Modify the dummy tests to be timezone-safe (#953)

The dummy tests were failing on my non-UTC development machine, because
the timestamps were generated with mktime(), which uses the locale
settings from the host. Changing this to use the timezone-aware `now`
sorted it.

Co-authored-by: Chris Rose <[email protected]>

Author: nijel

social_core/storage.py

@@ -2,7 +2,6 @@
 
 import base64
 import re
-import time
 import uuid
 import warnings
 from datetime import datetime, timedelta, timezone
@@ -71,9 +70,10 @@ def expiration_timedelta(self):
             now = datetime.now(timezone.utc)
 
             # Detect if expires is a timestamp
-            if expires > time.mktime(now.timetuple()):
+            if expires > now.timestamp():
                 # expires is a datetime, return the remaining difference
-                return datetime.fromtimestamp(expires, tz=timezone.utc) - now
+                expiry_time = datetime.fromtimestamp(expires, tz=timezone.utc)
+                return expiry_time - now
             else:
                 # expires is the time to live seconds since creation,
                 # check against auth_time if present, otherwise return

social_core/tests/backends/test_dummy.py

@@ -1,6 +1,5 @@
 import datetime
 import json
-import time
 
 from httpretty import HTTPretty
 
@@ -121,9 +120,7 @@ class ExpirationTimeTest(DummyOAuth2Test):
             "first_name": "Foo",
             "last_name": "Bar",
             "email": "[email protected]",
-            "expires": time.mktime(
-                (datetime.datetime.now(datetime.timezone.utc) + DELTA).timetuple()
-            ),
+            "expires": (datetime.datetime.now() + DELTA).timestamp(),
         }
     )