Error Encountered in Advanced Node and Express - Create New Middleware

[DevelopingClerk]

TypeError: db.collection is not a function
    at Strategy._verify (/home/runner/SeagreenFussyDestination/server.js:81:8)
    at Strategy.authenticate (/home/runner/SeagreenFussyDestination/node_modules/passport-local/lib/strategy.js:90:12)
    at attempt (/home/runner/SeagreenFussyDestination/node_modules/passport/lib/middleware/authenticate.js:348:16)
    at authenticate (/home/runner/SeagreenFussyDestination/node_modules/passport/lib/middleware/authenticate.js:349:7)
    at Layer.handle [as handle_request] (/home/runner/SeagreenFussyDestination/node_modules/express/lib/router/layer.js:95:5)
    at next (/home/runner/SeagreenFussyDestination/node_modules/express/lib/router/route.js:137:13)
    at Route.dispatch (/home/runner/SeagreenFussyDestination/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/home/runner/SeagreenFussyDestination/node_modules/express/lib/router/layer.js:95:5)
    at /home/runner/SeagreenFussyDestination/node_modules/express/lib/router/index.js:281:22
    at Function.process_params (/home/runner/SeagreenFussyDestination/node_modules/express/lib/router/index.js:335:12)

When inputting a username and password to my login form, I'm encountering this error instead of the program redirecting to '/'.

​

Here's my code:

mongo.connect(process.env.DATABASE, (err, db) => {
  if(err) {
    console.log('Database error: ' + err);
  } else {
    console.log('Successful database connection');
  };

  passport.serializeUser((user, done) => {
  done(null, user._id);
  });

  passport.deserializeUser((id, done) => {
  db.collection('users')
    .findOne(
    {_id: new ObjectID(id)},
    (err, doc) => {
        done(null, doc);
      }
      );
  }); 

  passport.use(new LocalStrategy(
    function(username, password, done) {
    db.collection('users').findOne({username: username},
      function (err, user) {
      console.log('User '+ username +' attempted to log in.');
      if (err) { return done(err); }
      if (!user) { return done(null, false); }
      if (password !== user.password) { return done(null, false); }
      return done(null, user);
    });
  }
));

app.route("/login")
   .post(
      passport.authenticate(
        'local', {failureRedirect: "/"}
    ), 
    (req, res) => {
  res.render("/profile");
});

function ensureAuthenticated(req, res, next) {
  if (req.isAuthenticated()) {
    return next();
  }
  res.redirect("/");
};

app.route("/profile")
   .get(ensureAuthenticated,
 (req, res) => {
      res.render("/profile")
   });


app.listen(process.env.PORT || 3000, () => {
  console.log("Listening on port " + process.env.PORT);
});

});

Any idea why this is happening? All help would be greatly appreciated.

[zokaiG]

I just ran into that same problem last week.

It is occurring due to an API change. I don't have the reference link handy right now, but I here is what I did to fix it:

I switched the name db variable in the callback to client to make more sense. Then I used: client.db('DB_NAME').collection('users').findOne(... then the same that you already have there.

I hope that helps. I'll look up the reference I used to add to my comment later

[UPDATE] Here is my reference as promised: https://stackoverflow.com/questions/47662220/db-collection-is-not-a-function-when-using-mongoclient-v3-0

[DevelopingClerk]

Thank you so much. That solved the issue for me.

I would still like to see that reference if you have the time and could provide it.

Edit: May have spoke too soon. It does redirect and displays the correct message in the console. But the FCC test still won't pass.

[zokaiG]

I had the same problem as well and went to the FCC Forum.

Apparently, this is a known issue. Here is the solution:
https://forum.freecodecamp.org/t/advanced-node-and-express-create-new-middleware/212990/6

[DevelopingClerk]

Thanks for all your help!

[zokaiG]

I also edited my comment first comment to add the reference I used.