Define CoverEntity entity attributes as class variables (#51236)

* Define CoverEntity entity attributes as class variables

* Fix supported features

homeassistant/components/cover/__init__.py

@@ -1,4 +1,6 @@
 """Support for Cover devices."""
+from __future__ import annotations
+
 from datetime import timedelta
 import functools as ft
 import logging
@@ -167,22 +169,32 @@ async def async_unload_entry(hass, entry):
 class CoverEntity(Entity):
     """Base class for cover entities."""
 
+    _attr_current_cover_position: int | None = None
+    _attr_current_cover_tilt_position: int | None = None
+    _attr_is_closed: bool | None
+    _attr_is_closing: bool | None = None
+    _attr_is_opening: bool | None = None
+    _attr_state: None = None
+
     @property
-    def current_cover_position(self):
+    def current_cover_position(self) -> int | None:
         """Return current position of cover.
 
         None is unknown, 0 is closed, 100 is fully open.
         """
+        return self._attr_current_cover_position
 
     @property
-    def current_cover_tilt_position(self):
+    def current_cover_tilt_position(self) -> int | None:
         """Return current position of cover tilt.
 
         None is unknown, 0 is closed, 100 is fully open.
         """
+        return self._attr_current_cover_tilt_position
 
     @property
-    def state(self):
+    @final
+    def state(self) -> str | None:
         """Return the state of the cover."""
         if self.is_opening:
             return STATE_OPENING
@@ -213,8 +225,11 @@ class CoverEntity(Entity):
         return data
 
     @property
-    def supported_features(self):
+    def supported_features(self) -> int:
         """Flag supported features."""
+        if self._attr_supported_features is not None:
+            return self._attr_supported_features
+
         supported_features = SUPPORT_OPEN | SUPPORT_CLOSE | SUPPORT_STOP
 
         if self.current_cover_position is not None:
@@ -231,17 +246,19 @@ class CoverEntity(Entity):
         return supported_features
 
     @property
-    def is_opening(self):
+    def is_opening(self) -> bool | None:
         """Return if the cover is opening or not."""
+        return self._attr_is_opening
 
     @property
-    def is_closing(self):
+    def is_closing(self) -> bool | None:
         """Return if the cover is closing or not."""
+        return self._attr_is_closing
 
     @property
-    def is_closed(self):
+    def is_closed(self) -> bool | None:
         """Return if the cover is closed or not."""
-        raise NotImplementedError()
+        return self._attr_is_closed
 
     def open_cover(self, **kwargs: Any) -> None:
         """Open the cover."""

homeassistant/components/zwave_js/cover.py

@@ -147,7 +147,7 @@ class ZwaveMotorizedBarrier(ZWaveBaseEntity, CoverEntity):
         )
 
     @property
-    def supported_features(self) -> int | None:
+    def supported_features(self) -> int:
         """Flag supported features."""
         return SUPPORT_OPEN | SUPPORT_CLOSE