class TestVideoStreamDispatcher(object): SAMPLE_DEFAULT_IMAGE = object() SAMPLE_IMAGE = object() SAMPLE_FPS = 5 @mock.patch('services.video_streaming.stream_writers.InMemoryBufferedStreamWriter.InMemoryBufferedStreamWriter', autospec = False) @mock.patch('services.video_streaming.stream_readers.CameraStreamReader.CameraStreamReader', autospec = False) def setup(self, stream_reader_mock, stream_writer_mock): self._stream_reader_mock = stream_reader_mock self._stream_writer_mock = stream_writer_mock self._stream_reader_mock.read_next.side_effect = self._read_next_mock self._video_stream_dispatcher = VideoStreamDispatcher(self.SAMPLE_DEFAULT_IMAGE) self._video_stream_dispatcher.stream_reader = stream_reader_mock self._video_stream_dispatcher.add_stream_writer(stream_writer_mock) def _read_next_mock(self): time.sleep(1 / self.SAMPLE_FPS) return self.SAMPLE_IMAGE def test_when_dispatching_then_image_is_dispatched_to_stream_writer(self): self._dispatch() self._stream_writer_mock.write.assert_called_with(self.SAMPLE_IMAGE) def test_given_read_error_when_dispatching_then_last_image_is_dispatched_to_stream_writer(self): self._stream_reader_mock.read_next.side_effect = [self.SAMPLE_IMAGE, IOError] self._dispatch() self._stream_writer_mock.write.assert_called_with(self.SAMPLE_IMAGE) def test_given_read_error_and_no_last_image_when_dispatching_then_default_image_is_dispatched_to_stream_writer(self): self._stream_reader_mock.read_next.side_effect = IOError self._dispatch() self._stream_writer_mock.write.assert_called_with(self.SAMPLE_DEFAULT_IMAGE) def _dispatch(self): self._video_stream_dispatcher.start_dispatching_async() time.sleep(0.25) self._video_stream_dispatcher.stop_dispatching()