Waleed Ashraf WaleedAshraf

How to mock express session?

sinon is being used to mock methods in tests. It is one of the most used package for testing. But Is there a way to mock session objects in tests for express?

I'm working on a project where I upload images to s3 in bulk (albums) and than further apply some processing like resizing/compression/editing on them.

It's a express app with middlewares for authorization, authentication, setting context and is working fine. Recently I started adding testcases for different routes using mocha. I'm using cookie-session for session handling in app.

For one route, I needed to mock req.session object. (Need to set it's value before calling the other route.)

	exports.create = function(req, res) {
	// upload image to s3
	var photos = PhotosTable.create(req.files.names); // add entries in database
	req.session.count = photos.length; // set count in req.session
	res.redirect(`api/image/submit`);
	}

	exports.submit = function(req, res) {
	if (req.session.count && req.session.count > 0) { // get count from req.session
	// perform further tasks
	res.sendStatus(200);
	} else {
	res.sendStatus(400);
	}
	}

	// name = "my-session" -> base64 value of required object (cookie)
	// name.sig = "my-session.sig" -> signed value of cookie using Keygrip

	let cookie = Buffer.from(JSON.stringify({"count":2})).toString('base64'); // base64 converted value of cookie

	let kg = Keygrip(['testKey']) // same key as I'm using in my app
	let hash = kg.sign('my-session=' + cookie);

	await request(app).get('api/image/submit').set("Accept", "text/html")
	.set('cookie', ['my-session=' + cookie + '; ' + 'my-session.sig=' + hash + ';'])

	exports.submit = function(req, res) {
	if(req.session.count && req.session.count > 0) { // true
	//do something
	res.sendStatus(200);
	}
	}

	var cluster = require('cluster');
	const numCPUs = require('os').cpus().length;

	module.exports.create = function(options, callback){

	if (cluster.isMaster) {
	// fork child process for notif/sms/email worker
	global.smsWorker = require('child_process').fork('./smsWorker');
	global.emailWorker = require('child_process').fork('./emailWorker');
	global.notifiWorker = require('child_process').fork('./notifWorker');

	var cluster = require('cluster');
	const numCPUs = require('os').cpus().length;

	module.exports.create = function (options, callback) {

	if (cluster.isMaster) {
	// fork child process for notif/sms/email worker
	global.smsWorker = require('child_process').fork('./smsWorker');
	global.emailWorker = require('child_process').fork('./emailWorker');
	global.notifiWorker = require('child_process').fork('./notifWorker');

	process.on('message', function(data) {
	sendSMS(data); // use twilio or something to send sms
	});

	var pm2Config = {
	"apps": [
	{
	"name": "app",
	"script": "app.js",
	"exec_mode": "cluster_mode",
	"instances": "max"
	},
	{
	"name": "smsWorker",