User.js

const mongoose = require('mongoose');
const { isEmail } = require('validator');
const bycrypt = require('bcrypt');

const userSchema = new mongoose.Schema({
  email: {
    type: String,
    required: [true, 'Please enter an email'],
    unique: true,
    lowercase: true,
    validate: [isEmail, 'Please enter a valid email']
  },
  password: {
    type: String,
    required: [true, 'Please enter a password'],
    minlength: [6, 'Minimum password length is 6 characters'],
  }
});

// fire a function after doc saveed to db
userSchema.post('save', function(doc, next){
  console.log('new user created &saved');
  next()
})

// fire a function before doc saved to db in order to hash the password
userSchema.pre('save', async function(next){
  const salt = await bycrypt.genSalt();
  this.password = await bycrypt.hash(this.password, salt); 
  next();
})

//static method to login user
userSchema.statics.login = async function(email, password){
  const user = await this.findOne({email});
  if(user){
    const auth = await bycrypt.compare(password, user.password);
    if(auth){
      return user;
    }throw Error('incorrect password');
  }throw Error('incorrect email');
}

const User = mongoose.model('user', userSchema);

module.exports = User;