fix: migrate datetime.utcnow for python 3.12 (#1413)

google/auth/_helpers.py

@@ -92,7 +92,14 @@ def utcnow():
  Returns:
  datetime: The current time in UTC.
  """
- return datetime.datetime.utcnow()
+ # We used datetime.utcnow() before, since it's deprecated from python 3.12,
+ # we are using datetime.now(timezone.utc) now. "utcnow()" is offset-native
+ # (no timezone info), but "now()" is offset-aware (with timezone info).
+ # This will cause datetime comparison problem. For backward compatibility,
+ # we need to remove the timezone info.
+ now = datetime.datetime.now(datetime.timezone.utc)
+ now = now.replace(tzinfo=None)
+ return now
 
 
 def datetime_to_secs(value):

tests/test_credentials.py

@@ -55,17 +55,15 @@ def test_expired_and_valid():
  # Set the expiration to one second more than now plus the clock skew
  # accomodation. These credentials should be valid.
  credentials.expiry = (
- datetime.datetime.utcnow()
- + _helpers.REFRESH_THRESHOLD
- + datetime.timedelta(seconds=1)
+ _helpers.utcnow() + _helpers.REFRESH_THRESHOLD + datetime.timedelta(seconds=1)
  )
 
  assert credentials.valid
  assert not credentials.expired
 
  # Set the credentials expiration to now. Because of the clock skew
  # accomodation, these credentials should report as expired.
- credentials.expiry = datetime.datetime.utcnow()
+ credentials.expiry = _helpers.utcnow()
 
  assert not credentials.valid
  assert credentials.expired

tests_async/test_credentials_async.py

@@ -46,17 +46,15 @@ def test_expired_and_valid():
  # Set the expiration to one second more than now plus the clock skew
  # accomodation. These credentials should be valid.
  credentials.expiry = (
- datetime.datetime.utcnow()
- + _helpers.REFRESH_THRESHOLD
- + datetime.timedelta(seconds=1)
+ _helpers.utcnow() + _helpers.REFRESH_THRESHOLD + datetime.timedelta(seconds=1)
  )
 
  assert credentials.valid
  assert not credentials.expired
 
  # Set the credentials expiration to now. Because of the clock skew
  # accomodation, these credentials should report as expired.
- credentials.expiry = datetime.datetime.utcnow()
+ credentials.expiry = _helpers.utcnow()
 
  assert not credentials.valid
  assert credentials.expired