camera_tests.py

import unittest

from camera import Controller, Sensor, Recorder


class CameraTests(unittest.TestCase):
    def test_asks_the_recorder_to_stop_recording_when_no_information_received_from_sensor(self):
        sensor = Sensor()  # mocks
        recorder = Recorder()  # mocks
        self.called = False

        def save_call():
            self.called = True

        sensor.is_detecting_movement = lambda: False
        recorder.stop_recording = save_call
        controller = Controller(sensor, recorder)

        controller.record_movement()

        self.assertTrue(self.called)