jest + supertest: how to reset the mocked dependency - javascript

I am not able to reset jest mocks of a dependency after it's being used once by supertest. I appreciate any help or hint.
The following is my api test with supertest:
import request from 'supertest';
import router from '../index';
const app = require('express')();
app.use(router);
jest.mock('config', () => ({}));
jest.mock('express-request-proxy', () => data => (req, res, next) =>
res.json(data),
);
beforeEach(() => {
jest.resetAllMocks();
});
describe('GET /', () => {
it('should get all stuff', () =>
request(app)
.get('')
.expect(200)
.expect('Content-Type', /json/)
.then(response => {
expect(response.body).toMatchSnapshot(); // all good here
}));
it('should get all stuff when FOO=bar', async () => {
jest.mock('config', () => ({
FOO: 'bar',
get: key => key,
}));
// >> HERE <<
// config.FOO is still undefined!
// reseting mocks did not work ...
await request(app)
.get('')
.expect(200)
.expect('Content-Type', /json/)
.then(response => {
expect(response.body.query).toHaveProperty('baz'); // test fails ...
});
});
});
express.js api:
const router = require('express').Router({ mergeParams: true });
import config from 'config';
import proxy from 'express-request-proxy';
router.get('', (...args) => {
let query = {};
if (config.FOO === 'bar') {
query.baz = true;
}
return proxy({
url: '/stuff',
query,
})(...args);
});

You can't use jest.mock(moduleName, factory, options) in a function scope, it should be used in the module scope. You should use jest.doMock(moduleName, factory, options) if you want to arrange the mocks in function scope of test cases.
We also need to use jest.resetModules() before executing each test case to
reset the module registry - the cache of all required modules.
It means your ./config module registry will be reset so that it will return different mocked values for each test case when you require it after jest.doMock('./config', () => {...}) statement.
{ virtual: true } option means I don't install the express-request-proxy package so it doesn't exist in my npm_modules directory. If you had already installed it, you can remove this option.
Here is the unit test solution:
index.js:
const router = require('express').Router({ mergeParams: true });
import config from './config';
import proxy from 'express-request-proxy';
router.get('', (...args) => {
console.log(config);
let query = {};
if (config.FOO === 'bar') {
query.baz = true;
}
return proxy({ url: '/stuff', query })(...args);
});
export default router;
config.js:
export default {
FOO: '',
};
index.test.js:
import request from 'supertest';
jest.mock('express-request-proxy', () => (data) => (req, res, next) => res.json(data), { virtual: true });
beforeEach(() => {
jest.resetAllMocks();
jest.resetModules();
});
describe('GET /', () => {
it('should get all stuff', () => {
jest.doMock('./config', () => ({}));
const router = require('./index').default;
const app = require('express')();
app.use(router);
return request(app)
.get('')
.expect(200)
.expect('Content-Type', /json/)
.then((response) => {
expect(response.body).toMatchSnapshot();
});
});
it('should get all stuff when FOO=bar', async () => {
jest.doMock('./config', () => ({
default: {
FOO: 'bar',
get: (key) => key,
},
__esModule: true,
}));
const router = require('./index').default;
const app = require('express')();
app.use(router);
await request(app)
.get('')
.expect(200)
.expect('Content-Type', /json/)
.then((response) => {
expect(response.body.query).toHaveProperty('baz');
});
});
});
unit test results with 100% coverage report:
PASS stackoverflow/61828748/index.test.js (11.966s)
GET /
✓ should get all stuff (8710ms)
✓ should get all stuff when FOO=bar (24ms)
console.log
{}
at stackoverflow/61828748/index.js:7:11
console.log
{ FOO: 'bar', get: [Function: get] }
at stackoverflow/61828748/index.js:7:11
----------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
index.js | 100 | 100 | 100 | 100 |
----------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests: 2 passed, 2 total
Snapshots: 1 passed, 1 total
Time: 13.268s
index.test.js.snap:
// Jest Snapshot v1
exports[`GET / should get all stuff 1`] = `
Object {
"query": Object {},
"url": "/stuff",
}
`;
source code: https://github.com/mrdulin/react-apollo-graphql-starter-kit/tree/master/stackoverflow/61828748

