Fix evict_faked_translations fixture (#159419)

Co-authored-by: epenet <6771947+epenet@users.noreply.github.com>

tests/conftest.py

@@ -1270,9 +1270,11 @@ def evict_faked_translations(translations_once) -> Generator[_patch]:
     component_paths = components.__path__
 
     for call in mock_component_strings.mock_calls:
+        _components: set[str] = call.args[2]
         integrations: dict[str, loader.Integration] = call.args[3]
-        for domain, integration in integrations.items():
-            if any(
+        for domain in _components:
+            # If the integration exists, don't evict from cache
+            if (integration := integrations.get(domain)) and any(
                 pathlib.Path(f"{component_path}/{domain}") == integration.file_path
                 for component_path in component_paths
             ):

tests/test_test_fixtures.py

@@ -1,6 +1,6 @@
 """Test test fixture configuration."""
 
-from collections.abc import Generator
+from collections.abc import Callable, Generator
 from http import HTTPStatus
 import pathlib
 import socket
@@ -90,17 +90,36 @@ async def test_evict_faked_translations_assumptions(hass: HomeAssistant) -> None
     assert integration.file_path == pathlib.Path("custom_components/test")
 
 
-async def test_evict_faked_translations(hass: HomeAssistant, translations_once) -> None:
-    """Test the evict_faked_translations fixture."""
+@pytest.mark.parametrize(
+    "prepare_integration",
+    [
+        # Fake integration backed by a module
+        lambda hass: mock_integration(hass, MockModule("test"), built_in=True),
+        # fake integration not backed by a module
+        lambda hass: None,
+    ],
+)
+async def test_evict_faked_translations(
+    hass: HomeAssistant,
+    translations_once,
+    prepare_integration: Callable[[HomeAssistant], None],
+) -> None:
+    """Test the evict_faked_translations fixture.
+
+    In this test, we load translations for a fake integration, then ensure that
+    after the fixture is torn down, only the real integration remains in the
+    translations cache.
+    """
     cache: translation._TranslationsCacheData = translations_once.kwargs["return_value"]
     fake_domain = "test"
     real_domain = "homeassistant"
 
-    # Evict the real domain from the cache in case it's been loaded before
-    cache.loaded["en"].discard(real_domain)
+    if "en" in cache.loaded:
+        # Evict the real domain from the cache in case it's been loaded before
+        cache.loaded["en"].discard(real_domain)
 
-    assert fake_domain not in cache.loaded["en"]
-    assert real_domain not in cache.loaded["en"]
+        assert fake_domain not in cache.loaded["en"]
+        assert real_domain not in cache.loaded["en"]
 
     # The evict_faked_translations fixture has module scope, so we set it up and
     # tear it down manually
@@ -110,7 +129,8 @@ async def test_evict_faked_translations(hass: HomeAssistant, translations_once)
     # Set up the evict_faked_translations fixture
     next(gen)
 
-    mock_integration(hass, MockModule(fake_domain), built_in=True)
+    # Try loading translations for mock integration
+    prepare_integration(hass)
     await translation.async_load_integrations(hass, {fake_domain, real_domain})
     assert fake_domain in cache.loaded["en"]
     assert real_domain in cache.loaded["en"]