test: add comprehensive tests for IMAP, OpenAI, send_to_all, config_loader, and diagnostic APIs

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

tests/test_config_loader.py

@@ -1,8 +1,15 @@
 """Tests for app/utils/config_loader.py module."""
 
+from typing import Optional, Union
+from unittest.mock import MagicMock, patch
+
 import pytest
 
-from app.utils.config_loader import convert_setting_value
+from app.utils.config_loader import (
+    convert_setting_value,
+    load_settings_from_db,
+    reload_settings_from_db,
+)
 
 
 @pytest.mark.unit
@@ -58,3 +65,141 @@ class TestConvertSettingValue:
         """Test converting comma-separated string to list."""
         result = convert_setting_value("a, b, c", list)
         assert result == ["a", "b", "c"]
+
+    def test_handles_optional_type(self):
+        """Test handling Optional type annotation."""
+        result = convert_setting_value("42", Optional[int])
+        assert result == 42
+
+    def test_handles_union_type(self):
+        """Test handling Union type annotation."""
+        result = convert_setting_value("test", Union[str, None])
+        assert result == "test"
+
+    def test_list_from_empty_string(self):
+        """Test converting empty comma string to empty list."""
+        result = convert_setting_value("", list)
+        assert result == []
+
+    def test_list_with_whitespace(self):
+        """Test list conversion handles extra whitespace."""
+        result = convert_setting_value("  a  ,  b  ,  c  ", list)
+        assert result == ["a", "b", "c"]
+
+    def test_bool_variants(self):
+        """Test various boolean string representations."""
+        assert convert_setting_value("1", bool) is True
+        assert convert_setting_value("y", bool) is True
+        assert convert_setting_value("t", bool) is True
+        assert convert_setting_value("0", bool) is False
+        assert convert_setting_value("n", bool) is False
+
+
+@pytest.mark.unit
+class TestLoadSettingsFromDb:
+    """Tests for load_settings_from_db function."""
+
+    def test_loads_settings_from_database(self):
+        """Test loading settings from database."""
+        from app.models import ApplicationSettings
+
+        # Mock settings object
+        mock_settings = MagicMock()
+        mock_settings.__fields__ = {
+            "test_setting": MagicMock(annotation=str),
+            "another_setting": MagicMock(annotation=int),
+        }
+
+        # Mock database session
+        mock_db = MagicMock()
+        mock_db_settings = [
+            ApplicationSettings(key="test_setting", value="test_value"),
+            ApplicationSettings(key="another_setting", value="42"),
+        ]
+        mock_db.query.return_value.all.return_value = mock_db_settings
+
+        load_settings_from_db(mock_settings, mock_db)
+
+        # Verify settings were set
+        assert mock_settings.test_setting == "test_value"
+        assert mock_settings.another_setting == 42
+
+    def test_handles_empty_database(self):
+        """Test handling when no settings in database."""
+        mock_settings = MagicMock()
+        mock_db = MagicMock()
+        mock_db.query.return_value.all.return_value = []
+
+        # Should not raise
+        load_settings_from_db(mock_settings, mock_db)
+
+    def test_skips_unknown_settings(self):
+        """Test that unknown settings are skipped."""
+        from app.models import ApplicationSettings
+
+        mock_settings = MagicMock()
+        mock_settings.__fields__ = {"known_setting": MagicMock(annotation=str)}
+
+        mock_db = MagicMock()
+        mock_db_settings = [
+            ApplicationSettings(key="known_setting", value="value1"),
+            ApplicationSettings(key="unknown_setting", value="value2"),
+        ]
+        mock_db.query.return_value.all.return_value = mock_db_settings
+
+        load_settings_from_db(mock_settings, mock_db)
+
+        # Only known_setting should be set
+        assert hasattr(mock_settings, "known_setting")
+
+    def test_handles_database_errors(self):
+        """Test handling database errors gracefully."""
+        mock_settings = MagicMock()
+        mock_db = MagicMock()
+        mock_db.query.side_effect = Exception("Database error")
+
+        # Should not raise, just log warning
+        load_settings_from_db(mock_settings, mock_db)
+
+
+@pytest.mark.unit
+class TestReloadSettingsFromDb:
+    """Tests for reload_settings_from_db function."""
+
+    @patch("app.utils.config_loader.SessionLocal")
+    @patch("app.utils.config_loader.load_settings_from_db")
+    def test_reload_success(self, mock_load, mock_session_local):
+        """Test successful settings reload."""
+        mock_settings = MagicMock()
+        mock_db = MagicMock()
+        mock_session_local.return_value = mock_db
+
+        result = reload_settings_from_db(mock_settings)
+
+        assert result is True
+        mock_load.assert_called_once_with(mock_settings, mock_db)
+        mock_db.close.assert_called_once()
+
+    @patch("app.utils.config_loader.SessionLocal")
+    def test_reload_database_error(self, mock_session_local):
+        """Test reload handling database error."""
+        mock_settings = MagicMock()
+        mock_session_local.side_effect = Exception("Connection error")
+
+        result = reload_settings_from_db(mock_settings)
+
+        assert result is False
+
+    @patch("app.utils.config_loader.SessionLocal")
+    def test_reload_closes_session_on_error(self, mock_session_local):
+        """Test that session is closed even on error."""
+        mock_settings = MagicMock()
+        mock_db = MagicMock()
+        mock_db.query.side_effect = Exception("Query error")
+        mock_session_local.return_value = mock_db
+
+        result = reload_settings_from_db(mock_settings)
+
+        # Should close session despite error
+        mock_db.close.assert_called_once()
+        assert result is False