useFakeTimers mocha chai sinon - not the right result on a test - mocha.js

Question

I am trying to run a test where I want to verify that my helper file is running correctly, and if I have an expired token, I get an error kickback and cannot proceed.
I have a feeling that I can only fake the time directly in the test, and not outside of it. Thing is, I don't want to copy the jwt.verify function in my test because that defeats the purpose if I change the code in the actual helper file. Any help on this one to make this work?
I am faking the time with sinon. If I test to see what time I get now and after the clock tick, I do get the right results. But for some reason this is not applying to the function in another file.
my local.js file
const moment = require('moment');
const jwt = require('jsonwebtoken');
const secret = process.env.TOKEN_SECRET;
function encodeToken(user) {
const playload = {
exp: moment().add(1, 'hours').unix(), // expires the token in an hour
iat: moment().unix(),
sub: user.id
};
return jwt.sign(playload, secret);
}
function decodeToken(token, callback) {
const payload = jwt.verify(token, secret, function (err, decoded) {
const now = moment().unix();
console.log('tim: ' + decoded.exp); //just to see
console.log('now: ' + now); // just to see
if (now > decoded.exp) {
callback('Token has expired.');
}
callback(null, decoded);
});
}
module.exports = {
encodeToken,
decodeToken
};
and my test file:
process.env.NODE_ENV = 'test';
const chai = require('chai');
const should = chai.should();
const sinon = require('sinon');
const localAuth = require('../../src/server/auth/local');
describe('decodeToken()', function () {
var clock;
beforeEach(function () {
clock = sinon.useFakeTimers();
});
afterEach(function () {
clock.restore();
});
it('should return a decoded payload', function (done) {
const token = localAuth.encodeToken({
id: 1
});
should.exist(token);
token.should.be.a('string');
clock.tick(36001000000);
localAuth.decodeToken(token, (err, res) => {
should.exist(err);
res.should.eql('Token has expired.');
done();
});
});
});

Answer 1

JWT checks the expiry and throws error by itself. So we just have to assert from the error message. I have made some changes to the code and made it working.
I tested this as below, (code snippets)
const moment = require('moment');
const jwt = require('jsonwebtoken');
const secret = 'abczzxczxczxc';
function encodeToken(user) {
const payload = {
exp: moment().add(1, 'hours').unix(), // expires the token in an hour
iat: moment().unix(),
sub: user.id
};
const token = jwt.sign(payload, secret);
return token;
}
function decodeToken(token, callback) {
jwt.verify(token, secret, function(err, decoded) {
callback(err, decoded);
});
}
module.exports = {
encodeToken,
decodeToken
};
Tested as below,
process.env.NODE_ENV = 'test';
const chai = require('chai');
const should = chai.should();
const sinon = require('sinon');
const localAuth = require('./');
describe('decodeToken()', function () {
var clock;
beforeEach(function () {
clock = sinon.useFakeTimers();
});
afterEach(function () {
clock.restore();
});
it('should return a decoded payload', function (done) {
const token = localAuth.encodeToken({
id: 1
});
token.should.exist;
token.should.be.a('string');
clock.tick(36001000000);
localAuth.decodeToken(token, (err, res) => {
should.exist(err);
err.message.should.eql('jwt expired');
done();
});
});
});
Output
➜ faketimer ./node_modules/mocha/bin/mocha index_test.js
decodeToken()
✓ should return a decoded payload
1 passing (17ms)