test_statistics_device.py

# Copyright (C) 2022 ASTRON (Netherlands Institute for Radio Astronomy)
# SPDX-License-Identifier: Apache-2.0

from unittest import mock

from tango import server
from tango.test_context import DeviceTestContext

from test import base


class TestStatisticsDevice(base.TestCase):
    def setUp(self):
        super(TestStatisticsDevice, self).setUp()

    def test_python_bug(self):
        """Python is bugged and super() calls in ctypes fail

        This is the same type of issues that prevents combining metaclasses
        DeviceMeta and ABCMeta

        https://github.com/waveform80/picamera/issues/355
        https://bugs.python.org/issue29270
        """
        import ctypes as ct

        try:

            class TestSubclass(ct.c_uint32):
                def __repr__(self):
                    return super().__repr__()

        except Exception as e:
            self.assertIsInstance(e, TypeError)

    @mock.patch.object(server, "get_worker")
    def test_instance_statistics(self, m_worker):
        """Test that we can import and create a statistics device

        The import of Statistics fails when both ABCMeta and DeviceMeta are
        combined. Leave this test to prevent regressions when reattempting our
        combined metaclass.
        """

        from tangostationcontrol.devices.sdp.statistics import Statistics

        with DeviceTestContext(Statistics, process=True) as proxy:
            self.assertTrue(proxy.ping() > 0)