We Keep Coding

How to stub a dependency in express middleware (express-validator/mocha/chai/sinon/proxyquire)

**Edit: Re-written with a simple example that works first:
So I've got a test file and 2 modules.
moduleA has a dependency, moduleB
// moduleA.js
const ModuleB = require('./moduleB');
function functionA() {
return 20 + ModuleB.functionB();
};
module.exports = { functionA };
// moduleB.js
const functionB = () => {
return 10;
}
module.exports = { functionB }
My test file stubs out functionB (returned from moduleB) using proxyquire:
const sinon = require('sinon');
const proxyquire = require('proxyquire');
describe('Unit Tests', function() {
it('should work', () => {
const mockedFn = sinon.stub();
mockedFn.returns(30);
const copyModuleA = proxyquire('./moduleA', {
'./moduleB': {
functionB: mockedFn
}
});
console.log(copyModuleA.functionA());
})
});
So it outputs 50 (stubbed functionB 30 + functionA 20)
Now I'm trying to take this example into my code:
moduleA in this case is a file called validation.js. It is dependent on moduleB, in this case a sequelize model, Person, with the function I want to mock: findOne
validation.js exports module.exports = { validateLogin };, a function that calls validate, which returns a function that uses Person.findOne()
So in my mind, as with the simple example, I need to create a stub, point to the validation module in proxyquire, and reference the dependency and its findOne function. Like this:
const stubbedFindOne = sinon.stub();
stubbedFindOne.resolves();
validationModule = proxyquire('../../utils/validation', {
'../models/Person': {
findOne: stubbedFindOne
}
});
This should stub Person.findOne in validation.js. But it doesn't seem to. And I have no idea why.
let validationModule;
describe('Unit Tests', () => {
before(() => {
const stubbedFindOne = sinon.stub();
stubbedFindOne.resolves();
validationModule = proxyquire('../../utils/validation', {
'../models/Person': {
findOne: stubbedFindOne
}
});
})
it.only('should return 422 if custom email validation fails', async() => {
const wrongEmailReq = { body: {email: 'nik#hotmail.com'} };
const res = {
statusCode: 500,
status: (code) => {this.statusCode = code; return this},
};
const validationFn = validationModule.validateLogin();
const wrongEmail = await validationFn(wrongEmailReq, res, ()=>{});
expect(wrongEmail.errors[0].msg).to.be.equal('Custom Authorisation Error');
return;
})
And this is my validation.js file:
const Person = require('../models/Person');
// parallel processing
const validate = validations => {
return async (req, res, next) => {
await Promise.all(validations.map(validation => validation.run(req)));
const errors = validationResult(req);
if (errors.isEmpty()) {
return next();
}
const error = new Error();
error.message = process.env.NODE_ENV === 'development'? 'Validation Failed':'Error';
error.statusCode = !errors.isEmpty()? 422:500;
error.errors = errors.array({onlyFirstError: true});
next(error);
return error;
};
};
const validateLogin = () => {
const validations = [
body('email')
.isString()
// snip
.custom(async (value, {req}) => {
try{
const person = await Person.findOne({ where: { email: value } });
if(!person) return Promise.reject('Custom Authorisation Error');
} catch(err) {
throw err;
}
})
.trim(),
];
return validate(validations);
}
module.exports = {
validateLogin
};

So the code in both the small sample and my app is correct, apart from how I stub the function. It shouldn't resolve or reject anything (I tried both out of desperation). It should return null in order to satisfy the conditional rather than jump to the catch block:
try{
const person = await Person.findOne({ where: { email: value } });
if(!person) return Promise.reject('Custom Authorisation Error');
} catch(err) {
throw err;
}
Hope the simple example helps someone else with proxyquire though

Testing controller with Jest - trying to inject a service to it with no luck

I'm new to testing in nodejs, I have an express backend split into microservices, and I'm currently trying to test the controller in the User directory.
The controller has a constructor which gets the user service - which is in charge of making DB operations. It's injected usually with awilix. I've been trying to inject my own mock object, but with no luck.
Here's what my userController.test.js looks like:
const request = require('supertest')
const UserController = require('../controllers/userController.js');
const { mockRequest, mockResponse } = require('../utils/interceptor')
const getAllUsers = jest.fn();
const userLogIn = jest.fn();
const getUserById = jest.fn();
const getUserByEmail = jest.fn();
const SearchUsers = jest.fn();
const changePassword = jest.fn();
const ChangeUserPicture = jest.fn();
const addUser = jest.fn();
getUserById.mockReturnValue({
id: 1,
name: 'user',
email: 'user#example.com'
})
userController = new UserController({
getAllUsers,
userLogIn,
getUserById,
getUserByEmail,
SearchUsers,
changePassword,
ChangeUserPicture,
addUser
});
describe('getuserbyid', () => {
test('should fetch a user by id', async () => {
let req = mockRequest();
req.params.id = 1;
const res = mockResponse();
await userController.getUserById(req, res)
.then((res) => console.log(res))
expect(res.mock).toBe({
name: 'user',
email: 'user#example.com'
});
expect(res.mock.calls.length).toBe(1);
})
})
As you can see, I'm passing in my own new object to the UserController constructor, yet when running the tests, I get that it's undefined.
Here's how it looks like in the controller:
async getUserById(req, res) {
try {
return JSON.stringify(await this.userService.getUserById(req));
}
catch (error) {
console.log(`There Was a Problem Getting User. error: ${error.message}`);
return (`Failed to get user, error: ${error.message}`);
}
}
I just get
Failed to get user, error: Cannot read property 'getUserById' of undefined