Related

Stub of Sinon using axios returns undefined

I'm testing using sinon with axios.
// index.js
{
.. more code
const result = await axios.get("http://save")
const sum = result.data.sum
}
And I made a test code by sinon and supertest for e2e test.
// index.test.js
describe('ADMINS GET API, METHOD: GET', () => {
it('/admins', async () => {
sandbox
.stub(axios, 'get')
.withArgs('http://save')
.resolves({sum: 12});
await supertest(app)
.get('/admins')
.expect(200)
.then(async response => {
expect(response.body.code).toBe(200);
});
});
});
But when I test it, it gives me this result.
// index.js
{
.. more code
const result = await axios.get("http://save")
const sum = result.data.sum
console.log(sum) // undefined
}
I think I resolved response. But it doesnt' give any response.
It just pass axios on supertest.
How can I return correct data in this case?
Thank you for reading it.
The resolved value should be { data: { sum: 12 } }.
E.g.
index.js:
const express = require('express');
const axios = require('axios');
const app = express();
app.get('/admins', async (req, res) => {
const result = await axios.get('http://save');
const sum = result.data.sum;
res.json({ code: 200, sum });
});
module.exports = { app };
index.test.js:
const supertest = require('supertest');
const axios = require('axios');
const sinon = require('sinon');
const { app } = require('./index');
describe('ADMINS GET API, METHOD: GET', () => {
it('/admins', async () => {
const sandbox = sinon.createSandbox();
sandbox
.stub(axios, 'get')
.withArgs('http://save')
.resolves({ data: { sum: 12 } });
await supertest(app)
.get('/admins')
.expect(200)
.then(async (response) => {
sinon.assert.match(response.body.code, 200);
sinon.assert.match(response.body.sum, 12);
});
});
});
test result:
ADMINS GET API, METHOD: GET
✓ /admins
1 passing (22ms)
----------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
index.js | 100 | 100 | 100 | 100 |
----------|---------|----------|---------|---------|-------------------

test rejecting an axios promise

I am trying to figure out how to correctly mock this code. I have figured out how to mock a success, but I cannot figure out how to mock the catch/reject block.
App code:
function getData(url = '') {
return new Promise((resolve, reject) => {
axios
.get(`${baseURL}${url}`)
.then((res) => {
resolve(res.data);
})
.catch((err) => {
reject(err);
});
});
}
in testing I have:
import axios from 'axios';
const MockAdapter = require('axios-moc-adapter');
describe('getData', () => {
it('test success', async () => {
const mock = new MockAdapter(axios);
mock.onGet(`${service.baseURL}/sites`).reply(200, 'success');
const axiosSpy = jest.spyOn(axios, 'get');
const rtn = await service.getData('/sites');
expect(axiosSpy).toHaveBeenCalled();
expect(rtn).toBe('success');
});
it('test failure', async () => {
const mock = new MockAdapter(axios);
mock.onGet(`${service.baseURL}/sites`).networkError();
const rtn = await service.getData('/sites').catch((err) => {
expect(err.message).toBe('message');
});
expect(rtn).toBe(undefined);
});
});
The test success test works, but when I test the failure, I get:
Expected: "message"
Received: "Cannot read properties of undefined (reading 'then')"
29 | mock.onGet(`${service.baseURL}/sites`).networkError();
30 | const rtn = await service.getData('/sites').catch((err) => {
> 31 | expect(err.message).toBe('message');
| ^
32 | });
33 | expect(rtn).toBe(undefined);
34 | });
How can I write a test that successfully passes the failure case? Specifically, I can make this test pass by not checking inside the catch block, but when I run coverage, it doesn't cover the catch block in the App code. How can I correctly cover this line?
Can't reproduce your issue, but .networkError() will throw an error with 'Network Error' message rather than 'message', see source code index.js#L141
service.ts:
import axios from 'axios';
export const baseURL = 'http://localhost:3000/api';
export function getData(url = '') {
return new Promise((resolve, reject) => {
axios
.get(`${baseURL}${url}`)
.then((res) => {
resolve(res.data);
})
.catch((err) => {
reject(err);
});
});
}
service.test.ts:
import * as service from './service';
import axios from 'axios';
import MockAdapter from 'axios-mock-adapter';
describe('getData', () => {
it('test success', async () => {
const mock = new MockAdapter(axios);
mock.onGet(`${service.baseURL}/sites`).reply(200, 'success');
const axiosSpy = jest.spyOn(axios, 'get');
const rtn = await service.getData('/sites');
expect(axiosSpy).toHaveBeenCalled();
expect(rtn).toBe('success');
});
it('test failure', async () => {
const mock = new MockAdapter(axios);
mock.onGet(`${service.baseURL}/sites`).networkError();
const rtn = await service.getData('/sites').catch((err) => {
expect(err.message).toBe('Network Error');
});
expect(rtn).toBe(undefined);
});
it('test failure 2', async () => {
const mock = new MockAdapter(axios);
mock.onGet(`${service.baseURL}/sites`).networkError();
await expect(service.getData('/sites')).rejects.toThrowError('Network Error');
});
});
test result:
PASS examples/69947398/service.test.ts (8.89 s)
getData
✓ test success (5 ms)
✓ test failure (1 ms)
✓ test failure 2 (2 ms)
------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
------------|---------|----------|---------|---------|-------------------
All files | 100 | 0 | 100 | 100 |
service.ts | 100 | 0 | 100 | 100 | 4
------------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests: 3 passed, 3 total
Snapshots: 0 total
Time: 9.52 s

