How to mock Express response object in Node tests using Mocha - node.js

Question

I need to test a function that requires the response as argument, I'm using mocha and sequelize in node environment with express framework. My code is scaffolded in multiple files, but I need to test only the superactivator istance. These are my files:
route.js
const express = require('express');
const router = express.Router();
const rcv_pcController = require('../controllers/rcv_pc.controller');
router.post('/', rcv_pcController.switchMode);
module.exports = router;
rcv_pc.controller.js
const superActivator = require('../helpers/superactivator');
...
const switchMode = async (req, res) => {
...
switch (tipo) {
case "1":
{
if (modo == "1") {
superActivator.checkLicense(license, hwId, oem, expire, nowDate, ip, allowedSerials, res)
}
else if (modo == "2") {
superActivator.generateLicense(license, hwId, reqCode, nowDate, ip, res);
}
else if (modo == "3") {
superActivator.registerLicense(license, hwId, reqCode, nowDate, customerName, referenteName, referentePhone, ip, res)
}
break;
}
}
}
module.exports.switchMode = switchMode;
superactivator.js
const pcRepo = require("../repositories/pc.server.repository");
const repository = require('../repositories/rcvpc.server.repository');
...
class SuperActivator {
...
checkLicense(license, hwId, oem, expDate, nowDate, ip, allowedSerials, res) {
repository.findLicense(license).then(key => {
// console.log(key[0]);
if (key[0]) {
if (!isset(key[0]['SS_ALLOWED_SERIALS']) || is_null(key[0]['SS_ALLOWED_SERIALS'])) {
key[0]['SS_ALLOWED_SERIALS'] = "";
}
if (this.updatePcRx(hwId, ip, nowDate) == 0) {
return res.send(this.licCheckResult.server_error);
}
if (this.checksetBanned(hwId) == 0) {
return res.send(this.licCheckResult.hwid_banned);
}
if (!isset(key[0]['SP_HW_ID'])) {
return res.send(this.licCheckResult.key_virgin);
}
if (key[0]['SS_STATUS'] < 1) {
return res.send(this.licCheckResult.key_unallowed);
}
if (key[0]['SP_HW_ID'] != hwId) {
if (this.setKeyMismatched(key[0]['SS_ID']) == 1) {
return res.send(this.licCheckResult.key_moved);
}
}
if ((strtotime(key[0]['SS_EXPIRE']) < strtotime(expDate))
|| (strtotime(nowDate) < strtotime(key[0]['SP_PC_DATE_TIME']))
|| (strtotime(nowDate) < time() - 60 * 60 * 24 * 2)) {
if (this.setKeyMismatched(key[0]['SS_ID']) == 1) {
return res.send(this.licCheckResult.dates_hacked);
} else {
return res.send(this.licCheckResult.server_error);
}
}
if ((key[0]['SS_OEM'] != oem)
|| (strtotime(key[0]['SS_EXPIRE']) > strtotime(expDate) || strcmp(key[0]['SS_ALLOWED_SERIALS'], this.decodeToMortal(allowedSerials)) != 0)) {
return res.send(this.licCheckResult.key_info_to_update);
}
if (strtotime(key[0]['SS_EXPIRE']) <= strtotime(nowDate)) {
return res.send(this.licCheckResult.key_expired);
}
return res.send(this.licCheckResult.key_ok);
} else {
return res.send(this.licCheckResult.key_insesistente);
}
}).catch(err => res.send(err.errors));
}
generateLicense(license, hwId, reqCode, nowDate, ip, res) {
pcRepo.updatePcRx(hwId, ip, nowDate);
repository.findOem(license, hwId)
.then((foundOem) => {
if (foundOem[0]) {
const keyCode = this.generateValidKey(this.decodeToMortal(reqCode));
let patchKey = keyCode;
if (keyCode.length != 10 || this.checkValidKey(keyCode, patchKey) == 'KO') {
return res.send(this.licCheckResult.invalid_reqcode);
} else {
let oem = '';
switch (foundOem[0]['SS_OEM']) {
case 0:
oem = 'thisisnotoem'
break;
case 1:
oem = 'thisisoem'
break;
case 2:
oem = 'thisisoemdoc'
break;
case 3:
oem = 'thisislock'
break;
case 10:
oem = 'thisisnotoem_lecu'
