I'm trying to create delete operation. I have a user and tasks to do. Each user has a list of tasks assigned. Here is my code of delete operation:

const Mutation = new GraphQLObjectType({
    name: 'Mutation',
    fields: {
        deleteUser: {
            type: UserType,
            args: {
                id: { type: new GraphQLNonNull(GraphQLID) }
            },
            resolve(parent, args){
                var id = (args.id).toString()
                let todos = Todo.find({ user_id: id });
                let user = User.findById(args.id);
                todos.remove();
                user.findOneAndRemove();
                return todos;
            }
        }
    }
})

And here are my defined types:

const ToDoType = new GraphQLObjectType({
    name: 'todoItem',
    fields: () => ({
        id: {type: GraphQLID},
        title: {type: GraphQLString},
        completed: {type: GraphQLBoolean},
        user: {
            type: UserType,
            resolve(parent, args){
                return User.findById(parent.user_id);
            }
        }
    })
});

const UserType = new GraphQLObjectType({
    name: 'user',
    fields: () => ({
        id: {type: GraphQLID},
        name: {type: GraphQLString},
        email: {type: GraphQLString},
        login: {type: GraphQLString},
        todos: {
            type: new GraphQLList(ToDoType),
            resolve(parent, args){
                return Todo.find({ user_id: parent.id })
            }
        }
    })
});

The problem is that while deleting user I want to delete all his "to do's" but according to what I put in return I can delete only one thing.. So now I have "return todos" and it deletes only todo assigned to user, but not the user. When I put there "return user" it will delete only user without his tasks. How can I delete user and his tasks at once?