I want to write some unit-tests for my applicatin, can I somehow "mock" some dependencies used with require('dependencyname')?
You are looking for Proxyquire :)
//file1
var get = require('simple-get');
var assert = require('assert');
module.exports = function fetch (callback) {
get('https://api/users', callback);
};
//test file
var proxyquire = require('proxyquire');
var fakeResponse = {status:200};
var fetch = proxyquire('./get', {
'simple-get': function (url, callback) {
process.nextTick(function () {
callback(null, fakeResponse)
})
}
});
fetch(function (err, res) {
assert(res.statusCode, 200)
});
Straight out of their docs.
yes, for example with jest => https://facebook.github.io/jest/
// require model to be mocked
const Mail = require('models/mail');
describe('test ', () => {
// mock send function
Mail.send = jest.fn(() => Promise.resolve());
// clear mock after each test
afterEach(() => Mail.send.mockClear());
// unmock function
afterAll(() => jest.unmock(Mail.send));
it('', () =>
somefunction().then(() => {
// catch params passed to Mail.send triggered by somefunction()
const param = Mail.send.mock.calls[0][0];
})
);
});
Related
I have some dependency in the tested module.
sendResponse.js:
module.exports = function sendResponse(res, data) {
res.send(data);
};
testedModule.js:
const login = require('.../sendResponse');
exports.postLogin = withServerErrorHandler(async (req, res) => {
const { body } = req;
const { email, password } = body;
const user = await login(email, password);
return sendResponse(res, user);
});
And I want to mock sendResponse module and count its calls.
const testedModule = require('.../testedModule');
jest.mock('.../sendResponse', () => jest.fn());
const sendResponse = require('.../sendResponse');
describe('testedModule', () => {
const res = {
//..
};
const req = {
//..
};
describe('Authentication', () => {
test('should pass', async (done) => {
await testedModule.postLogin(req, res);
expect(sendResponse).toHaveBeenCalledTimes(1);
done();
});
})
});
Unfortunately, Jest always gives me that result, It looks like Jest jest spy on jest.fn() function, not specific ref. How can I deal with it?
expect(jest.fn()).toHaveBeenCalledTimes(expected)
Expected number of calls: 1
Received number of calls: 0
My NodeJS application has to do some API requests, so I'm mocking their return as my tests are just for my application's business logic. However, there's two things that I quite didn't understand.
I'm using jest's mockImplementation method to change the return of my service, but I can't make it work without calling jest.mock with the service beforehand.
Also, if I try to set automock: true in my jest.config.js, it returns me an error:|
TypeError: Cannot set property 'gracefulify' of undefined
Here's my test.js code in where I'm testing a function that calls automation.js, which has my application logic and make the calls for my services:
const automation = require('../automations/fake.automation');
// MOCKS
const mockedBlingProduct = require('../mocks/bling-product.mocks.json');
const mockedShopifyCreatedProduct = require('../mocks/shopify-created-product.mocks.json');
// SERVICES
const BlingProductService = require('../services/bling-product.service');
const ShopifyProductService = require('../services/shopify-product.service');
jest.mock('../services/bling-product.service');
jest.mock('../services/shopify-product.service');
describe('Automation test', () => {
beforeEach(() => {
const blingMockedReturn = jest.fn(() => {
return mockedBlingProduct;
});
const shopifyMockedReturn = jest.fn(() => {
return mockedShopifyCreatedProduct;
});
BlingProductService.mockImplementation(() => {
return {
list: blingMockedReturn
};
});
ShopifyProductService.mockImplementation(() => {
return {
create: shopifyMockedReturn
};
});
});
it('should return status SUCCESS', async () => {
const result = await
.run();
expect(result).toEqual({ status: 'SUCCESS' });
});
});
And here's the code of one of my services, keep in mind that the logic behind the API calls is abstracted from the service. In the mockImplementation I'm trying to overwrite the list and create functions inside them:
class BlingPriceService {
async list(query = {}) {
const httpMethod = 'GET';
const resource = 'produtos/page={pageNumber}/json';
const options = {
queryString: query,
urlParams: {
pageNumber: 1,
}
};
return blingComponent.request(httpMethod, resource, options);
}
}
module.exports = BlingPriceService;
const automation = require('../automations/fake.automation');
// MOCKS
const mockedBlingProduct = require('../mocks/bling-product.mocks.json');
const mockedShopifyCreatedProduct = require('../mocks/shopify-created-product.mocks.json');
// SERVICES
const BlingProductService = require('../services/bling-product.service');
const ShopifyProductService = require('../services/shopify-product.service');
describe('Automation test', () => {
beforeAll(() => {
jest.spyOn(BlingProductService.prototype, 'list').mockImplementation(() => Promise.resolve(mockedBlingProduct));
jest.spyOn(ShopifyProductService.prototype, 'list').mockImplementation(() => Promise.resolve(mockedShopifyCreatedProduct));
});
afterAll(() => {
jest.restoreAllMocks();
});
it('should return status SUCCESS', async () => {
const result = await automation.run();
expect(result).toEqual({ status: 'SUCCESS' });
});
});
I have been trying this for a while and i couldn't find the solution.
