Add the tests for the service manager

tests/service/test_service_manager.py

@@ -0,0 +1,33 @@
+from pilgrim.service.servicemanager import ServiceManager
+from unittest.mock import patch, MagicMock
+
+def test_initial_state_is_none():
+    manager = ServiceManager()
+    assert manager.get_session() is None
+    assert manager.get_entry_service() is None
+    assert manager.get_photo_service() is None
+    assert manager.get_travel_diary_service() is None
+
+@patch('pilgrim.service.servicemanager.TravelDiaryService')
+@patch('pilgrim.service.servicemanager.PhotoService')
+@patch('pilgrim.service.servicemanager.EntryService')
+def test_get_services_instantiates_with_correct_session(
+    mock_entry_service, mock_photo_service, mock_travel_diary_service
+):
+    manager = ServiceManager()
+    mock_session = MagicMock()
+    manager.set_session(mock_session)
+
+    entry_service_instance = manager.get_entry_service()
+    photo_service_instance = manager.get_photo_service()
+    travel_diary_service_instance = manager.get_travel_diary_service()
+
+    mock_entry_service.assert_called_once()
+    mock_photo_service.assert_called_once()
+    mock_travel_diary_service.assert_called_once()
+    mock_entry_service.assert_called_once_with(mock_session)
+    mock_photo_service.assert_called_once_with(mock_session)
+    mock_travel_diary_service.assert_called_once_with(mock_session)
+    assert entry_service_instance == mock_entry_service.return_value
+    assert photo_service_instance == mock_photo_service.return_value
+    assert travel_diary_service_instance == mock_travel_diary_service.return_value