The regex to validate uuids was not rejecting uuids with a space at the end.

Switched to using a isinstance check on the string.
Added an order by clause to dao_get_template_usage_stats_by_service, it was causing an itermitten failure in the tests.

app/dao/stats_template_usage_by_month_dao.py

@@ -1,5 +1,5 @@
 from notifications_utils.statsd_decorators import statsd
-from sqlalchemy import or_, and_
+from sqlalchemy import or_, and_, desc
 
 from app import db
 from app.dao.dao_utils import transactional
@@ -54,4 +54,6 @@ def dao_get_template_usage_stats_by_service(service_id, year):
                 StatsTemplateUsageByMonth.year == year + 1
             )
         )
+    ).order_by(
+        desc(StatsTemplateUsageByMonth.month)
     ).all()

app/schema_validation/__init__.py

@@ -1,5 +1,6 @@
 import json
 from datetime import datetime, timedelta
+from uuid import UUID
 
 from iso8601 import iso8601, ParseError
 from jsonschema import (Draft4Validator, ValidationError, FormatChecker)
@@ -10,6 +11,12 @@ from notifications_utils.recipients import (validate_phone_number, validate_emai
 def validate(json_to_validate, schema):
     format_checker = FormatChecker()
 
+    @format_checker.checks("validate_uuid", raises=Exception)
+    def validate_uuid(instance):
+        if isinstance(instance, str):
+            UUID(instance)
+        return True
+
     @format_checker.checks('phone_number', raises=InvalidPhoneError)
     def validate_schema_phone_number(instance):
         if isinstance(instance, str):

app/schema_validation/definitions.py

@@ -5,7 +5,7 @@ If the definition is specific to a version put it in a definition file in the ve
 
 uuid = {
     "type": "string",
-    "pattern": "^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}$",
+    "format": "validate_uuid",
     "validationMessage": "is not a valid UUID",
     "code": "1001",  # yet to be implemented
     "link": "link to our error documentation not yet implemented"