Replace process-local session cache with pluggable session cache backend

backend/tests/test_routers/test_auth.py

@@ -209,13 +209,11 @@ class TestRequireAuthSessionCache:
     """In-memory session token cache inside ``require_auth``."""
 
     @pytest.fixture(autouse=True)
-    def reset_cache(self) -> Generator[None, None, None]:
+    def reset_cache(self, client: AsyncClient) -> Generator[None, None, None]:
         """Flush the session cache before and after every test in this class."""
-        from app import dependencies
-
-        dependencies.clear_session_cache()
+        client._transport.app.state.session_cache.clear()
         yield
-        dependencies.clear_session_cache()
+        client._transport.app.state.session_cache.clear()
 
     @pytest.fixture(autouse=True)
     def enable_session_cache(self, client: AsyncClient) -> Generator[None, None, None]:
@@ -237,9 +235,7 @@ class TestRequireAuthSessionCache:
         token = await _login(client)
 
         # Ensure cache is empty so the first request definitely hits the DB.
-        from app import dependencies
-
-        dependencies.clear_session_cache()
+        client._transport.app.state.session_cache.clear()
 
         call_count = 0
         original_get_session = session_repo.get_session
@@ -268,27 +264,25 @@ class TestRequireAuthSessionCache:
     async def test_token_enters_cache_after_first_auth(
         self, client: AsyncClient
     ) -> None:
-        """A successful auth request places the token in ``_session_cache``."""
-        from app import dependencies
+        """A successful auth request places the token in the session cache."""
 
         await _do_setup(client)
         token = await _login(client)
 
-        dependencies.clear_session_cache()
-        assert token not in dependencies._session_cache
+        client._transport.app.state.session_cache.clear()
+        assert client._transport.app.state.session_cache.get(token) is None
 
         await client.get(
             "/api/dashboard/status",
             headers={"Authorization": f"Bearer {token}"},
         )
 
-        assert token in dependencies._session_cache
+        assert client._transport.app.state.session_cache.get(token) is not None
 
     async def test_logout_evicts_token_from_cache(
         self, client: AsyncClient
     ) -> None:
-        """Logout removes the session token from the in-memory cache immediately."""
-        from app import dependencies
+        """Logout removes the session token from the session cache immediately."""
 
         await _do_setup(client)
         token = await _login(client)
@@ -298,14 +292,14 @@ class TestRequireAuthSessionCache:
             "/api/dashboard/status",
             headers={"Authorization": f"Bearer {token}"},
         )
-        assert token in dependencies._session_cache
+        assert client._transport.app.state.session_cache.get(token) is not None
 
         # Logout must evict the entry.
         await client.post(
             "/api/auth/logout",
             headers={"Authorization": f"Bearer {token}"},
         )
-        assert token not in dependencies._session_cache
+        assert client._transport.app.state.session_cache.get(token) is None
 
         response = await client.get("/api/health")
         assert response.status_code == 200