Fail tests which leak hass instances

homeassistant/core.py

@@ -41,6 +41,7 @@ from typing import (
     final,
     overload,
 )
+import weakref
 
 from propcache.api import cached_property, under_cached_property
 import voluptuous as vol
@@ -409,6 +410,9 @@ class CoreState(enum.Enum):
         return self.value
 
 
+hass_instances: list[weakref.ref[HomeAssistant]] = []
+
+
 class HomeAssistant:
     """Root object of the Home Assistant home automation."""
 
@@ -419,6 +423,7 @@ class HomeAssistant:
     def __new__(cls, config_dir: str) -> Self:
         """Set the _hass thread local data."""
         hass = super().__new__(cls)
+        hass_instances.append(weakref.ref(hass))
         _hass.hass = hass
         return hass
 

tests/conftest.py

@@ -288,8 +288,25 @@ def garbage_collection() -> None:
     handles the most common cases and let each module override
     to run per test case if needed.
     """
+    start_live_hass_instances = len(
+        [hass() for hass in ha.hass_instances if hass() is not None]
+    )
+    yield
     gc.collect()
-    gc.freeze()
+    end_live_hass_instances = len(
+        [hass() for hass in ha.hass_instances if hass() is not None]
+    )
+    if abs(start_live_hass_instances - end_live_hass_instances) > 1:
+        _LOGGER.error(
+            "Garbage collection did not clean up all Home Assistant instances. "
+            "Start: %s, End: %s",
+            start_live_hass_instances,
+            end_live_hass_instances,
+        )
+        pytest.fail(
+            f"Garbage collection did not clean up all Home Assistant instances. "
+            f"Start: {start_live_hass_instances}, End: {end_live_hass_instances}"
+        )
 
 
 @pytest.fixture(autouse=True)
@@ -1325,7 +1342,8 @@ def disable_translations_once(
     translations_once.start()
 
 
-@pytest_asyncio.fixture(autouse=True, scope="session", loop_scope="session")
+# @pytest_asyncio.fixture(autouse=True, scope="session", loop_scope="session")
+@pytest_asyncio.fixture(autouse=True)
 async def mock_zeroconf_resolver() -> AsyncGenerator[_patch]:
     """Mock out the zeroconf resolver."""
     resolver = AsyncResolver()