Add support for attribute caching to the event platform (#106330)

homeassistant/components/event/__init__.py

@@ -5,7 +5,7 @@ from dataclasses import asdict, dataclass
 from datetime import datetime, timedelta
 from enum import StrEnum
 import logging
-from typing import Any, Self, final
+from typing import TYPE_CHECKING, Any, Self, final
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import HomeAssistant
@@ -21,6 +21,12 @@ from homeassistant.util import dt as dt_util
 
 from .const import ATTR_EVENT_TYPE, ATTR_EVENT_TYPES, DOMAIN
 
+if TYPE_CHECKING:
+    from functools import cached_property
+else:
+    from homeassistant.backports.functools import cached_property
+
+
 SCAN_INTERVAL = timedelta(seconds=30)
 
 ENTITY_ID_FORMAT = DOMAIN + ".{}"
@@ -101,7 +107,13 @@ class EventExtraStoredData(ExtraStoredData):
             return None
 
 
-class EventEntity(RestoreEntity):
+CACHED_PROPERTIES_WITH_ATTR_ = {
+    "device_class",
+    "event_types",
+}
+
+
+class EventEntity(RestoreEntity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
     """Representation of an Event entity."""
 
     _entity_component_unrecorded_attributes = frozenset({ATTR_EVENT_TYPES})
@@ -115,7 +127,7 @@ class EventEntity(RestoreEntity):
     __last_event_type: str | None = None
     __last_event_attributes: dict[str, Any] | None = None
 
-    @property
+    @cached_property
     def device_class(self) -> EventDeviceClass | None:
         """Return the class of this entity."""
         if hasattr(self, "_attr_device_class"):
@@ -124,7 +136,7 @@ class EventEntity(RestoreEntity):
             return self.entity_description.device_class
         return None
 
-    @property
+    @cached_property
     def event_types(self) -> list[str]:
         """Return a list of possible events."""
         if hasattr(self, "_attr_event_types"):

tests/components/event/test_init.py

@@ -56,6 +56,9 @@ async def test_event() -> None:
         event_types=["short_press", "long_press"],
         device_class=EventDeviceClass.DOORBELL,
     )
+    # Delete the cache since we changed the entity description
+    # at run time
+    del event.device_class
     assert event.event_types == ["short_press", "long_press"]
     assert event.device_class == EventDeviceClass.DOORBELL