I tried a lot of solutions (__ mock __ folder, mockimplementation, mock and more) but i always had the same error client.mockImplementation is not a function
//restclient.js
module.exports = (cfg) => new Client(config);
// api.js
const client = require('restclient');
module.exports.doRequest = () => {
const request = client();
const config = {};
request.get('/path/to/request', config)
.then(result => console.log(result))
}
//api.tests.js
const client = require('restclient');
const api = require('./api');
jest.mock('restclient', () => () => ({
get: jest.fn(),
}));
describe('testing API', () => {
test('test then', async () => {
try {
restclient.mockImplementation(() => () => ({
get: (url, config) => 'Hi! I\'m mocked',
}));
const result = await api.doRequest();
console.log('result', result);
} catch (e) {
console.log('eee', e);
}
});
});
I could not found the solution, I think I can't mock the const request = restclient() part but i dont know why!!
You were missing to mock the constructor.
This mocks the constructor of restclient
jest.mock('restclient', ()=> jest.fn().mockImplementation(() => {
/** here you can create and return a mock of request **/
}));
I'm currently making a small server in JavaScript and as part of the learning process I'm writing unit tests for the functions. Unfortunately I ran into major difficulties with a certain test that handles a promise. Below is the router module, with a separate handlePUT function for ease of testing.
const express = require('express');
const service = require('../service/user.service');
const dutyStatusRouter = express.Router();
const output = console;
function handlePUT(req, res) {
service.updateUserStatus()
.then((fulfilled) => {
res.status(fulfilled);
res.send();
})
.catch(() => {
res.status(500);
res.send();
});
}
dutyStatusRouter.route('/').put(handlePUT);
The updateUserStatus function basically toggles a Boolean in a database and looks somewhat like this:
function updateUserStatus() {
return new Promise((resolve, reject) => {
if (…) {
resolve(201);
} else if (…) {
resolve(200);
} else {
reject();
}
});
}
As for the unit tests, I'm using mocha/chai, with proxyquire to create a mock updateUserStatus.
const chai = require('chai');
const sinon = require('sinon');
const proxyquire = require('proxyquire');
const serviceStub = {};
describe('=== Unit test ===', () => {
it('Handle PUT test: promise kept', async () => {
const dutyStatusRouter = proxyquire('../../router/duty-status.router', {
'../service/user.service': serviceStub,
});
serviceStub.updateUserStatus = () => {
return new Promise((resolve, reject) => {
resolve(200);
});
};
const res = {
status: sinon.fake(),
send: sinon.fake(),
};
await dutyStatusRouter.handlePUT({}, res);
chai.assert(res.status.calledOnceWith(200));
});
});
Whenever I try to run the unit test, I get the error Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.. If I try to add done() it still fails by giving the error message Error: Resolution method is overspecified. Specify a callback *or* return a Promise; not both.
Found a solution that works, so I'm adding it here:
const chai = require('chai');
const sinon = require('sinon');
const proxyquire = require('proxyquire');
const serviceStub = {};
const dutyStatusRouter = proxyquire('../../router/duty-status.router', {
'../service/user.service': serviceStub,
});
describe('=== Unit test ===', () => {
it('Handle PUT test: promise kept', (done) => {
serviceStub.updateUserStatus = sinon.stub().resolves(200);
const res = {
status: sinon.fake(),
send: sinon.fake(),
};
dutyStatusRouter.handlePUT({}, res).then(() => {
chai.assert(res.status.calledWith(200));
done();
});
});
});
Note: I changed the handlePUT function just a bit, it now looks like this (I just added a return):
function handlePUT(req, res) {
return service.updateUserStatus()
.then((fulfilled) => {
output.log('Promise fulfilled');
res.status(fulfilled);
res.send();
})
.catch(() => {
output.log('Promise unfulfilled');
res.status(500);
res.send();
});
}
I build express app, there is a route A use many middlewares:
// fblogin.js
const saveUser = require('./middlewares').saveUser;
const issueJWT = require('./middlewares').issueJWT;
const exchangeLongTimeToken = (a) => { //return promise to call API };
const retrieveUserInfo = (b) => { //return promise to call API };
const service = {
exchangeLongTimeToken,
retrieveUserInfo,
};
const asyncAll = (req, res) => {
// use Promise.all() to get service.exchangeLongTimeToken
// and service.retrieveUserInfo
};
router.post('/', [asyncAll, saveUser, issueJWT], (req, res) => {
//some logic;
});
module.exports = { router, service };
And this is my middlewares.js:
const saveUser = (req, res, next) => { //save user };
const issueJWT = (req, res, next) => { //issue jwt };
module.exports = { saveUser, issueJWT };
It works well. But got problem when I tried to write the test.
