Fix unused snapshots not triggering failure in CI (#128162)

tests/conftest.py

@@ -36,6 +36,7 @@ import pytest_socket
 import requests_mock
 import respx
 from syrupy.assertion import SnapshotAssertion
+from syrupy.session import SnapshotSession
 
 from homeassistant import block_async_io
 from homeassistant.exceptions import ServiceNotFound
@@ -92,7 +93,7 @@ from homeassistant.util.async_ import create_eager_task, get_scheduled_timer_han
 from homeassistant.util.json import json_loads
 
 from .ignore_uncaught_exceptions import IGNORE_UNCAUGHT_EXCEPTIONS
-from .syrupy import HomeAssistantSnapshotExtension
+from .syrupy import HomeAssistantSnapshotExtension, override_syrupy_finish
 from .typing import (
     ClientSessionGenerator,
     MockHAClientWebSocket,
@@ -149,6 +150,11 @@ def pytest_configure(config: pytest.Config) -> None:
     if config.getoption("verbose") > 0:
         logging.getLogger().setLevel(logging.DEBUG)
 
+    # Override default finish to detect unused snapshots despite xdist
+    # Temporary workaround until it is finalised inside syrupy
+    # See https://github.com/syrupy-project/syrupy/pull/901
+    SnapshotSession.finish = override_syrupy_finish
+
 
 def pytest_runtest_setup() -> None:
     """Prepare pytest_socket and freezegun.