break;
case 11:
oem = 'thisisdemo_lecu'
break;
case 12:
oem = 'thisisoem_lecu'
break;
}
const keepDate = str_replace('-', "", foundOem[0]['SS_EXPIRE'])
const allowedSerials = this.getAllowedSerials(foundOem[0]['SS_ID'])
console.log(allowedSerials);
const key =
this.codeToGod(keyCode) + '|'
+ this.codeToGod(patchKey) + '|'
+ this.codeToGod(oem) + '|'
+ this.codeToGod(keepDate) + '|'
+ this.codeToGod(allowedSerials);
// console.log(key);
return res.send(key);
}
} else {
return res.send(this.licCheckResult.key_insesistente);
}
}).catch(err => res.send(err.errors));
}
registerLicense(license, hwId, reqKey, pcDate, customerName, referenteName, referentePhone, ip, res) {
pcRepo.findOne(hwId)
.then((pc) => {
let pcId = '';
if (!pc) {
const data = {
SP_HW_ID: hwId,
SP_LAST_RX: Date.now(),
SP_IP: ip,
SP_PC_DATE_TIME: new Date().toISOString().slice(0, 10)
}
pcRepo.create(data)
.then((newPc) => {
if (!newPc) {
return res.send(this.licCheckResult.server_error);
}
return pcId = newPc['SP_ID']
}).catch(err => res.send(err.errors));
} else {
pcId = pc['SP_ID']
}
console.log(pcId);
if (isset(pcId) || pcId.length == 0 || pcId == 0) {
return res.send(this.licCheckResult.server_error);
}
repository.updateLicense(pcId, customerName, referenteName, referentePhone, license)
.spread((results, metadata) => {
if (!results) {
return res.send(this.licCheckResult.server_error);
}
return this.generateLicense(license, hwId, reqKey, pcDate, ip, res);
}).catch(err => res.send(err.errors))
}).catch(err => res.send(err.errors));
}
}
...
const superActivator = new SuperActivator(licCheckResult);
module.exports = superActivator;
For the sake of clarity I omit all the Superactivator class methods. This is my test code:
superactivator.spec.js
...
const superactivator = require('../helpers/superactivator');
...
describe('checkLicense()', function () {
it('sks ', async function () {
// here I mock the request.body data
const ip = '127.0.0.1';
const license = "A2YyLM8i3G7feJt7Hlm8hxlYk";
const hwId = "123490EN40";
const oem = 12;
const expDate = "2019-10-10";
const nowDate = null; // "2018-09-05"
const allowedSerials = null;
const foundSks = await superactivator.checkLicensecheckLicense(license, hwId, oem, expDate, nowDate, ip, allowedSerials, res)
assert.equal(foundSks, '1');
});
});
I get the error
ReferenceError: res is not defined
at Context. (test\superactivator.spec.js:23:130)
because I do not have res in test files. How can I solve this problem? I need to simply mock the response to check the returned values.
Thanks for help!

Answer 1

Maybe for someone this quick solution will be helpful:
import { Response } from 'express';
const mockedResponse = {
// mock props, methods you use
setHeader: jest.fn(),
} as unknown as Response;

Answer 2

You can use Sinon to help you spy/stub res from express ie:
...
const superactivator = require('../helpers/superactivator');
const sinon = require('sinon'); // ----> use sinon
...
describe('checkLicense()', function () {
it('sks ', async function () {
// here I mock the request.body data
const ip = '127.0.0.1';
const license = "A2YyLM8i3G7feJt7Hlm8hxlYk";
const hwId = "123490EN40";
const oem = 12;
const expDate = "2019-10-10";
const nowDate = null; // "2018-09-05"
const allowedSerials = null;
const res = {
send: sinon.spy() // --> create spy for res.send method
}
const foundSks = await superactivator.checkLicensecheckLicense(license, hwId, oem, expDate, nowDate, ip, allowedSerials, res)
assert.equal(foundSks, '1');
});
});
Ref:
https://sinonjs.org/releases/v6.2.0/spies/