This is the stack trace: This happens when I run the server.js file in my project. Also I couldn't find any explanation on the web. Can someone help with this error please?

E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:341
  if ( this._mdb.s.topology.connections().length === 0 ) {                ^

TypeError: Cannot read property 's' of undefined
    at Agenda._findAndLockNextJob (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:341:17) at jobQueueFilling (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:420:10) at processJobs (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:404:7)

    at doNTCallback0 (node.js:417:9)
    at process._tickCallback (node.js:346:13)
    at Function.Module.runMain (module.js:469:11)
    at startup (node.js:134:18)
    at node.js:961:3

These are the only codes that are using angenda and "s" < as a string

var mongoConnectionString = "mongodb://127.0.0.1/agenda";
var agenda = require('agenda')({ db: { address: mongoConnectionString } });
var sugar = require('sugar');
var nodemailer = require('nodemailer');

// define an agenda job called send email alert.

agenda.define('send email alert', function (job, done) {
    // what should happen when send email alert job is dispatched. 
    // When this job runs, name of the show will be passed in as an optional data object. 
    // Since we are not storing the entire user document in subscribers array (only references), 
    // we have to use Mongoose’s populate method.
    Show.findOne({ name: job.attrs.data }).populate('subscribers').exec(function (err, show) {
        var emails = show.subscribers.map(function (user) {
            return user.email;
        });

        var upingEpisode = show.episodes.filter(function (episode) {
            return new Date(episode.firstAired) > new Date();
        })[0];

        var smtpTransport = nodemailer.createTransport('SMTP', {
            service: 'SendGrid',
            auth: { user: 'hslogin', pass: 'hspassword00' }
        });

        // standard Nodemailer boilerplate for sending emails.
        var mailOptions = {
            from: 'Fred Foo ✔ <[email protected]>',
            to: emails.join(','),
            subject: show.name + ' is starting soon!',
            text: show.name + ' starts in less than 2 hours on ' + showwork + '.\n\n' +
        'Episode ' + upingEpisode.episodeNumber + ' Overview\n\n' + upingEpisode.overview
        };

        smtpTransport.sendMail(mailOptions, function (error, response) {
            console.log('Message sent: ' + response.message);
            smtpTransport.close();
            done();
        });
    });
});

agenda.start();

agenda.on('start', function (job) {
    console.log("Job %s starting", job.attrs.name);
});

agenda.on('plete', function (job) {
    console.log("Job %s finished", job.attrs.name);
});

This is the stack trace: This happens when I run the server.js file in my project. Also I couldn't find any explanation on the web. Can someone help with this error please?

E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:341
  if ( this._mdb.s.topology.connections().length === 0 ) {                ^

TypeError: Cannot read property 's' of undefined
    at Agenda._findAndLockNextJob (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:341:17) at jobQueueFilling (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:420:10) at processJobs (E:\users\ashane\documents\visual studio 2015\Projects\ShowTracker\ShowTracker\node_modules\agenda\lib\agenda.js:404:7)

    at doNTCallback0 (node.js:417:9)
    at process._tickCallback (node.js:346:13)
    at Function.Module.runMain (module.js:469:11)
    at startup (node.js:134:18)
    at node.js:961:3

These are the only codes that are using angenda and "s" < as a string

var mongoConnectionString = "mongodb://127.0.0.1/agenda";
var agenda = require('agenda')({ db: { address: mongoConnectionString } });
var sugar = require('sugar');
var nodemailer = require('nodemailer');

// define an agenda job called send email alert.

agenda.define('send email alert', function (job, done) {
    // what should happen when send email alert job is dispatched. 
    // When this job runs, name of the show will be passed in as an optional data object. 
    // Since we are not storing the entire user document in subscribers array (only references), 
    // we have to use Mongoose’s populate method.
    Show.findOne({ name: job.attrs.data }).populate('subscribers').exec(function (err, show) {
        var emails = show.subscribers.map(function (user) {
            return user.email;
        });

        var upingEpisode = show.episodes.filter(function (episode) {
            return new Date(episode.firstAired) > new Date();
        })[0];

        var smtpTransport = nodemailer.createTransport('SMTP', {
            service: 'SendGrid',
            auth: { user: 'hslogin', pass: 'hspassword00' }
        });

        // standard Nodemailer boilerplate for sending emails.
        var mailOptions = {
            from: 'Fred Foo ✔ <[email protected]>',
            to: emails.join(','),
            subject: show.name + ' is starting soon!',
            text: show.name + ' starts in less than 2 hours on ' + showwork + '.\n\n' +
        'Episode ' + upingEpisode.episodeNumber + ' Overview\n\n' + upingEpisode.overview
        };

        smtpTransport.sendMail(mailOptions, function (error, response) {
            console.log('Message sent: ' + response.message);
            smtpTransport.close();
            done();
        });
    });
});

agenda.start();

agenda.on('start', function (job) {
    console.log("Job %s starting", job.attrs.name);
});

agenda.on('plete', function (job) {
    console.log("Job %s finished", job.attrs.name);
});

• javascript
• node.js
• visual-studio-2015

• That means the code is trying to access the property s of an object variable that is not defined. If you want more help, show us the code where this happens. Is the source file something you wrote, or a dependency you're using? – Antoine Commented Nov 4, 2015 at 7:28
• @Antoine These are the codes only use the agenda node modules – Ashane Alvis Commented Nov 4, 2015 at 8:12

2 Answers 2

it works when .on('ready') function is present. Here is my example.

var Agenda = require('agenda');
var agenda = new Agenda({db: { address: 'localhost:27017/servicebox-dev'}}); 
matcher.matchProviders(agenda);
agenda.on('ready', function() {
    agenda.every('5 seconds', 'match providers'); 
    agenda.start();
});

In agenda.js, at line if ( this._mdb.s.topology.connections().length === 0 ), this._mdb is undefined.

The method Agent.prototype.database assigns to _mdb the returned db object from MongoClient.connect. So my guess is that the connect operation fails. Are you sure of your connection string?