For the post_sms_response and post_email_response the reference property is always present but the value can be null.

Added a test for an empty reference.
Remove datetime format on the created_at attribute of a notification, it is not needed.

app/notifications/process_notifications.py

@@ -57,7 +57,7 @@ def persist_notification(template_id,
         notification_type=notification_type,
         api_key_id=api_key_id,
         key_type=key_type,
-        created_at=created_at or datetime.utcnow().strftime(DATETIME_FORMAT),
+        created_at=created_at or datetime.utcnow(),
         job_id=job_id,
         job_row_number=job_row_number,
         client_reference=reference

app/v2/notifications/notification_schemas.py

@@ -47,7 +47,7 @@ post_sms_response = {
     "title": "response v2/notifications/sms",
     "properties": {
         "id": uuid,
-        "reference": {"type": "string"},
+        "reference": {"type": ["string", "null"]},
         "content": sms_content,
         "uri": {"type": "string"},
         "template": template
@@ -90,7 +90,7 @@ post_email_response = {
     "title": "response v2/notifications/email",
     "properties": {
         "id": uuid,
-        "reference": {"type": "string"},
+        "reference": {"type": ["string", "null"]},
         "content": email_content,
         "uri": {"type": "string"},
         "template": template

app/v2/notifications/post_notifications.py

@@ -38,7 +38,7 @@ def post_sms_notification():
                                         notification_type=SMS_TYPE,
                                         api_key_id=api_user.id,
                                         key_type=api_user.key_type,
-                                        reference=form['reference'])
+                                        reference=form.get('reference'))
     send_notification_to_queue(notification, service.research_mode)
 
     resp = create_post_sms_response_from_notification(notification,
@@ -65,7 +65,7 @@ def post_email_notification():
                                         notification_type=EMAIL_TYPE,
                                         api_key_id=api_user.id,
                                         key_type=api_user.key_type,
-                                        reference=form['reference'])
+                                        reference=form.get('reference'))
 
     send_notification_to_queue(notification, service.research_mode)
 

tests/app/v2/notifications/test_post_notifications.py

@@ -6,15 +6,17 @@ from app.models import Notification
 from tests import create_authorization_header
 
 
-def test_post_sms_notification_returns_201(notify_api, sample_template, mocker):
+@pytest.mark.parametrize("reference", [None, "reference_from_client"])
+def test_post_sms_notification_returns_201(notify_api, sample_template, mocker, reference):
     with notify_api.test_request_context():
         with notify_api.test_client() as client:
             mocked = mocker.patch('app.celery.provider_tasks.deliver_sms.apply_async')
             data = {
                 'phone_number': '+447700900855',
-                'template_id': str(sample_template.id),
+                'template_id': str(sample_template.id)
-                'reference': 'reference_from_client'
             }
+            if reference:
+                data.update({"reference": reference})
             auth_header = create_authorization_header(service_id=sample_template.service_id)
 
             response = client.post(
@@ -27,8 +29,8 @@ def test_post_sms_notification_returns_201(notify_api, sample_template, mocker):
             notifications = Notification.query.all()
             assert len(notifications) == 1
             notification_id = notifications[0].id
-            assert resp_json['id'] is not None
+            assert resp_json['id'] == notification_id
-            assert resp_json['reference'] == 'reference_from_client'
+            assert resp_json['reference'] == reference
             assert resp_json['content']['body'] == sample_template.content
             assert resp_json['content']['from_number'] == sample_template.service.sms_sender
             assert 'v2/notifications/{}'.format(notification_id) in resp_json['uri']
@@ -105,13 +107,15 @@ def test_post_sms_notification_returns_400_and_for_schema_problems(notify_api, s
                                              }]
 
 
-def test_post_email_notification_returns_201(client, sample_email_template, mocker):
+@pytest.mark.parametrize("reference", [None, "reference_from_client"])
+def test_post_email_notification_returns_201(client, sample_email_template, mocker, reference):
     mocked = mocker.patch('app.celery.provider_tasks.deliver_email.apply_async')
     data = {
-        "reference": "reference from caller",
         "email_address": sample_email_template.service.users[0].email_address,
         "template_id": sample_email_template.id,
     }
+    if reference:
+        data.update({"reference": reference})
     auth_header = create_authorization_header(service_id=sample_email_template.service_id)
     response = client.post(
         path="v2/notifications/email",
@@ -121,7 +125,7 @@ def test_post_email_notification_returns_201(client, sample_email_template, mock
     resp_json = json.loads(response.get_data(as_text=True))
     notification = Notification.query.first()
     assert resp_json['id'] == str(notification.id)
-    assert resp_json['reference'] == "reference from caller"
+    assert resp_json['reference'] == reference
     assert notification.reference is None
     assert resp_json['content']['body'] == sample_email_template.content
     assert resp_json['content']['subject'] == sample_email_template.subject