Migrate esphome to use HassKey (#168873)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Copilot <copilot@github.com>

homeassistant/components/esphome/const.py

@@ -1,11 +1,20 @@
 """ESPHome constants."""
 
-from typing import Final
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Final
 
 from awesomeversion import AwesomeVersion
 
+from homeassistant.util.hass_dict import HassKey
+
+if TYPE_CHECKING:
+    from .domain_data import DomainData
+
 DOMAIN = "esphome"
 
+ESPHOME_DATA: HassKey[DomainData] = HassKey(DOMAIN)
+
 CONF_ALLOW_SERVICE_CALLS = "allow_service_calls"
 CONF_SUBSCRIBE_LOGS = "subscribe_logs"
 CONF_DEVICE_NAME = "device_name"

homeassistant/components/esphome/domain_data.py

@@ -4,12 +4,11 @@ from __future__ import annotations
 
 from dataclasses import dataclass, field
 from functools import cache
-from typing import Self
 
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.json import JSONEncoder
 
-from .const import DOMAIN
+from .const import ESPHOME_DATA
 from .entry_data import ESPHomeConfigEntry, ESPHomeStorage, RuntimeEntryData
 
 STORAGE_VERSION = 1
@@ -36,11 +35,9 @@ class DomainData:
             ),
         )
 
-    @classmethod
+    @staticmethod
     @cache
-    def get(cls, hass: HomeAssistant) -> Self:
+    def get(hass: HomeAssistant) -> DomainData:
         """Get the global DomainData instance stored in hass.data."""
-        # Uses legacy hass.data[DOMAIN] pattern
-        # pylint: disable-next=hass-use-runtime-data
-        ret = hass.data[DOMAIN] = cls()
+        ret = hass.data[ESPHOME_DATA] = DomainData()
         return ret