passport.js

const LocalStrategy = require('passport-local').Strategy;

module.exports = function(passport){
  passport.use(
    new LocalStrategy({usernameField: 'email'}, (email, password, done) => {
      // ... do the database stuff with email and passsword and get all the details 
      // of user. In this case I am hardcoding the user.
      const user = {
        email
      }
      if(user){
      done(null, user);
      }
      else{
        done(null, false, {message: "Incorrect username"});
      }
    })
  )
  
  
  passport.serializeUser(function(user, done) {
    done(null, user.email);
  });
  
  
  passport.deserializeUser((email, done) => {
    // Find user by the email from your db
    const user = {
      email,
      name: 'Piyush', // In future, this value would come from your db
    }
    done(null, user)

  })
}