Add TagProtocol for type checking (#81086)

* Add TagProtocol for type checking

* Adjust type hints

homeassistant/components/esphome/__init__.py

@@ -5,7 +5,7 @@ from collections.abc import Callable
 import functools
 import logging
 import math
-from typing import Any, Generic, NamedTuple, TypeVar, cast, overload
+from typing import TYPE_CHECKING, Any, Generic, NamedTuple, TypeVar, cast, overload
 
 from aioesphomeapi import (
     APIClient,
@@ -55,6 +55,9 @@ from .domain_data import DOMAIN, DomainData
 # Import config flow so that it's added to the registry
 from .entry_data import RuntimeEntryData
 
+if TYPE_CHECKING:
+    from homeassistant.components.tag import TagProtocol
+
 CONF_NOISE_PSK = "noise_psk"
 _LOGGER = logging.getLogger(__name__)
 _R = TypeVar("_R")
@@ -133,7 +136,7 @@ async def async_setup_entry(  # noqa: C901
             if service_name == "tag_scanned" and device_id is not None:
                 # Importing tag via hass.components in case it is overridden
                 # in a custom_components (custom_components.tag)
-                tag = hass.components.tag
+                tag: TagProtocol = hass.components.tag
                 tag_id = service_data["tag_id"]
                 hass.async_create_task(tag.async_scan_tag(tag_id, device_id))
                 return

homeassistant/components/tag/__init__.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import logging
+from typing import Protocol
 import uuid
 
 import voluptuous as vol
@@ -106,9 +107,21 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
     return True
 
 
+class TagProtocol(Protocol):
+    """Protocol for type checking."""
+
+    async def async_scan_tag(
+        self, tag_id: str, device_id: str | None, context: Context | None = None
+    ) -> None:
+        """Handle when a tag is scanned."""
+
+
 @bind_hass
 async def async_scan_tag(
-    hass: HomeAssistant, tag_id: str, device_id: str, context: Context | None = None
+    hass: HomeAssistant,
+    tag_id: str,
+    device_id: str | None,
+    context: Context | None = None,
 ) -> None:
     """Handle when a tag is scanned."""
     if DOMAIN not in hass.config.components:

homeassistant/components/tag/trigger.py

@@ -1,4 +1,6 @@
 """Support for tag triggers."""
+from __future__ import annotations
+
 import voluptuous as vol
 
 from homeassistant.const import CONF_PLATFORM
@@ -26,8 +28,10 @@ async def async_attach_trigger(
 ) -> CALLBACK_TYPE:
     """Listen for tag_scanned events based on configuration."""
     trigger_data = trigger_info["trigger_data"]
-    tag_ids = set(config[TAG_ID])
+    tag_ids: set[str] = set(config[TAG_ID])
-    device_ids = set(config[DEVICE_ID]) if DEVICE_ID in config else None
+    device_ids: set[str] | None = (
+        set(config[DEVICE_ID]) if DEVICE_ID in config else None
+    )
 
     job = HassJob(action)