Fix ESPHome event entity staying unavailable (#141650)

homeassistant/components/esphome/event.py

@@ -33,6 +33,16 @@ class EsphomeEvent(EsphomeEntity[EventInfo, Event], EventEntity):
         self._trigger_event(self._state.event_type)
         self.async_write_ha_state()
 
+    @callback
+    def _on_device_update(self) -> None:
+        """Call when device updates or entry data changes."""
+        super()._on_device_update()
+        if self._entry_data.available:
+            # Event entities should go available directly
+            # when the device comes online and not wait
+            # for the next data push.
+            self.async_write_ha_state()
+
 
 async_setup_entry = partial(
     platform_async_setup_entry,

tests/components/esphome/test_event.py

@@ -4,6 +4,7 @@ from aioesphomeapi import APIClient, Event, EventInfo
 import pytest
 
 from homeassistant.components.event import EventDeviceClass
+from homeassistant.const import STATE_UNAVAILABLE
 from homeassistant.core import HomeAssistant
 
 
@@ -11,9 +12,9 @@ from homeassistant.core import HomeAssistant
 async def test_generic_event_entity(
     hass: HomeAssistant,
     mock_client: APIClient,
-    mock_generic_device_entry,
+    mock_esphome_device,
 ) -> None:
-    """Test a generic event entity."""
+    """Test a generic event entity and its availability behavior."""
     entity_info = [
         EventInfo(
             object_id="myevent",
@@ -26,13 +27,31 @@ async def test_generic_event_entity(
     ]
     states = [Event(key=1, event_type="type1")]
     user_service = []
-    await mock_generic_device_entry(
+    device = await mock_esphome_device(
         mock_client=mock_client,
         entity_info=entity_info,
         user_service=user_service,
         states=states,
     )
+    await hass.async_block_till_done()
+
+    # Test initial state
     state = hass.states.get("event.test_myevent")
     assert state is not None
     assert state.state == "2024-04-24T00:00:00.000+00:00"
     assert state.attributes["event_type"] == "type1"
+
+    # Test device becomes unavailable
+    await device.mock_disconnect(True)
+    await hass.async_block_till_done()
+    state = hass.states.get("event.test_myevent")
+    assert state.state == STATE_UNAVAILABLE
+
+    # Test device becomes available again
+    await device.mock_connect()
+    await hass.async_block_till_done()
+
+    # Event entity should be available immediately without waiting for data
+    state = hass.states.get("event.test_myevent")
+    assert state.state == "2024-04-24T00:00:00.000+00:00"
+    assert state.attributes["event_type"] == "type1"