def test_get_restaurant_name_by_id_invalid():
    """
    Test that get_restaurant_name_by_id() returns "" for invalid ids.
    """
    with app.app_context():
        rpm = RestaurantProfileManager("")
        username = rpm.get_restaurant_name_by_id("not a real id")
        assert username == ""
def test_get_restaurant_name_by_id_valid():
    """
    Test that get_restaurant_name_by_id() returns the restaurant name of a valid user correctly.
    """
    with app.app_context():
        rpm = RestaurantProfileManager("")
        username = rpm.get_restaurant_name_by_id("5f15c084143cb39bfc5619b8")
        assert username == "KFC"