Add LogBook support to HomeKit (#17180)

tests/components/homekit/conftest.py

@@ -3,6 +3,9 @@ from unittest.mock import patch
 
 import pytest
 
+from homeassistant.components.homekit.const import EVENT_HOMEKIT_CHANGED
+from homeassistant.core import callback
+
 from pyhap.accessory_driver import AccessoryDriver
 
 
@@ -14,3 +17,13 @@ def hk_driver():
         patch('pyhap.accessory_driver.HAPServer'), \
             patch('pyhap.accessory_driver.AccessoryDriver.publish'):
         return AccessoryDriver(pincode=b'123-45-678', address='127.0.0.1')
+
+
+@pytest.fixture
+def events(hass):
+    """Yield caught homekit_changed events."""
+    events = []
+    hass.bus.async_listen(
+        EVENT_HOMEKIT_CHANGED,
+        callback(lambda e: events.append(e)))
+    yield events