Don’t ask for data retention unless channel is known

If the user is looking at the notifications page for all message types
(which is what we show ‘caseworkers’) then it doesn’t make sense to ask
the API for the data retention period for that message type (because
it will be `None`). Doing so causes the API to return a `404`, which
then causes the admin app to return `404`.

Passing through `None` as the value of limit days will just cause the
API to return everything in the `notifications` table, which is fine
for us.

app/main/views/jobs.py

@@ -216,10 +216,12 @@ def get_notifications(service_id, message_type, status_override=None):
         abort(404)
     filter_args = parse_filter_args(request.args)
     filter_args['status'] = set_status_filters(filter_args)
+    service_data_retention_days = None
 
-    service_data_retention_days = service_api_client.get_service_data_retention_by_notification_type(
-        service_id, message_type
-    ).get('days_of_retention', current_app.config['ACTIVITY_STATS_LIMIT_DAYS'])
+    if message_type is not None:
+        service_data_retention_days = service_api_client.get_service_data_retention_by_notification_type(
+            service_id, message_type
+        ).get('days_of_retention', current_app.config['ACTIVITY_STATS_LIMIT_DAYS'])
 
     if request.path.endswith('csv') and current_user.has_permissions('view_activity'):
         return Response(

tests/app/main/views/test_activity.py

@@ -21,10 +21,28 @@ from tests.conftest import (
 
 
 @pytest.mark.parametrize(
-    "user,extra_args,expected_update_endpoint,page_title", [
-        (active_user_view_permissions, {'message_type': 'email'}, '/email.json', 'Emails'),
-        (active_user_view_permissions, {'message_type': 'sms'}, '/sms.json', 'Text messages'),
-        (active_caseworking_user, {}, '.json', 'Sent messages'),
+    "user,extra_args,expected_update_endpoint,expected_limit_days,page_title", [
+        (
+            active_user_view_permissions,
+            {'message_type': 'email'},
+            '/email.json',
+            7,
+            'Emails',
+        ),
+        (
+            active_user_view_permissions,
+            {'message_type': 'sms'},
+            '/sms.json',
+            7,
+            'Text messages',
+        ),
+        (
+            active_caseworking_user,
+            {},
+            '.json',
+            None,
+            'Sent messages',
+        ),
     ]
 )
 @pytest.mark.parametrize(
@@ -76,6 +94,7 @@ def test_can_show_notifications(
     user,
     extra_args,
     expected_update_endpoint,
+    expected_limit_days,
     page_title,
     status_argument,
     expected_api_call,
@@ -131,7 +150,7 @@ def test_can_show_notifications(
     assert 'to' not in query_dict
 
     mock_get_notifications.assert_called_with(
-        limit_days=7,
+        limit_days=expected_limit_days,
         page=expected_page_argument,
         service_id=service_one['id'],
         status=expected_api_call,
@@ -149,6 +168,20 @@ def test_can_show_notifications(
     assert json_content.keys() == {'counts', 'notifications', 'service_data_retention_days'}
 
 
+def test_can_show_notifications_if_data_retention_not_available(
+    client_request,
+    mock_get_notifications,
+    mock_get_service_statistics,
+    mock_has_no_jobs,
+):
+    page = client_request.get(
+        'main.view_notifications',
+        service_id=SERVICE_ONE_ID,
+        status='sending,delivered,failed',
+    )
+    assert page.h1.text.strip() == 'Messages'
+
+
 @pytest.mark.parametrize('user, query_parameters, expected_download_link', [
     (
         active_user_with_permissions,