def test_transport_instance():
    # A client may be instantiated with a custom transport instance.
    transport = transports.TestingGrpcTransport(
        credentials=credentials.AnonymousCredentials(),
    )
    client = TestingClient(transport=transport)
    assert client._transport is transport
def test_credentials_transport_error():
    # It is an error to provide credentials and a transport instance.
    transport = transports.TestingGrpcTransport(
        credentials=credentials.AnonymousCredentials(), )
    with pytest.raises(ValueError):
        client = TestingClient(
            credentials=credentials.AnonymousCredentials(),
            transport=transport,
        )
def test_testing_grpc_transport_channel():
    channel = grpc.insecure_channel('http://localhost/')
    transport = transports.TestingGrpcTransport(channel=channel, )
    assert transport.grpc_channel is channel