fix: Create a check for billing started at in API usage task helper

api/organisations/task_helpers.py

@@ -106,6 +106,14 @@ def handle_api_usage_notification_for_organisation(organisation: Organisation) -
         subscription_cache = organisation.subscription_information_cache
         billing_starts_at = subscription_cache.current_billing_term_starts_at
 
+        if billing_starts_at is None:
+            # Since the calling code is a list of many organisations
+            # log the error and return without raising an exception.
+            logger.error(
+                f"Paid organisation {organisation.id} is missing billing_starts_at datetime"
+            )
+            return
+
         # Truncate to the closest active month to get start of current period.
         month_delta = relativedelta(now, billing_starts_at).months
         period_starts_at = relativedelta(months=month_delta) + billing_starts_at

api/tests/unit/organisations/test_unit_organisations_tasks.py

@@ -33,6 +33,9 @@
     SCALE_UP,
 )
 from organisations.subscriptions.xero.metadata import XeroSubscriptionMetadata
+from organisations.task_helpers import (
+    handle_api_usage_notification_for_organisation,
+)
 from organisations.tasks import (
     ALERT_EMAIL_MESSAGE,
     ALERT_EMAIL_SUBJECT,
@@ -244,6 +247,39 @@ def test_send_org_subscription_cancelled_alert(db: None, mocker: MockerFixture)
     )
 
 
+def test_handle_api_usage_notification_for_organisation_when_billing_starts_at_is_none(
+    organisation: Organisation,
+    inspecting_handler: logging.Handler,
+    mocker: MockerFixture,
+) -> None:
+    # Given
+    api_usage_mock = mocker.patch("organisations.task_helpers.get_current_api_usage")
+    organisation.subscription.plan = SCALE_UP
+    organisation.subscription.subscription_id = "fancy_id"
+    organisation.subscription.save()
+    OrganisationSubscriptionInformationCache.objects.create(
+        organisation=organisation,
+        allowed_seats=10,
+        allowed_projects=3,
+        allowed_30d_api_calls=100,
+        chargebee_email="[email protected]",
+        current_billing_term_starts_at=None,
+        current_billing_term_ends_at=None,
+    )
+    from organisations.task_helpers import logger
+
+    logger.addHandler(inspecting_handler)
+
+    # When
+    handle_api_usage_notification_for_organisation(organisation)
+
+    # Then
+    api_usage_mock.assert_not_called()
+    assert inspecting_handler.messages == [
+        f"Paid organisation {organisation.id} is missing billing_starts_at datetime"
+    ]
+
+
 @pytest.mark.freeze_time("2023-01-19T09:09:47.325132+00:00")
 def test_handle_api_usage_notifications_when_feature_flag_is_off(
     mocker: MockerFixture,