Jest - Create React App - Axios: test get mocked

I have a axiosInstance.js axios instance:
import axios from "axios"
import { REACT_FE_ACCESS_TOKEN } from "../../constants/constant";
const axiosInstance = axios.create({
baseURL: process.env.REACT_APP_BACKEND_URL,
headers: {
"content-type": "application/json"
},
responseType: "json"
});
axiosInstance.interceptors.request.use((config) => {
const token = localStorage.getItem(REACT_FE_ACCESS_TOKEN);
if (token) {
config.headers.Authorization = `Bearer ${token}`;
}
return config;
});
export { axiosInstance };
I call it from a class:
import { axiosInstance as api } from "./axiosInstance";
export default class ApiCrud {
constructor(baseUrl) {
this.baseUrl = baseUrl;
}
fetchItems() {
return api.get(`${this.getBaseUrl()}`).then(result => result.data);
}
getBaseUrl() {
return this.baseUrl;
}
}
I want to do a write test (using Create React App and Jest).
This is the axiosInstance.test.js file, that works:
import { axiosInstance } from "../../../../utils/api/base/axiosInstance";
import { REACT_FE_ACCESS_TOKEN } from "../../../../utils/constants/constant";
const token = "a1.b2.c3";
beforeEach(() => {
localStorage.clear();
});
describe('Test API Instance', () => {
it ('Test request interceptor with token', () => {
localStorage.setItem(REACT_FE_ACCESS_TOKEN, token);
expect(localStorage.getItem(REACT_FE_ACCESS_TOKEN)).toBe(token);
const result = axiosInstance.interceptors.request.handlers[0].fulfilled({ headers: {} });
expect(result.headers).toHaveProperty("Authorization");
});
it ('Test request interceptor without token', () => {
const result = axiosInstance.interceptors.request.handlers[0].fulfilled({ headers: {} });
expect(result.headers).not.toHaveProperty("Authorization");
});
});
This is the apiCrud.test.js
import ApiCrud from "../../../../utils/api/base/ApiCrud";
const mockedGet = {
email: "info#example.com",
}
jest.mock('axios', () => {
return {
create: jest.fn(() => ({
get: jest.fn(() => Promise.resolve({ data: mockedGet })),
interceptors: {
request: { use: jest.fn(), eject: jest.fn() },
response: { use: jest.fn(), eject: jest.fn() }
}
}))
}
})
describe('Test API crud', () => {
it ('Test can get base url', () => {
const apiCrud = new ApiCrud('/fake-url');
expect(apiCrud.getBaseUrl()).toBe('/fake-url');
});
it ('Test can fetch items', () => {
const apiCrud = new ApiCrud('/fake-url');
return apiCrud.fetchItems().then(data => {
expect(data).toBe(mockedGet);
})
});
});
But I get
FAIL src/__tests__/utils/api/base/apiCrud.test.js
● Test API crud › Test can fetch items
TypeError: Cannot read property 'then' of undefined
8 |
9 | fetchItems() {
> 10 | return api.get(`${this.getBaseUrl()}`).then(result => result.data);
| ^
11 | }
12 |
13 | getBaseUrl() {
at ApiCrud.fetchItems (src/utils/api/base/ApiCrud.js:10:12)
at Object.<anonymous> (src/__tests__/utils/api/base/apiCrud.test.js:29:20)
So, I think I'm getting wrong with mocking the get for axios, but... How solve?
You are testing ApiCrud class that depends on the ./axiosInstance module. It's simpler to mock direct dependency ./axiosInstance module than indirect
dependency - axios module.
ApiCrud.js:
import { axiosInstance as api } from './axiosInstance';
export default class ApiCrud {
constructor(baseUrl) {
this.baseUrl = baseUrl;
}
fetchItems() {
return api.get(`${this.getBaseUrl()}`).then((result) => result.data);
}
getBaseUrl() {
return this.baseUrl;
}
}
ApiCrud.test.js:
import ApiCrud from './ApiCrud';
import { axiosInstance } from './axiosInstance';
const mockedGet = {
email: 'info#example.com',
};
jest.mock('./axiosInstance');
describe('Test API crud', () => {
afterEach(() => {
jest.clearAllMocks();
});
afterAll(() => {
jest.resetAllMocks();
});
it('Test can get base url', () => {
const apiCrud = new ApiCrud('/fake-url');
expect(apiCrud.getBaseUrl()).toBe('/fake-url');
});
it('Test can fetch items', () => {
axiosInstance.get.mockResolvedValueOnce({ data: mockedGet });
const apiCrud = new ApiCrud('/fake-url');
return apiCrud.fetchItems().then((data) => {
expect(data).toBe(mockedGet);
});
});
});
test result:
PASS examples/69531160/ApiCrud.test.js (10.676 s)
Test API crud
✓ Test can get base url (3 ms)
✓ Test can fetch items (1 ms)
------------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
------------------|---------|----------|---------|---------|-------------------
All files | 73.33 | 0 | 80 | 71.43 |
ApiCrud.js | 100 | 100 | 100 | 100 |
axiosInstance.js | 55.56 | 0 | 0 | 55.56 | 13-17
------------------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests: 2 passed, 2 total
Snapshots: 0 total
Time: 14.978 s

