test(oauth): make token-request unwrap test hermetic

test_local_impl_token_request_unwraps drove a real refresh through HA's
LocalOAuth2Implementation._token_request, which builds an aiohttp clientsession
whose pycares DNS resolver leaves a daemon _run_safe_shutdown_loop thread. The
CI matrix runs Python 3.12, which backtracks to homeassistant 2025.1.4 +
pytest-homeassistant-custom-component 0.13.205 -- a build predating the
lingering-thread whitelist for that thread -- so teardown failed the test. It
passed locally on 3.13 / 0.13.316, which whitelists it.

Patch the superclass _token_request (HA's HTTP boundary) instead of mocking the
network, so no clientsession or pycares thread is created. The mixin unwrap
wiring is still exercised; {code,data} envelope handling stays covered by the
three pure _unwrap_utec_token tests and test_oauth_wiring.py. Version-agnostic:
passes on both the old and new pytest-HA-CC.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: geofffranks

tests/test_oauth.py

@@ -7,9 +7,12 @@
 goes stale. These cover the unwrap and its wiring into the implementations.
 """
 
-from aioresponses import aioresponses
+from unittest.mock import AsyncMock, patch
+
 import pytest
 
+from homeassistant.helpers import config_entry_oauth2_flow
+
 from custom_components.u_tec.const import DOMAIN, OAUTH2_AUTHORIZE, OAUTH2_TOKEN
 from custom_components.u_tec.oauth import (
     UtecLocalOAuth2Implementation,
@@ -43,12 +46,23 @@ def test_unwrap_raises_when_no_access_token_present():
 
 
 async def test_local_impl_token_request_unwraps(hass):
-    """_token_request against the real {code,data} envelope returns standard fields."""
+    """The mixin unwraps whatever the underlying HA token request returns.
+
+    We patch the superclass ``_token_request`` (HA's HTTP boundary) rather than
+    mock the network: hitting it for real spins up an aiohttp clientsession whose
+    pycares DNS resolver leaves a daemon ``_run_safe_shutdown_loop`` thread that
+    older pytest-homeassistant-custom-component builds flag as a lingering-thread
+    failure. Patching the boundary keeps the test hermetic and version-agnostic
+    while still proving the mixin is wired in and unwraps the {code,data} envelope.
+    """
     impl = UtecLocalOAuth2Implementation(
         hass, DOMAIN, "client-id", "client-secret", OAUTH2_AUTHORIZE, OAUTH2_TOKEN,
     )
-    with aioresponses() as mock:
-        mock.post(OAUTH2_TOKEN, payload=_WRAPPED)
+    with patch.object(
+        config_entry_oauth2_flow.LocalOAuth2Implementation,
+        "_token_request",
+        new=AsyncMock(return_value=_WRAPPED),
+    ):
         result = await impl._token_request(
             {"grant_type": "refresh_token", "refresh_token": "r"}
         )