Jest.fn().mockReturnValue returns undefined - jestjs

Below mentioned mocked function when used in a file called useFirestore gives the following error: Cannot read property 'collection' of undefined.
firebase.js
import Firebase from 'firebase/app';
import 'firebase/storage';
import 'firebase/firestore';
import 'firebase/auth';
const config = {'// Firebase config'};
const firebase = !Firebase.apps.length ? Firebase.initializeApp(config) : Firebase.app;
export const { serverTimestamp } = Firebase.firestore.FieldValue;
export default firebase;
setupTests.js
import '#testing-library/jest-dom';
jest.mock('./firebase', () => ({
storage: jest.fn(),
firestore: jest.fn().mockReturnedValue({
collection: jest.fn().mockReturnThis(),
orderBy: jest.fn().mockReturnThis(),
onSnapshot: jest.fn().mockReturnThis(),
}),
}));
Custom Hook
import firebase from '../firebase';
function useFirestore(collectionName) {
const [docs, setDocs] = React.useState(null);
const [loading, setLoading] = React.useState(true);
React.useEffect(() => {
const unsub = firebase
.firestore() // logs cannot read property collection of undefined
.collection(collectionName)
.orderBy('createdAt', 'desc')
.onSnapshot(
(snapshot) => {
setDocs(snapshot.docs.map((doc) => ({ id: doc.id, ...doc.data() })));
setLoading(false);
},
(err) => {
console.log(err);
}
);
return unsub;
}, [collectionName]);
return {
docs,
loading,
};
}
export default useFirestore;
jest.config.js
module.exports = {
collectCoverageFrom: [
'src/**/*.{js,jsx}',
'!<rootDir>/node_modules/',
'!<rootDir>/coverage/',
'!<rootDir>/build/',
],
moduleNameMapper: { '\\.(css|scss)$': '<rootDir>/src/utils/__mocks__/stylemock.js' },
setupFilesAfterEnv: ['<rootDir>/src/setupTests.js'],
};
As mentioned the above configuration returns undefined. However, when I change the mock implemenation of firestore to the following, it works correctly.
jest.mock('./firebase', () => ({
storage: jest.fn(),
firestore: () => ({ // not using jest.fn() and mockReturnValue
collection: jest.fn().mockReturnThis(),
orderBy: jest.fn().mockReturnThis(),
onSnapshot: jest.fn().mockReturnThis(),
}),
}));
Please guide if anything's wrong here. Thanks

Simply a typo my friend! No such thing as mockReturnedValue on type jest.Mock, you probably want to use mockReturnValue.

Related

TypeError: firebase_admin_1.default.messaging is not a function

I am trying to write unit tests using jest and trying to mock firebase-admin.
Here is my application code:
import logger from './logger';
import admin from 'firebase-admin';
class NotificationService {
constructor() {
admin.initializeApp({
credential: admin.credential.cert({
projectId: 'FCM_PROJECT_ID',
privateKey: 'FCM_PRIVATE_KEY'
clientEmail: 'FCM_CLIENT_EMAIL'
}),
});
}
public async send(message: TokenMessage): Promise<ApiResponse<string>> {
try {
await admin.messaging().send(message)
} catch (e) {
logger.error(e);
}
}
}
I am trying to mock the code like below:
jest.mock('firebase-admin');
But it is erroring out with:
firebase_admin_1.default.messaging is not a function
What is the solution?
Issue: not mocking the member variables and methods(messaging, send) of firebase-admin.
Fix:
jest.mock('firebase-admin', () => ({
messaging: jest.fn().mockImplementation(() => {
return {
send: jest
.fn()
.mockReturnValue('message_id'),
};
}),
}));
Note: You would probably need to mock credential and initializeApp as well:
jest.mock('firebase-admin', () => ({
credential: {
cert: jest.fn(),
},
initializeApp: jest.fn(),
messaging: jest.fn().mockImplementation(() => {
return {
send: jest
.fn()
.mockReturnValue('message_id'),
};
}),
}));

