def test_save_config_to_file(self): # Given config = { 'db_path': 'db.json', 'language': 'en', 'logger_path': 'logger.json' } with open(self.config_file_name, "w") as f: json.dump(config, f) config_manager = ConfigManager(self.config_file_name) setattr(config_manager, 'db_path', 'db2.json') # When config_manager.save_configuration() # Then with open(self.config_file_name) as f: config = json.load(f) self.assertEqual(config['db_path'], 'db2.json')