User.js

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

const userSchema = 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 before doc is saved to db
userSchema.pre('save',async function(next){
    const salt = await bcrypt.genSalt();
    this.password = await bcrypt.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 bcrypt.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;