Jest mock not resolving to each injected value

I'm trying to test a Firebase cloud function named myCloudFn in my functions/send.js module. My tests are in functions/test/send.spec.js:
// send.js
const admin = require('firebase-admin');
async function myCloudFn (email) {
const authUser = await admin.auth().getUserByEmail(email);
return authUser;
}
module.exports = { myCloudFn };
// send.spec.js
const send = require('../send.js');
jest.mock('firebase-admin', () => ({
auth: () => ({
getUserByEmail: jest.fn()
.mockResolvedValueOnce({ uid: 'foo-bar' })
.mockResolvedValueOnce(null),
}),
}));
describe('send.js', () => {
it('returns authUser from myCloudFn()', async () => {
const email = 'foo#bar.com';
const responseOptions = [{ uid: 'foo-bar' }, null];
const responsePromises = responseOptions.map(() => send.myCloudFn(email));
const responses = await Promise.all(responsePromises);
expect(responses[0]).toStrictEqual(responseOptions[0]);
expect(responses[1]).toStrictEqual(responseOptions[1]);
});
});
The test passes on the first assertion, but fails on the second. The test returns the same { uid: 'foo-bar' } object both times, but I want the test response value to be null the second time. What am I missing?
A new getUserByEmail spy is created on each auth call, it isn't called more than once.
Instead, it should be:
const mockGetUserByEmail = jest.fn();
jest.mock('firebase-admin', () => ({
auth: () => ({
getUserByEmail: mockGetUserByEmail
})
}));
...
mockGetUserByEmail
.mockResolvedValueOnce({ uid: 'foo-bar' })
.mockResolvedValueOnce(null);
const responsePromises = responseOptions.map(() => send.myCloudFn(email));
...
You can mock the resolved value once of the getUserByEmail method for each test case.
E.g.
send.js:
const admin = require('firebase-admin');
async function myCloudFn(email) {
const authUser = await admin.auth().getUserByEmail(email);
return authUser;
}
module.exports = { myCloudFn };
send.test.js:
const { myCloudFn } = require('./send');
const admin = require('firebase-admin');
jest.mock(
'firebase-admin',
() => {
const mAdmin = {
auth: jest.fn().mockReturnThis(),
getUserByEmail: jest.fn(),
};
return mAdmin;
},
{ virtual: true },
);
describe('send.js', () => {
afterAll(() => {
jest.resetAllMocks();
});
it('should returns authUser from myCloudFn()', async () => {
admin.auth().getUserByEmail.mockResolvedValueOnce({ uid: 'foo-bar' });
const actual = await myCloudFn();
expect(actual).toEqual({ uid: 'foo-bar' });
});
it('should return null', async () => {
admin.auth().getUserByEmail.mockResolvedValueOnce(null);
const actual = await myCloudFn();
expect(actual).toBeNull();
});
});
unit test result:
PASS src/stackoverflow/64575307/send.test.js (14.349s)
send.js
✓ should returns authUser from myCloudFn() (11ms)
✓ should return null (3ms)
----------|----------|----------|----------|----------|-------------------|
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files | 100 | 100 | 100 | 100 | |
send.js | 100 | 100 | 100 | 100 | |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests: 2 passed, 2 total
Snapshots: 0 total
Time: 17.321s

