rename days_ago to midnight_n_days_ago

also add some more timezone boundary tests and minor code cleanup

app/dao/jobs_dao.py

@@ -10,7 +10,7 @@ from sqlalchemy import (
 )
 
 from app import db
-from app.utils import days_ago
+from app.utils import midnight_n_days_ago
 from app.models import (
     Job,
     JOB_STATUS_PENDING,
@@ -51,7 +51,7 @@ def dao_get_jobs_by_service_id(service_id, limit_days=None, page=1, page_size=50
         Job.original_file_name != current_app.config['ONE_OFF_MESSAGE_FILENAME'],
     ]
     if limit_days is not None:
-        query_filter.append(Job.created_at >= days_ago(limit_days))
+        query_filter.append(Job.created_at >= midnight_n_days_ago(limit_days))
     if statuses is not None and statuses != ['']:
         query_filter.append(
             Job.job_status.in_(statuses)

app/dao/notifications_dao.py

@@ -21,7 +21,7 @@ from sqlalchemy.sql import functions
 from notifications_utils.international_billing_rates import INTERNATIONAL_BILLING_RATES
 
 from app import db, create_uuid
-from app.utils import days_ago
+from app.utils import midnight_n_days_ago
 from app.errors import InvalidRequest
 from app.models import (
     Notification,
@@ -248,7 +248,7 @@ def get_notifications_for_service(
     filters = [Notification.service_id == service_id]
 
     if limit_days is not None:
-        filters.append(Notification.created_at >= days_ago(limit_days))
+        filters.append(Notification.created_at >= midnight_n_days_ago(limit_days))
 
     if older_than is not None:
         older_than_created_at = db.session.query(

app/template_statistics/rest.py

@@ -39,7 +39,7 @@ def get_template_statistics_for_service_by_day(service_id):
     if limit_days < 1 or limit_days > 7:
         raise InvalidRequest({'limit_days': ['limit_days must be between 1 and 7']}, status_code=400)
 
-    return jsonify(data=get_template_statistics_for_last_n_days(service_id, limit_days))
+    return jsonify(data=_get_template_statistics_for_last_n_days(service_id, limit_days))
 
 
 @template_statistics.route('/<template_id>')
@@ -58,7 +58,7 @@ def get_template_statistics_for_template_id(service_id, template_id):
     return jsonify(data=data)
 
 
-def get_template_statistics_for_last_n_days(service_id, limit_days):
+def _get_template_statistics_for_last_n_days(service_id, limit_days):
     template_stats_by_id = Counter()
 
     for day in last_n_days(limit_days):
@@ -77,6 +77,7 @@ def get_template_statistics_for_last_n_days(service_id, limit_days):
             # if there is data in db, but not in redis - lets put it in redis so we don't have to do
             # this calc again next time. If there isn't any data, we can't put it in redis.
             # Zero length hashes aren't a thing in redis. (There'll only be no data if the service has no templates)
+            # Nothing is stored if redis is down.
             if stats:
                 redis_store.set_hash_and_expire(
                     key,

app/utils.py

@@ -81,7 +81,7 @@ def cache_key_for_service_template_counter(service_id, limit_days=7):
 
 def cache_key_for_service_template_usage_per_day(service_id, datetime):
     """
-    You should probably pass a BST datetime into this function
+    You should pass a BST datetime into this function
     """
     return "service-{}-template-usage-{}".format(service_id, datetime.date().isoformat())
 
@@ -95,7 +95,7 @@ def get_public_notify_type_text(notify_type, plural=False):
     return '{}{}'.format(notify_type_text, 's' if plural else '')
 
 
-def days_ago(number_of_days):
+def midnight_n_days_ago(number_of_days):
     """
     Returns midnight a number of days ago. Takes care of daylight savings etc.
     """