This is my test, I use mocha, chai, supertest and sinon:
const sinon = require('sinon');
const middlewares = require('../../../../src/routes/api/auth/shared/middlewares');
const testData = require('../../testdata/data.json');
let app = require('../../../../src/config/expressapp').setupApp();
const request = require('supertest');
let service = require('../../../../src/routes/api/auth/facebook/fblogin').service;
describe('I want to test', () => {
context('Let me test', function () {
const testReq = {name: 'verySad'};
beforeEach(() => {
sinon.stub(middlewares, 'saveUser').callsFake((req, res, next)=>{
console.log(req);
});
sinon.stub(service, 'exchangeLongTimeToken').callsFake((url) => {
return Promise.resolve(testData.fbLongTimeToken);
});
sinon.stub(service, 'retrieveUserInfo').callsFake((url) => {
return Promise.resolve(testData.fbUserInfo);
});
});
it('Should return 400 when bad signedRequest', () => {
return request(app).post(facebookAPI).send(testReq).then((response) => {
response.status.should.be.equal(400);
});
});
});
What is the problem
You could see that there are 3 stubs, 1 for middlewares.saveUser and 2 for services.XXXX which is in the same file of the route.
The problem is that, the 2 stubs works while the 1 for middlewares.saveUser not work, always trigger the original one.
I think it maybe that when I call the setupApp(), the express will load all the routers it needs, so mock it afterwards won't have a effect, but it
is strange that route.service could be mocked...
How to get the stub work?
The only way to get it work, is to put the stub at the top of test file, just after that middleware require.
I tried:
1. Use 3rd party modules like proxyquire, rewire
2. Use node's own delete require.cache[middlewares] and 'app' and re-require them.
3. Many other tricks.
4. Use jest's mock, but still only works if I put it at the top of the file.
What is the way of solving this problem without putting the stub at the top of the test file? Thanks!
The solution in the question is a bit restricted, since the mock has polluted the whole test suites.
I end up by doing this, The logic is simple, we still need to mock the saveUser first, but then we require all the other variables into the test function rather than require them at the top of the file, more flexible this time. And I add a checkIfTheStubWorks method to check if the stub works, to make sure the whole test works.
const middlewares = require('../../../../src/routes/api/auth/shared/middlewares');
const removeEmptyProperty = require('../../../../src/utils/utils').removeEmptyProperty;
let app;
let service;
let request;
/*
* The reason we need this is:
* If the mock not works,
* the whole test is meaningless
*/
const checkIfTheStubWorks = () => {
expect(spy1).toHaveBeenCalled();
expect(spy2).toHaveBeenCalled();
expect(spy3).toHaveBeenCalled();
};
const loadAllModules = () => {
service = require('../../../../src/routes/api/auth/facebook/fblogin').service;
app = require('../../../../src/config/expressapp').setupApp();
request = require('supertest')(app);
};
describe('Mock response from facebook', () => {
let spy1 = {};
let spy2 = {};
let spy3 = {};
const testReq = testData.fbShortToken;
beforeAll(() => {
spy1 = jest.spyOn(middlewares, 'saveUser').mockImplementation((req, res, next) => {
userToSaveOrUpdate = removeEmptyProperty(res.locals.user);
next();
});
// It must be load here, in this order,
// otherwise, the above mock won't work!
loadAllModules();
spy2 = jest.spyOn(service, 'exchangeLongTimeToken').mockImplementation((url) => {
// mock it
});
spy3 = jest.spyOn(service, 'retrieveUserInfo').mockImplementation((url) => {
// mock it
});
});
afterAll(() => {
spy1.mockRestore();
spy2.mockRestore();
spy3.mockRestore();
});
test('Return a JWT should have same length as facebook one', async () => {
const response = await request.post(facebookAPI).send(testReq);
// assert this, assert that
checkIfTheStubWorks();
});
});