Simplify esphome (#22868)

* Add ESPHome climate support

* Adjust line length

* Update .coveragerc

* Update climate.py

* Simplify esphome integration

* Undo change

* Update cover.py

homeassistant/components/esphome/light.py

@@ -11,7 +11,7 @@ from homeassistant.config_entries import ConfigEntry
 from homeassistant.helpers.typing import HomeAssistantType
 import homeassistant.util.color as color_util
 
-from . import EsphomeEntity, platform_async_setup_entry
+from . import EsphomeEntity, platform_async_setup_entry, esphome_state_property
 
 if TYPE_CHECKING:
     # pylint: disable=unused-import
@@ -51,11 +51,9 @@ class EsphomeLight(EsphomeEntity, Light):
     def _state(self) -> Optional['LightState']:
         return super()._state
 
-    @property
+    @esphome_state_property
     def is_on(self) -> Optional[bool]:
         """Return true if the switch is on."""
-        if self._state is None:
-            return None
         return self._state.state
 
     async def async_turn_on(self, **kwargs) -> None:
@@ -88,42 +86,32 @@ class EsphomeLight(EsphomeEntity, Light):
             data['transition_length'] = kwargs[ATTR_TRANSITION]
         await self._client.light_command(**data)
 
-    @property
+    @esphome_state_property
     def brightness(self) -> Optional[int]:
         """Return the brightness of this light between 0..255."""
-        if self._state is None:
-            return None
         return round(self._state.brightness * 255)
 
-    @property
+    @esphome_state_property
     def hs_color(self) -> Optional[Tuple[float, float]]:
         """Return the hue and saturation color value [float, float]."""
-        if self._state is None:
-            return None
         return color_util.color_RGB_to_hs(
             self._state.red * 255,
             self._state.green * 255,
             self._state.blue * 255)
 
-    @property
+    @esphome_state_property
     def color_temp(self) -> Optional[float]:
         """Return the CT color value in mireds."""
-        if self._state is None:
-            return None
         return self._state.color_temperature
 
-    @property
+    @esphome_state_property
     def white_value(self) -> Optional[int]:
         """Return the white value of this light between 0..255."""
-        if self._state is None:
-            return None
         return round(self._state.white * 255)
 
-    @property
+    @esphome_state_property
     def effect(self) -> Optional[str]:
         """Return the current effect."""
-        if self._state is None:
-            return None
         return self._state.effect
 
     @property