update docstring and unit tests

Author: nbayati

packages/google-auth/google/auth/transport/_mtls_helper.py

@@ -441,7 +441,7 @@ def _get_cert_config_path(certificate_config_path=None, include_context_aware=Tr
     certificate_config_path = path.expanduser(certificate_config_path)
     if not path.exists(certificate_config_path):
         if is_explicit:
-            _LOGGER.warning(
+            _LOGGER.debug(
                 "Certificate configuration file at %s does not exist",
                 certificate_config_path,
             )
@@ -729,7 +729,8 @@ def check_use_client_cert():
     will default to False.
     If GOOGLE_API_USE_CLIENT_CERTIFICATE is unset, the value will be inferred
     as True (auto-enabled) if a workload config file exists (pointed at by
-    GOOGLE_API_CERTIFICATE_CONFIG or CLOUDSDK_CONTEXT_AWARE_CERTIFICATE_CONFIG_FILE_PATH)
+    GOOGLE_API_CERTIFICATE_CONFIG or CLOUDSDK_CONTEXT_AWARE_CERTIFICATE_CONFIG_FILE_PATH,
+    or the default path like ~/.config/gcloud/certificate_config.json)
     containing a "workload" section.
     Otherwise, it returns False.
 

packages/google-auth/tests/transport/test_grpc.py

@@ -611,19 +611,14 @@ def test_get_client_ssl_credentials_transient_error_retry(
             certificate_chain=b"cert", private_key=b"key"
         )
 
-    @mock.patch(
-        "google.auth.transport.mtls.has_default_client_cert_source", autospec=True
-    )
     def test_get_client_ssl_credentials_auto_enablement(
         self,
-        mock_has_default_client_cert_source,
         mock_check_config_path,
         mock_load_json_file,
         mock_get_client_ssl_credentials,
         mock_ssl_channel_credentials,
     ):
         fake_config_content = '{"version": 1, "cert_configs": {"workload": {"cert_path": "/tmp/mock_cert.pem", "key_path": "/tmp/mock_key.pem"}}}'
-        mock_has_default_client_cert_source.return_value = True
         mock_get_client_ssl_credentials.return_value = (
             True,
             PUBLIC_CERT_BYTES,

packages/google-auth/tests/transport/test_mtls.py

@@ -49,7 +49,6 @@ def side_effect(path):
     assert result is True
     mock_get_cert.assert_called_once_with(include_context_aware=True)
     mock_check.assert_any_call(_mtls_helper.CONTEXT_AWARE_METADATA_PATH)
-    assert side_effect("non-matching-path") is None
 
 
 @mock.patch("google.auth.transport._mtls_helper._check_config_path")