text: const User = require('../models/user');
  
  const registerUser = (user) => {
      return user.save();
  }
  const getUserByEmail = (email) => {
      return User.findOne({ email });
  }
  const getUserById = (id) => {
      return User.findOne({ _id: id });
  }
  const userService = {
      registerUser,
      getUserByEmail,
      getUserById,
  }
  module.exports = userService;
  