test: prime pycares shutdown thread at session scope; revert oauth band-aid

The CI Python 3.12 leg backtracks to homeassistant 2025.1.4 / pytest-HA-CC
0.13.205, whose lingering-thread check has no whitelist for the
_run_safe_shutdown_loop daemon that aiohttp's aiodns resolver (pycares) spawns
the first time a test builds a clientsession. Whichever session-creating test
runs first gets blamed -- so the previous per-test hermetic fix in
test_oauth.py just moved the failure to test_oauth_wiring.py.

Root fix: a session-scoped autouse fixture in conftest.py starts pycares'
shared shutdown-manager thread once, before verify_cleanup snapshots
threads_before. The thread is then in every test's baseline and never counted
as leaked -- covering all current and future clientsession tests without
lowering fidelity. pycares' start() is idempotent and its loop only blocks on a
queue (no socket/DNS/event loop), so it is safe under pytest-socket. Validated
against the exact CI pycares version (5.0.1).

Revert the test_oauth.py boundary-mock band-aid now that the fixture makes the
original aioresponses test (which exercises the real envelope parse) safe again.

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

Author: geofffranks

tests/conftest.py

@@ -35,6 +35,31 @@
     MockConfigEntry = None  # type: ignore
 
 
+@pytest.fixture(autouse=True, scope="session")
+def _prime_pycares_shutdown_thread():
+    """Pre-spawn pycares' ``_run_safe_shutdown_loop`` daemon before per-test
+    thread snapshots, so the lingering-thread check never blames a test for it.
+
+    aiohttp's aiodns resolver lazily starts this shared daemon the first time
+    any test builds a clientsession (e.g. a real OAuth token refresh). Older
+    pytest-homeassistant-custom-component builds have no whitelist for it in
+    their cleanup check, so the *first* such test fails teardown — on the
+    Python 3.12 CI leg, pip backtracks to homeassistant 2025.1.4 /
+    pytest-HA-CC 0.13.205, which predates the whitelist. Starting the thread
+    once at session scope (this fixture runs before the function-scoped
+    ``verify_cleanup``) puts it in every test's ``threads_before`` baseline, so
+    it is never counted as leaked. The loop only blocks on a queue — no socket,
+    DNS, or event loop — so it is safe under pytest-socket.
+    """
+    try:
+        import pycares
+
+        pycares._shutdown_manager.start()
+    except (ImportError, AttributeError):  # pragma: no cover — pycares internals shifted
+        pass
+    yield
+
+
 @pytest.fixture(autouse=True)
 def auto_enable_custom_integrations(enable_custom_integrations):
     """Automatically enable loading custom components in tests."""

tests/test_oauth.py

@@ -7,12 +7,9 @@
 goes stale. These cover the unwrap and its wiring into the implementations.
 """
 
-from unittest.mock import AsyncMock, patch
-
+from aioresponses import aioresponses
 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,
@@ -46,23 +43,12 @@ def test_unwrap_raises_when_no_access_token_present():
 
 
 async def test_local_impl_token_request_unwraps(hass):
-    """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.
-    """
+    """_token_request against the real {code,data} envelope returns standard fields."""
     impl = UtecLocalOAuth2Implementation(
         hass, DOMAIN, "client-id", "client-secret", OAUTH2_AUTHORIZE, OAUTH2_TOKEN,
     )
-    with patch.object(
-        config_entry_oauth2_flow.LocalOAuth2Implementation,
-        "_token_request",
-        new=AsyncMock(return_value=_WRAPPED),
-    ):
+    with aioresponses() as mock:
+        mock.post(OAUTH2_TOKEN, payload=_WRAPPED)
         result = await impl._token_request(
             {"grant_type": "refresh_token", "refresh_token": "r"}
         )