Add homekit_controller tests (#20457)

* Add a test for a homekit_controller switch

* Add a test for a homekit_controller lightbulb

* Add a test for homekit_controller thermostat

* Changes from review

* Patch utcnow to known time in HK tests

* Neater fixture use per review

tests/components/homekit_controller/test_light.py

@@ -0,0 +1,46 @@
+"""Basic checks for HomeKitSwitch."""
+from tests.components.homekit_controller.common import (
+    setup_test_component)
+
+
+async def test_switch_change_light_state(hass, utcnow):
+    """Test that we can turn a HomeKit light on and off again."""
+    from homekit.model.services import BHSLightBulbService
+
+    helper = await setup_test_component(hass, [BHSLightBulbService()])
+
+    await hass.services.async_call('light', 'turn_on', {
+        'entity_id': 'light.testdevice',
+        'brightness': 255,
+        'hs_color': [4, 5],
+    }, blocking=True)
+    assert helper.characteristics[('lightbulb', 'on')].value == 1
+    assert helper.characteristics[('lightbulb', 'brightness')].value == 100
+    assert helper.characteristics[('lightbulb', 'hue')].value == 4
+    assert helper.characteristics[('lightbulb', 'saturation')].value == 5
+
+    await hass.services.async_call('light', 'turn_off', {
+        'entity_id': 'light.testdevice',
+    }, blocking=True)
+    assert helper.characteristics[('lightbulb', 'on')].value == 0
+
+
+async def test_switch_read_light_state(hass, utcnow):
+    """Test that we can read the state of a HomeKit light accessory."""
+    from homekit.model.services import BHSLightBulbService
+
+    helper = await setup_test_component(hass, [BHSLightBulbService()])
+
+    # Initial state is that the light is off
+    state = await helper.poll_and_get_state()
+    assert state.state == 'off'
+
+    # Simulate that someone switched on the device in the real world not via HA
+    helper.characteristics[('lightbulb', 'on')].set_value(True)
+    state = await helper.poll_and_get_state()
+    assert state.state == 'on'
+
+    # Simulate that device switched off in the real world not via HA
+    helper.characteristics[('lightbulb', 'on')].set_value(False)
+    state = await helper.poll_and_get_state()
+    assert state.state == 'off'