Add one more test

tests/manager/api/test_app.py

@@ -1,6 +1,11 @@
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 
-from palace.manager.api.app import initialize_application
+import pytest
+
+from palace.manager.api.app import (
+    initialize_application,
+    initialize_circulation_manager,
+)
 from palace.manager.util.http import HTTP
 from tests.fixtures.database import DatabaseTransactionFixture
 from tests.fixtures.services import ServicesFixture
@@ -23,3 +28,30 @@ def test_initialize_application_http(
 
     # Make sure that the HTTP configuration was set
     mock_set_quick_failure_settings.assert_called_once()
+
+
+def test_initialize_circulation_manager(caplog: pytest.LogCaptureFixture):
+    with (
+        patch("palace.manager.api.app.app") as mock_app,
+        patch("palace.manager.api.app.CirculationManager") as mock_circulation_manager,
+        patch("palace.manager.api.app.CachedData") as mock_cached_data,
+    ):
+        # If app is already initialized, it should not be re-initialized
+        mock_app.manager = MagicMock()
+        initialize_circulation_manager()
+        mock_circulation_manager.assert_not_called()
+        mock_cached_data.initialize.assert_not_called()
+
+        # If app is not initialized, it should be initialized
+        mock_app.manager = None
+        initialize_circulation_manager()
+        mock_circulation_manager.assert_called_once()
+        mock_cached_data.initialize.assert_called_once()
+        assert mock_app.manager == mock_circulation_manager.return_value
+
+        # If an exception is raised, it should be logged
+        mock_app.manager = None
+        mock_circulation_manager.side_effect = Exception("Test exception")
+        with pytest.raises(Exception):
+            initialize_circulation_manager()
+        assert "Error instantiating circulation manager!" in caplog.text