google-calendar sinon stub doesn't seem to work

In my calendar.spec.js, I have:
const { google } = require('googleapis')
const googleCalendar = google.calendar('v3')
...
before(() => {
sinon.stub(googleCalendar.calendarList, 'list').resolves({ data: true })
})
after(() => {
googleCalendar.calendarList.list.restore()
})
In my calendar.js, I have:
const { google } = require('googleapis')
const googleCalendar = google.calendar('v3')
let { data } = await googleCalendar.calendarList.list({
auth: oauth2Client
})
But it doesn't appear to be stubbed. It goes ahead and tries to connect to Google Calendar. What am I doing wrong?

You can mock the entire googleapis module with mock-require.
const mock = require('mock-require');
mock('googleapis', {
google: {
calendar: () => ({
calendarList: {
list: () => {
return Promise.resolve({
data: {
foo: 'bar'
}
});
}
}
})
}
});
Once you mocked it, your module will consume the mocked module instead of the original so you can test it. So if you module is exposing a method that calls the API, something like that:
exports.init = async () => {
const { google } = require('googleapis');
const googleCalendar = google.calendar('v3');
let { data } = await googleCalendar.calendarList.list({
auth: 'auth'
});
return data;
}
The test will be
describe('test', () => {
it('should call the api and console the output', async () => {
const result = await init();
assert.isTrue(result.foo === 'bar');
});
});
Here is a small repo to play with it: https://github.com/moshfeu/mock-google-apis

Stubbing auth0 in firebase functions

I have the following Firebase Function that makes use of Auth0 to get a user profile.
'use strict';
const {
dialogflow,
Image,
} = require('actions-on-google')
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
const db = admin.firestore();
// database collection and key names
const DB_BANK_COLLECTION_KEY = 'bank'
// the action name from all Dialogflow intents
const INTENT_WELCOME_USER = 'Default Welcome Intent';
// Initialize the Auth0 client
var AuthenticationClient = require('auth0').AuthenticationClient;
var auth0 = new AuthenticationClient({
domain: functions.config().familybank.auth0.domain,
clientID: functions.config().familybank.auth0.clientid
});
const app = dialogflow();
app.intent(INTENT_WELCOME_USER, async (conv) => {
console.log('Request: ' + JSON.stringify(conv.request));
const userInfo = await auth0.getProfile(conv.user.access.token)
.catch( function(err) {
console.error('Error getting userProfile from Auth0: ' + err);
conv.close("Something went wrong. Please try again in a few minutes. " + err)
});
console.log('userInfo: ' + JSON.stringify(userInfo));
// check for existing bank, if not present, create it
var bankRef = db.collection(DB_BANK_COLLECTION_KEY).doc(userInfo.email);
const bankSnapshot = await bankRef.get()
})
exports.accessAccount = functions.https.onRequest(app);
I tried to mock auth0 in my tests using the following code (and several permutations), but the actual function always gets called instead of the mock.
const chai = require('chai');
const assert = chai.assert;
const sinon = require('sinon');
// Require firebase-admin so we can stub out some of its methods.
const admin = require('firebase-admin');
const test = require('firebase-functions-test')();
var AuthenticationClient = require('auth0').AuthenticationClient;
var auth0 = new AuthenticationClient({
domain: "mock",
clientID: "mock"
});
describe('Cloud Functions', () => {
let myFunctions, adminInitStub;
before(() => {
test.mockConfig({"familybank": {"auth0": {"domain": "mockdomain", "clientid": "mockid"}}});
adminInitStub = sinon.stub(admin, 'initializeApp');
sinon.stub(admin, 'firestore')
.get(function() {
return function() {
return "data";
}
});
sinon.stub(auth0, 'getProfile').callsFake( function fakeGetProfile(accessToken) {
return Promise.resolve({"email": "daniel.watrous#gmail.com", "accessToken": accessToken});
});
myFunctions = require('../index');
});
after(() => {
adminInitStub.restore();
test.cleanup();
});
describe('accessAccount', () => {
it('should return a 200', (done) => {
const req = {REQUESTDATA};
const res = {
redirect: (code, url) => {
assert.equal(code, 200);
done();
}
};
myFunctions.accessAccount(req, res);
});
});
})
Is there some way to mock auth0 for my offline tests?