Stub a standalone module.exports function using rewire

I am trying to stub a module.exports function. But I have some trouble. I will give you a sudo code of the situation.
MyController.js
const sendOTPOnPhone = rewire('../../src/services/OtpService/sendOTPOnPhone')
module.exports = async function(req, res) {
const { error, data } = await sendOTPOnPhone(req.query.phone) //this is I want to stub
if(error)
return return res.send(error)
return res.send(data)
}
sendOTPService.js
module.exports = async function(phone) {
const result = await fetch(`external-api-call`)
if(result.status !== 'success')
return {
error: "Failed to send OTP!",
data: null
}
return {
error: null,
data: result
}
}
sendOTPTest.js
const expect = require('chai').expect
const request = require('supertest')
const sinon = require('sinon')
const rewire = require('rewire')
const sendOTPOnPhone = rewire('../../src/services/OtpService/sendOTPOnPhone')
const app = require('../../src/app')
describe('GET /api/v1/auth/otp/generate', function () {
it('should generate OTP', async () => {
let stub = sinon.stub().returns({
error: null,
data: "OTP sent"
})
sendOTPOnPhone.__set__('sendOTPOnPhone', stub)
const result = await request(app)
.get('/api/v1/auth/otp/generate?phone=8576863491')
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200)
expect(stub.calledOnce).to.be.true
console.log(result.body)
// expect(result).to.equal('promise resolved');
})
})
Above test is failing, stub is not being called. I don't know what am I missing? If I do this in my sendOTPService:
const sendOTP = async function() {}
module.exports = {
sendOTP
}
and this in the controller.
const { error, data } = sendOTPOnPhone.sendOTPOnPhone(req.query.phone)
It works.
But I import it like const {sendOTPOnPhone } = require('../sendOTPService') It doesn't work.
I am aware that destructing changes the reference of the object.
Can someone suggest a workaround?
Is it possible to achieve this using rewire? OR It can be done with proxyquire.Please can someone suggest?
Here is the integration testing solution using proxyquire, you should use Globally override require.
app.js:
const express = require('express');
const controller = require('./controller');
const app = express();
app.get('/api/v1/auth/otp/generate', controller);
module.exports = app;
controller.js:
let sendOTPOnPhone = require('./sendOTPOnPhone');
module.exports = async function(req, res) {
const { error, data } = await sendOTPOnPhone(req.query.phone);
if (error) return res.send(error);
return res.send(data);
};
sendOTPOnPhone.js:
module.exports = async function(phone) {
const result = await fetch(`external-api-call`);
if (result.status !== 'success')
return {
error: 'Failed to send OTP!',
data: null,
};
return {
error: null,
data: result,
};
};
sendOTP.test.js:
const request = require('supertest');
const sinon = require('sinon');
const proxyquire = require('proxyquire');
describe('GET /api/v1/auth/otp/generate', function() {
it('should generate OTP', async () => {
let stub = sinon.stub().resolves({
error: null,
data: { message: 'OTP sent' },
});
stub['#global'] = true;
const app = proxyquire('./app', {
'./sendOTPOnPhone': stub,
});
const result = await request(app)
.get('/api/v1/auth/otp/generate?phone=8576863491')
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200);
sinon.assert.calledOnce(stub);
console.log(result.body);
});
});
Integration test results with coverage report:
GET /api/v1/auth/otp/generate
{ message: 'OTP sent' }
✓ should generate OTP (2373ms)
1 passing (2s)
-------------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
-------------------|---------|----------|---------|---------|-------------------
All files | 68.75 | 25 | 50 | 73.33 |
app.js | 100 | 100 | 100 | 100 |
controller.js | 83.33 | 50 | 100 | 100 | 5
sendOTPOnPhone.js | 20 | 0 | 0 | 20 | 2-4,8
-------------------|---------|----------|---------|---------|-------------------
source code: https://github.com/mrdulin/expressjs-research/tree/master/src/stackoverflow/60599945
I have answered a similar question here stub SMS otp method (without using external dependecy like proxyquire)
basically, the problem is with exports. Move your sendOtp method to a generalized place e.g User Model or schema. Import model, stub its function. It should work fine.
you are stubbing imported property called sendOtp instead of original function.

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