Add system tests; address review comments; skip tests when grpc isn't…

… available.

google/auth/transport/grpc.py

@@ -14,6 +14,8 @@
 
 """Authorization support for gRPC."""
 
+from __future__ import absolute_import
+
 import grpc
 
 
@@ -101,20 +103,16 @@ def secure_authorized_channel(
         grpc.Channel: The created gRPC channel.
     """
     # Create the metadata plugin for inserting the authorization header.
-    google_auth_credentials_metadata_plugin = AuthMetadataPlugin(
-        credentials, request)
+    metadata_plugin = AuthMetadataPlugin(credentials, request)
 
     # Create a set of grpc.CallCredentials using the metadata plugin.
-    google_auth_credentials = grpc.metadata_call_credentials(
-        google_auth_credentials_metadata_plugin)
+    google_auth_credentials = grpc.metadata_call_credentials(metadata_plugin)
 
-    if not ssl_credentials:
+    if ssl_credentials is None:
         ssl_credentials = grpc.ssl_channel_credentials()
 
     # Combine the ssl credentials and the authorization credentials.
     composite_credentials = grpc.composite_channel_credentials(
         ssl_credentials, google_auth_credentials)
 
-    channel = grpc.secure_channel(target, composite_credentials)
-
-    return channel
+    return grpc.secure_channel(target, composite_credentials)

pylintrc

@@ -137,12 +137,6 @@ method-rgx=[a-z_][a-z0-9_]{2,40}$
 # especially those that implemented wordy RFCs.
 function-rgx=[a-z_][a-z0-9_]{2,40}$
 
-# Regular expression matching correct variable names
-# DEFAULT:  variable-rgx=[a-z_][a-z0-9_]{2,30}$
-# RATIONALE:  Prefer longer, more specific variable names to avoid ambiguity. 
-# especially for methods that implement wordy rfcs or use wordy libraries.
-variable-rgx=[a-z_][a-z0-9_]{2,40}$
-
 [TYPECHECK]
 # List of module names for which member attributes should not be checked
 # (useful for modules/projects where namespaces are manipulated during runtime

pylintrc.tests

@@ -126,7 +126,7 @@ reports=no
 # DEFAULT:  good-names=i,j,k,ex,Run,_
 # RATIONALE:  'fh' is a well-known file handle variable name.
 good-names = i, j, k, ex, Run, _,
-             fh
+             fh, pytestmark
 
 # Regular expression matching correct method names
 # DEFAULT:  method-rgx=[a-z_][a-z0-9_]{2,30}$

system_tests/nox.py

@@ -248,3 +248,9 @@ def session_app_engine(session):
     session.env['TEST_APP_URL'] = application_url
     session.chdir(HERE)
     session.run('pytest', 'test_app_engine.py')
+
+
+def session_grpc(session):
+    session.virtualenv = False
+    session.env[EXPLICIT_CREDENTIALS_ENV] = SERVICE_ACCOUNT_FILE
+    session.run('pytest', 'test_grpc.py')

system_tests/test_grpc.py

@@ -0,0 +1,40 @@
+# Copyright 2016 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import google.auth
+import google.auth.credentials
+import google.auth.transport.grpc
+from google.cloud.gapic.pubsub.v1 import publisher_api
+
+
+def test_grpc_request(http_request):
+    credentials, project_id = google.auth.default()
+    credentials = google.auth.credentials.with_scopes_if_required(
+        credentials, ['https://www.googleapis.com/auth/pubsub'])
+
+    target = '{}:{}'.format(
+        publisher_api.PublisherApi.SERVICE_ADDRESS,
+        publisher_api.PublisherApi.DEFAULT_SERVICE_PORT)
+
+    channel = google.auth.transport.grpc.secure_authorized_channel(
+        credentials, target, http_request)
+
+    # Create a pub/sub client.
+    client = publisher_api.PublisherApi(channel=channel)
+
+    # list the topics and drain the iterator to test that an authorized API
+    # call works.
+    list_topics_iter = client.list_topics(
+        project='projects/{}'.format(project_id))
+    list(list_topics_iter)

tests/transport/test_grpc.py

@@ -14,8 +14,16 @@
 
 import mock
 
+import pytest
 
-import google.auth.transport.grpc
+try:
+    import google.auth.transport.grpc
+    HAS_GRPC = True
+except ImportError:  # pragma: NO COVER
+    HAS_GRPC = False
+
+
+pytestmark = pytest.mark.skipif(not HAS_GRPC, reason='gRPC is unavailable.')
 
 
 class MockCredentials(object):

tox.ini

@@ -11,7 +11,7 @@ deps =
   urllib3
   certifi
   requests
-  grpcio
+  grpcio; platform_python_implementation != 'PyPy'
 commands =
   py.test --cov=google.auth --cov=google.oauth2 --cov=tests {posargs:tests}
 
@@ -31,6 +31,7 @@ commands =
 deps =
   {[testenv]deps}
   nox-automation
+  gapic-google-pubsub-v1==0.11.1
 passenv =
   SKIP_APP_ENGINE_SYSTEM_TEST
   CLOUD_SDK_ROOT
@@ -43,6 +44,7 @@ commands =
 deps =
   {[testenv]deps}
   nox-automation
+  gapic-google-pubsub-v1==0.11.1
 passenv =
   SKIP_APP_ENGINE_SYSTEM_TEST
   CLOUD_SDK_ROOT