Add api_core package (#4210)

* Add api_core package

* Address review comments

1 files changed, 171 insertions, 0 deletions

diff --git a/tests/unit/test_grpc_helpers.py b/tests/unit/test_grpc_helpers.py
new file mode 100644
index 0000000..d5e0b3c
--- /dev/null
+++ b/tests/unit/test_grpc_helpers.py
@@ -0,0 +1,171 @@
+# Copyright 2017 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 grpc
+import mock
+import pytest
+
+from google.api_core import exceptions
+from google.api_core import grpc_helpers
+
+
+def test__patch_callable_name():
+    callable = mock.Mock(spec=['__class__'])
+    callable.__class__ = mock.Mock(spec=['__name__'])
+    callable.__class__.__name__ = 'TestCallable'
+
+    grpc_helpers._patch_callable_name(callable)
+
+    assert callable.__name__ == 'TestCallable'
+
+
+def test__patch_callable_name_no_op():
+    callable = mock.Mock(spec=['__name__'])
+    callable.__name__ = 'test_callable'
+
+    grpc_helpers._patch_callable_name(callable)
+
+    assert callable.__name__ == 'test_callable'
+
+
+class RpcErrorImpl(grpc.RpcError, grpc.Call):
+    def __init__(self, code):
+        super(RpcErrorImpl, self).__init__()
+        self._code = code
+
+    def code(self):
+        return self._code
+
+    def details(self):
+        return None
+
+
+def test_wrap_unary_errors():
+    grpc_error = RpcErrorImpl(grpc.StatusCode.INVALID_ARGUMENT)
+    callable_ = mock.Mock(spec=['__call__'], side_effect=grpc_error)
+
+    wrapped_callable = grpc_helpers._wrap_unary_errors(callable_)
+
+    with pytest.raises(exceptions.InvalidArgument) as exc_info:
+        wrapped_callable(1, 2, three='four')
+
+    callable_.assert_called_once_with(1, 2, three='four')
+    assert exc_info.value.response == grpc_error
+
+
+def test_wrap_stream_errors_invocation():
+    grpc_error = RpcErrorImpl(grpc.StatusCode.INVALID_ARGUMENT)
+    callable_ = mock.Mock(spec=['__call__'], side_effect=grpc_error)
+
+    wrapped_callable = grpc_helpers._wrap_stream_errors(callable_)
+
+    with pytest.raises(exceptions.InvalidArgument) as exc_info:
+        wrapped_callable(1, 2, three='four')
+
+    callable_.assert_called_once_with(1, 2, three='four')
+    assert exc_info.value.response == grpc_error
+
+
+class RpcResponseIteratorImpl(object):
+    def __init__(self, exception):
+        self._exception = exception
+
+    # Note: This matches grpc._channel._Rendezvous._next which is what is
+    # patched by _wrap_stream_errors.
+    def _next(self):
+        raise self._exception
+
+    def __next__(self):  # pragma: NO COVER
+        return self._next()
+
+    def next(self):  # pragma: NO COVER
+        return self._next()
+
+
+def test_wrap_stream_errors_iterator():
+    grpc_error = RpcErrorImpl(grpc.StatusCode.UNAVAILABLE)
+    response_iter = RpcResponseIteratorImpl(grpc_error)
+    callable_ = mock.Mock(spec=['__call__'], return_value=response_iter)
+
+    wrapped_callable = grpc_helpers._wrap_stream_errors(callable_)
+
+    got_iterator = wrapped_callable(1, 2, three='four')
+
+    with pytest.raises(exceptions.ServiceUnavailable) as exc_info:
+        next(got_iterator)
+
+    assert got_iterator == response_iter
+    callable_.assert_called_once_with(1, 2, three='four')
+    assert exc_info.value.response == grpc_error
+
+
+@mock.patch('google.api_core.grpc_helpers._wrap_unary_errors')
+def test_wrap_errors_non_streaming(wrap_unary_errors):
+    callable_ = mock.create_autospec(grpc.UnaryUnaryMultiCallable)
+
+    result = grpc_helpers.wrap_errors(callable_)
+
+    assert result == wrap_unary_errors.return_value
+    wrap_unary_errors.assert_called_once_with(callable_)
+
+
+@mock.patch('google.api_core.grpc_helpers._wrap_stream_errors')
+def test_wrap_errors_streaming(wrap_stream_errors):
+    callable_ = mock.create_autospec(grpc.UnaryStreamMultiCallable)
+
+    result = grpc_helpers.wrap_errors(callable_)
+
+    assert result == wrap_stream_errors.return_value
+    wrap_stream_errors.assert_called_once_with(callable_)
+
+
+@mock.patch(
+    'google.auth.default',
+    return_value=(mock.sentinel.credentials, mock.sentinel.projet))
+@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
+def test_create_channel_implicit(secure_authorized_channel, default):
+    target = 'example.com:443'
+
+    channel = grpc_helpers.create_channel(target)
+
+    assert channel is secure_authorized_channel.return_value
+    default.assert_called_once_with(scopes=None)
+    secure_authorized_channel.assert_called_once_with(
+        mock.sentinel.credentials, mock.ANY, target)
+
+
+@mock.patch(
+    'google.auth.default',
+    return_value=(mock.sentinel.credentials, mock.sentinel.projet))
+@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
+def test_create_channel_implicit_with_scopes(
+        secure_authorized_channel, default):
+    target = 'example.com:443'
+
+    channel = grpc_helpers.create_channel(target, scopes=['one', 'two'])
+
+    assert channel is secure_authorized_channel.return_value
+    default.assert_called_once_with(scopes=['one', 'two'])
+
+
+@mock.patch('google.auth.transport.grpc.secure_authorized_channel')
+def test_create_channel_explicit(secure_authorized_channel):
+    target = 'example.com:443'
+
+    channel = grpc_helpers.create_channel(
+        target, credentials=mock.sentinel.credentials)
+
+    assert channel is secure_authorized_channel.return_value
+    secure_authorized_channel.assert_called_once_with(
+        mock.sentinel.credentials, mock.ANY, target)