HomeKit Alarm Control Panel Code Exception Fix (#14025)

* Catch exception for KeyError
* Use get and added test

homeassistant/components/homekit/type_security_systems.py

@@ -30,7 +30,7 @@ class SecuritySystem(HomeAccessory):
     def __init__(self, *args, config):
         """Initialize a SecuritySystem accessory object."""
         super().__init__(*args, category=CATEGORY_ALARM_SYSTEM)
-        self._alarm_code = config[ATTR_CODE]
+        self._alarm_code = config.get(ATTR_CODE)
         self.flag_target_state = False
 
         serv_alarm = add_preload_service(self, SERV_SECURITY_SYSTEM)

tests/components/homekit/test_type_security_systems.py

@@ -109,8 +109,16 @@ class TestHomekitSecuritySystems(unittest.TestCase):
 
         acc = SecuritySystem(self.hass, 'SecuritySystem', acp,
                              2, config={ATTR_CODE: None})
-        acc.run()
-
+        # Set from HomeKit
+        acc.char_target_state.client_update_value(0)
+        self.hass.block_till_done()
+        self.assertEqual(
+            self.events[0].data[ATTR_SERVICE], 'alarm_arm_home')
+        self.assertNotIn(ATTR_CODE, self.events[0].data[ATTR_SERVICE_DATA])
+        self.assertEqual(acc.char_target_state.value, 0)
+
+        acc = SecuritySystem(self.hass, 'SecuritySystem', acp,
+                             2, config={})
         # Set from HomeKit
         acc.char_target_state.client_update_value(0)
         self.hass.block_till_done()