Add service entity context (#71558)

Co-authored-by: Shay Levy <levyshay1@gmail.com>

homeassistant/helpers/service.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Awaitable, Callable, Iterable
+from contextvars import ContextVar
 import dataclasses
 from functools import partial, wraps
 import logging
@@ -63,6 +64,15 @@ _LOGGER = logging.getLogger(__name__)
 SERVICE_DESCRIPTION_CACHE = "service_description_cache"
 
 
+_current_entity: ContextVar[str | None] = ContextVar("current_entity", default=None)
+
+
+@callback
+def async_get_current_entity() -> str | None:
+    """Get the current entity on which the service is called."""
+    return _current_entity.get()
+
+
 class ServiceParams(TypedDict):
     """Type for service call parameters."""
 
@@ -706,6 +716,7 @@ async def _handle_entity_call(
 ) -> None:
     """Handle calling service method."""
     entity.async_set_context(context)
+    _current_entity.set(entity.entity_id)
 
     if isinstance(func, str):
         result = hass.async_run_job(partial(getattr(entity, func), **data))  # type: ignore[arg-type]

tests/helpers/test_service.py

@@ -19,12 +19,12 @@ from homeassistant.const import (
     STATE_ON,
 )
 from homeassistant.helpers import (
+    config_validation as cv,
     device_registry as dev_reg,
     entity_registry as ent_reg,
     service,
     template,
 )
-import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import EntityCategory
 from homeassistant.setup import async_setup_component
 
@@ -1205,3 +1205,17 @@ async def test_async_extract_config_entry_ids(hass):
     )
 
     assert await service.async_extract_config_entry_ids(hass, call) == {"abc"}
+
+
+async def test_current_entity_context(hass, mock_entities):
+    """Test we set the current entity context var."""
+
+    async def mock_service(entity, call):
+        assert entity.entity_id == service.async_get_current_entity()
+
+    await service.entity_service_call(
+        hass,
+        [Mock(entities=mock_entities)],
+        mock_service,
+        ha.ServiceCall("test_domain", "test_service", {"entity_id": "light.kitchen"}),
+    )