I discovered that rather than initialize the Auth0 AuthenticationClient, I could first require the UsersManager, where the getProfile (which wraps getInfo) is defined.
var UsersManager = require('auth0/src/auth/UsersManager');
In my before() method, I can then create a stub for getInfo, like this
sinon.stub(UsersManager.prototype, 'getInfo').callsFake( function fakeGetProfile() {
return Promise.resolve({"email": "some.user#company.com"});
});
All the calls to auth0.getProfile then return a Promise that resolves to the document shown in my stub fake function.

How to mock a function in another function nodejs

Trying to write a unittest for the below module in /utility/sqsThing.js. However I'm having diffuculty mocking the sqs.sendMessage method. Anyone know how I should go about this. I'm using the sinon library, and mocha for running the tests.
The function that I'm trying to unittest utility/sqsThing.js:
const AWS = require('aws-sdk');
AWS.config.update({ region: 'us-east-1' });
const sqs = new AWS.SQS({ apiVersion: '2012-11-05' });
const outputQueURL = 'https:awsUrl';
const SQSOutputSender = (results) => {
const params = {
MessageBody: JSON.stringify(results),
QueueUrl: outputQueURL,
};
// Method that I want to mock
sqs.sendMessage(params, function (err, data) {
if (err) {
console.log('Error');
} else {
console.log('Success', data.MessageId);
}
});
};
My attempt at mocking the sqs.sendMessage method in a unittest sqsThingTest.js:
const sqsOutputResultSender = require('../utility/sqsThing');
const AWS = require('aws-sdk');
const sqs = new AWS.SQS({ apiVersion: '2012-11-05' });
const mochaccino = require('mochaccino');
const { expect } = mochaccino;
const sinon = require('sinon');
describe('SQS thing test', function() {
beforeEach(function () {
sinon.stub(sqs, 'sendMessage').callsFake( function() { return 'test' });
});
afterEach(function () {
sqs.sendMessage.restore();
});
it('sqsOutputResultSender.SQSOutputSender', function() {
// Where the mock substitution should occur
const a = sqsOutputResultSender.SQSOutputSender('a');
expect(a).toEqual('test');
})
});
Running this unittest with mocha tests/unit/sqsThingTest.js however I get:
AssertionError: expected undefined to deeply equal 'test'.
info: Error AccessDenied: Access to the resource https://sqs.us-east-1.amazonaws.com/ is denied..
It looks like the mock did not replace the aws api call. Anyone know how I can mock sqs.SendMessage in my test?

You could use rewire js it is a library that lets you inject mocked properties into your module you want to test.
Your require statement would look something like this:
var rewire = require("rewire");
var sqsOutputResultSender = rewire('../utility/sqsThing');
Rewire will allow you to mock everything in the top-level scope of you sqsThing.js file.
Also you need to return the value of sqs.sendMessage this will remove the issue expected undefined to deeply equal 'test'
Your original file would look the same just with a return statement.
//utility/sqsThing.js
const AWS = require('aws-sdk');
AWS.config.update({ region: 'us-east-1' });
const sqs = new AWS.SQS({ apiVersion: '2012-11-05' });
const outputQueURL = 'https:awsUrl';
const SQSOutputSender = (results) => {
const params = {
MessageBody: JSON.stringify(results),
QueueUrl: outputQueURL,
};
// Method that I want to mock
return sqs.sendMessage(params, function (err, data) {
if (err) {
console.log('Error');
} else {
console.log('Success', data.MessageId);
}
});
};
You would then write your unit test as follows:
//sqsThingTest.js
var rewire = require("rewire");
var sqsOutputResultSender = rewire('../utility/sqsThing');
const mochaccino = require('mochaccino');
const { expect } = mochaccino;
const sinon = require('sinon');
describe('SQS thing test', function() {
beforeEach(function () {
sqsOutputResultSender.__set__("sqs", {
sendMessage: function() { return 'test' }
});
});
it('sqsOutputResultSender.SQSOutputSender', function() {
// Where the mock substitution should occur
const a = sqsOutputResultSender.SQSOutputSender('a');
expect(a).toEqual('test');
})
});
This example returns an object with a property of sendMessage but this could be replaces with a spy.
Rewire Docs

Try moving the declaration of sqsOutputResultSender after you have stubbed the sendmessage function
var sqsOutputResultSender;
const AWS = require('aws-sdk');
const sqs = new AWS.SQS({ apiVersion: '2012-11-05' });
const mochaccino = require('mochaccino');
const { expect } = mochaccino;
const sinon = require('sinon');
describe('SQS thing test', function() {
beforeEach(function () {
sinon.stub(sqs, 'sendMessage').callsFake( function() { return 'test' });
sqsOutputResultSender = require('../utility/sqsThing');
});
afterEach(function () {
sqs.sendMessage.restore();
});
it('sqsOutputResultSender.SQSOutputSender', function() {
// Where the mock substitution should occur
const a = sqsOutputResultSender.SQSOutputSender('a');
expect(a).toEqual('test');
})
});