_to_email.id
+
+
+def test_send_one_off_notification_should_throw_exception_if_reply_to_id_doesnot_exist(
+        sample_email_template, celery_mock
+):
+    data = {
+        'to': 'ok@ok.com',
+        'template_id': str(sample_email_template.id),
+        'sender_id': str(uuid.uuid4()),
+        'created_by': str(sample_email_template.service.created_by_id)
+    }
+
+    with pytest.raises(expected_exception=BadRequestError):
+        send_one_off_notification(service_id=sample_email_template.service.id, post_data=data)