Lazy loading of service descriptions (#11479)

* Lazy loading of service descriptions

* Fix tests

* Load YAML in executor

* Return a copy of available services to allow mutations

* Remove lint

* Add zha/services.yaml

* Only cache descriptions for known services

* Remove lint

* Remove description loading during service registration

* Remove description parameter from async_register

* Test async_get_all_descriptions

* Remove lint

* Fix typos from multi-edit

* Remove unused arguments

* Remove unused import os

* Remove unused import os, part 2

* Remove unneeded coroutine decorator

* Only use executor for loading files

* Cleanups suggested in review

* Increase test coverage

* Fix races in existing tests

homeassistant/components/system_log/__init__.py

@@ -4,7 +4,6 @@ Support for system log.
 For more details about this platform, please refer to the documentation at
 https://home-assistant.io/components/system_log/
 """
-import os
 import re
 import asyncio
 import logging
@@ -15,7 +14,6 @@ from collections import deque
 import voluptuous as vol
 
 from homeassistant import __path__ as HOMEASSISTANT_PATH
-from homeassistant.config import load_yaml_config_file
 import homeassistant.helpers.config_validation as cv
 from homeassistant.components.http import HomeAssistantView
 
@@ -84,13 +82,8 @@ def async_setup(hass, config):
         # Only one service so far
         handler.records.clear()
 
-    descriptions = yield from hass.async_add_job(
-        load_yaml_config_file, os.path.join(
-            os.path.dirname(__file__), 'services.yaml'))
-
     hass.services.async_register(
         DOMAIN, SERVICE_CLEAR, async_service_handler,
-        descriptions[DOMAIN].get(SERVICE_CLEAR),
         schema=SERVICE_CLEAR_SCHEMA)
 
     return True