Fix clock skew calculations (#158)
Previously, the clock skew adjusted in the wrong direction. It would cause us to consider credentials whose expiration time had already pass according to the system clock to still be sent to the server. This is the opposite of what we wanted to happen. This fixes it so that we report that credentials are expired slightly before the system clock thinks they've expired.
diff --git a/tests/test_iam.py b/tests/test_iam.py
index f776788..97fa907 100644
--- a/tests/test_iam.py
+++ b/tests/test_iam.py
@@ -20,6 +20,7 @@
import pytest
from six.moves import http_client
+from google.auth import _helpers
from google.auth import exceptions
from google.auth import iam
from google.auth import transport
@@ -42,7 +43,7 @@
super(CredentialsImpl, self).__init__()
self.token = 'token'
# Force refresh
- self.expiry = datetime.datetime.min
+ self.expiry = datetime.datetime.min + _helpers.CLOCK_SKEW
def refresh(self, request):
pass