#225: Fix timezone-related issues found by merging master

- These issues were a result of writing new code that involved timezones before master got merged in, which had the original fixes for timezones on DB backend

datagateway_api/common/helpers.py

@@ -3,6 +3,7 @@
 import json
 import logging
 
+from dateutil.tz.tz import tzlocal
 from flask import request
 from flask_restful import reqparse
 from sqlalchemy.exc import IntegrityError
@@ -157,6 +158,10 @@ def map_distinct_attributes_to_results(distinct_attributes, query_result):
         split_attr_name = attr_name.split(".")
 
         if isinstance(data, datetime):
+            # Workaround for when this function is used on DB backend, where usually
+            # `_make_serializable()` would fix tzinfo
+            if data.tzinfo is None:
+                data = data.replace(tzinfo=tzlocal())
             data = DateHandler.datetime_object_to_str(data)
 
         # Attribute name is from the 'origin' entity (i.e. not a related entity)

test/icat/test_query.py

@@ -1,6 +1,5 @@
 from datetime import datetime
 
-from dateutil.tz import tzlocal
 from icat.entity import Entity
 import pytest
 

test/test_map_distinct_attrs.py

@@ -1,5 +1,6 @@
-from datetime import datetime, timezone
+from datetime import datetime
 
+from dateutil.tz import tzlocal
 import pytest
 
 from datagateway_api.common.helpers import map_distinct_attributes_to_results
@@ -25,7 +26,7 @@ class TestMapDistinctAttrs:
                         hour=1,
                         minute=1,
                         second=1,
-                        tzinfo=timezone.utc,
+                        tzinfo=tzlocal(),
                     ),
                 ),
                 {"startDate": "2020-01-04 01:01:01+00:00"},