passport.js

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

function initialize(getUserByUsername, getUserById) {
  const authenticateUser = async (username, password, done) => {
    const user = getUserByUsername(username);
    if (user == null) {
      return done(null, false, { message: "No user with that username" });
    }

    try {
      if (await 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: "username", passwordField: "password" },
      authenticateUser
    )
  );
  passport.serializeUser((user, done) => done(null, user.id));
  passport.deserializeUser((id, done) => {
    return done(null, getUserById(id));
  });
}

module.exports = initialize;