passport-config.js

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

function initialize(passport, getUserByEmail, getUserById) {
  const authenticateUser = async (email, password, done) => {
    const user = await getUserByEmail(email);
    if (user.username == null) {
      return done(null, false, { message: 'No user with that email' });
    };

    try {
      if (bcrypt.compare(password, user.password)) {
        return done(null, user);
      } else {
        return done(null, false, { message: 'Password incorrect' });
      }
    } catch (e) {
      return done(e);
    }
  };

  passport.use(new LocalStrategy({ usernameField: 'email' }, authenticateUser));
  passport.serializeUser((user, done) => done(null, user.id));
  passport.deserializeUser(async (id, done) => {
    try {
      const user = await getUserById(id);
      if(!user) {
        return done(null, null);
      }
      return done(null, user);
    } catch(err) {
      console.log(err);
      return done(err, null);
    }
  })
}

module.exports = initialize;