Factoring out the parts of make_secure_stub() that create a channel.

core/google/cloud/_helpers.py

@@ -620,8 +620,8 @@ def __call__(self, unused_context, callback):
         callback(headers, None)
 
 
-def make_secure_stub(credentials, user_agent, stub_class, host):
-    """Makes a secure stub for an RPC service.
+def make_secure_channel(credentials, user_agent, host):
+    """Makes a secure channel for an RPC service.
 
     Uses / depends on gRPC.
 
@@ -630,16 +630,13 @@ def make_secure_stub(credentials, user_agent, stub_class, host):
                         access tokens.
 
     :type user_agent: str
-    :param user_agent: (Optional) The user agent to be used with API requests.
-
-    :type stub_class: type
-    :param stub_class: A gRPC stub type for a given service.
+    :param user_agent: The user agent to be used with API requests.
 
     :type host: str
     :param host: The host for the service.
 
-    :rtype: object, instance of ``stub_class``
-    :returns: The stub object used to make gRPC requests to a given API.
+    :rtype: :class:`grpc._channel.Channel`
+    :returns: gRPC secure channel with credentials attached.
     """
     # ssl_channel_credentials() loads root certificates from
     # `grpc/_adapter/credentials/roots.pem`.
@@ -653,8 +650,32 @@ def make_secure_stub(credentials, user_agent, stub_class, host):
     channel_args = (
         ('grpc.primary_user_agent', user_agent),
     )
-    channel = grpc.secure_channel(target, channel_creds,
-                                  options=channel_args)
+    return grpc.secure_channel(target, channel_creds,
+                               options=channel_args)
+
+
+def make_secure_stub(credentials, user_agent, stub_class, host):
+    """Makes a secure stub for an RPC service.
+
+    Uses / depends on gRPC.
+
+    :type credentials: :class:`oauth2client.client.OAuth2Credentials`
+    :param credentials: The OAuth2 Credentials to use for creating
+                        access tokens.
+
+    :type user_agent: str
+    :param user_agent: The user agent to be used with API requests.
+
+    :type stub_class: type
+    :param stub_class: A gRPC stub type for a given service.
+
+    :type host: str
+    :param host: The host for the service.
+
+    :rtype: object, instance of ``stub_class``
+    :returns: The stub object used to make gRPC requests to a given API.
+    """
+    channel = make_secure_channel(credentials, user_agent, host)
     return stub_class(channel)
 
 

core/unit_tests/test__helpers.py

@@ -917,20 +917,17 @@ def callback(*args):
         self.assertEqual(len(credentials._tokens), 1)
 
 
-class Test_make_secure_stub(unittest.TestCase):
+class Test_make_secure_channel(unittest.TestCase):
 
     def _callFUT(self, *args, **kwargs):
-        from google.cloud._helpers import make_secure_stub
-        return make_secure_stub(*args, **kwargs)
+        from google.cloud._helpers import make_secure_channel
+        return make_secure_channel(*args, **kwargs)
 
     def test_it(self):
         from six.moves import http_client
         from google.cloud._testing import _Monkey
         from google.cloud import _helpers as MUT
 
-        mock_result = object()
-        stub_inputs = []
-
         SSL_CREDS = object()
         METADATA_CREDS = object()
         COMPOSITE_CREDS = object()
@@ -961,11 +958,6 @@ def secure_channel(self, *args, **kwargs):
                 return CHANNEL
 
         grpc_mod = _GRPCModule()
-
-        def mock_stub_class(channel):
-            stub_inputs.append(channel)
-            return mock_result
-
         metadata_plugin = object()
         plugin_args = []
 
@@ -978,11 +970,9 @@ def mock_plugin(*args):
         user_agent = 'USER_AGENT'
         with _Monkey(MUT, grpc=grpc_mod,
                      MetadataPlugin=mock_plugin):
-            result = self._callFUT(credentials, user_agent,
-                                   mock_stub_class, host)
+            result = self._callFUT(credentials, user_agent, host)
 
-        self.assertIs(result, mock_result)
-        self.assertEqual(stub_inputs, [CHANNEL])
+        self.assertIs(result, CHANNEL)
         self.assertEqual(plugin_args, [(credentials,)])
         self.assertEqual(grpc_mod.ssl_channel_credentials_args, ())
         self.assertEqual(grpc_mod.metadata_call_credentials_args,
@@ -999,6 +989,42 @@ def mock_plugin(*args):
                          (secure_args, secure_kwargs))
 
 
+class Test_make_secure_stub(unittest.TestCase):
+
+    def _callFUT(self, *args, **kwargs):
+        from google.cloud._helpers import make_secure_stub
+        return make_secure_stub(*args, **kwargs)
+
+    def test_it(self):
+        from google.cloud._testing import _Monkey
+        from google.cloud import _helpers as MUT
+
+        result = object()
+        channel_obj = object()
+        channels = []
+        channel_args = []
+
+        def stub_class(channel):
+            channels.append(channel)
+            return result
+
+        def mock_channel(*args):
+            channel_args.append(args)
+            return channel_obj
+
+        credentials = object()
+        user_agent = 'you-sir-age-int'
+        host = 'localhost'
+        with _Monkey(MUT, make_secure_channel=mock_channel):
+            stub = self._callFUT(credentials, user_agent,
+                                 stub_class, host)
+
+        self.assertIs(stub, result)
+        self.assertEqual(channels, [channel_obj])
+        self.assertEqual(channel_args,
+                         [(credentials, user_agent, host)])
+
+
 class Test_make_insecure_stub(unittest.TestCase):
 
     def _callFUT(self, *args, **kwargs):