TypeError: LocalStrategy requires a verify callback

Question

I was learning express framework, have included passport, passport-session in it. Now I am getting this error

TypeError: LocalStrategy requires a verify callback(check the image below):

And tell you what, this error belongs to passport-session module, but I know, I must not change any file in node_modules folder, but I think this is what it wants! And so, I am stuck!

You can check my app.js file as well:

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var expressValidator = require('express-validator');
var session = require('passport-session');
var passport = require('passport');
var localStrategy = require('passport-local').Strategy;
var multer = require('multer');
var upload = multer({dest: './uploads'});
var flash = require('connect-flash');
var mongo = require('mongodb');
var mongoose = require('mongoose')
var db = mongoose.connection;

var index = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));


//Handle Sessions
app.use(session({
  secret: 'keyboardcat',
  resave: true,
  saveUninitialized: true
}));

app.use(passport.initialize());
app.use(passport.session());

//Validator
app.use(expressValidator({
  errorFormatter: function(param, msg, value) {
      var namespace = param.split('.')
      , root    = namespace.shift()
      , formParam = root;

    while(namespace.length) {
      formParam += '[' + namespace.shift() + ']';
    }
    return {
      param : formParam,
      msg   : msg,
      value : value
    };
  }
}));

app.use(flash());
app.use(function (req, res, next) {
  res.locals.messages = require('express-messages')(req, res);
  next();
});


app.use('/', index);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

Can anyone please help me find the cause and solution? Thanks!

Note: I have searched google as well, saw many similar questions like it but not getting any solution for this, or they doesn't seem to relate to this problem!

Note 2: The tutorial I followed, I did exactly the same steps as them, but I am getting error, not them!

Answer 1

You have to define a validation function for your local strategy. For example:

passport.use(new LocalStrategy(
  function(username, password, done) {
    User.findOne({ username: username }, function (err, user) {
      if (err) { return done(err); }
      if (!user) { return done(null, false); }
      if (!user.verifyPassword(password)) { return done(null, false); }
      return done(null, user);
    });
  }
));

Read more about this authentication strategy on passport-local github page.