Jest mock Knex transaction

I have the following lambda handler to unit test. It uses a library #org/aws-connection which has a function mysql.getIamConnection which simply returns a knex connection.
Edit: I have added the mysql.getIamConnection function to the bottom of the post
Edit: If possible, I'd like to do the testing with only Jest. That is unless it becomes to complicated
index.js
const {mysql} = require('#org/aws-connection');
exports.handler = async (event) => {
const connection = await mysql.getIamConnection()
let response = {
statusCode: 200,
body: {
message: 'Successful'
}
}
try {
for(const currentMessage of event.Records){
let records = JSON.parse(currentMessage.body);
await connection.transaction(async (trx) => {
await trx
.table('my_table')
.insert(records)
.then(() =>
console.log(`Records inserted into table ${table}`))
.catch((err) => {
console.log(err)
throw err
})
})
}
} catch (e) {
console.error('There was an error while processing', { errorMessage: e})
response = {
statusCode: 400,
body: e
}
} finally {
connection.destroy()
}
return response
}
I have written some unit tests and I'm able to mock the connection.transaction function but I'm having trouble with the trx.select.insert.then.catch functions. H
Here is my testing file
index.test.js
import { handler } from '../src';
const mocks = require('./mocks');
jest.mock('#org/aws-connection', () => ({
mysql: {
getIamConnection: jest.fn(() => ({
transaction: jest.fn(() => ({
table: jest.fn().mockReturnThis(),
insert: jest.fn().mockReturnThis()
})),
table: jest.fn().mockReturnThis(),
insert: jest.fn().mockReturnThis(),
destroy: jest.fn().mockReturnThis()
}))
}
}))
describe('handler', () => {
test('test handler', async () =>{
const response = await handler(mocks.eventSqs)
expect(response.statusCode).toEqual(200)
});
});
This test works partially but it does not cover the trx portion at all. These lines are uncovered
await trx
.table('my_table')
.insert(records)
.then(() =>
console.log(`Records inserted into table ${table}`))
.catch((err) => {
console.log(err)
throw err
})
How can set up my mock #org/aws-connection so that it covers the trx functions as well?
Edit:
mysql.getIamConnection
async function getIamConnection (secretId, dbname) {
const secret = await getSecret(secretId)
const token = await getToken(secret)
let knex
console.log(`Initialzing a connection to ${secret.proxyendpoint}:${secret.port}/${dbname} as ${secret.username}`)
knex = require('knex')(
{
client: 'mysql2',
connection: {
host: secret.proxyendpoint,
user: secret.username,
database: dbname,
port: secret.port,
ssl: 'Amazon RDS',
authPlugins: {
mysql_clear_password: () => () => Buffer.from(token + '\0')
},
connectionLimit: 1
}
}
)
return knex
}
Solution
#qaismakani's answer worked for me. I wrote it slightly differently but the callback was the key. For anyone interested here is my end solution
const mockTrx = {
table: jest.fn().mockReturnThis(),
insert: jest.fn().mockResolvedValue()
}
jest.mock('#org/aws-connection', () => ({
mysql: {
getIamConnection: jest.fn(() => ({
transaction: jest.fn((callback) => callback(mockTrx)),
destroy: jest.fn().mockReturnThis()
}))
}
}))
Updating your mock to look like this might do the trick:
const { mysql } = require("#org/aws-connection");
jest.mock("#org/aws-connection", () => ({
mySql: {
getIamConnection: jest.fn()
}
}));
const mockTrx = {
table: jest.fn().mockReturnThis(),
insert: jest.fn().mockResolveValue() // Resolve any data here
};
mysql.getIamConnection.mockReturnValue({
transaction: jest.fn((callback) => callback(mockTrx)),
});
You need to mock the transaction so that it executes your callback with a dummy trx. To do this, you need to make sure that all the functions inside the trx object return a reference back to it or a promise so that you can chain it appropriately.
Instead of mocking knex implementation, I've written knex-mock-client which allows you to mimic real db with an easy API.
Change your mock implementation with
import { handler } from "../src";
import { getTracker } from "knex-mock-client";
const mocks = require("./mocks");
jest.mock("#org/aws-connection", () => {
const knex = require("knex");
const { MockClient } = require("knex-mock-client");
return {
mysql: {
getIamConnection: () => knex({ client: MockClient }),
},
};
});
describe("handler", () => {
test("test handler", async () => {
const tracker = getTracker();
tracker.on.insert("my_table").responseOnce([23]); // setup's a mock response when inserting into my_table
const response = await handler(mocks.eventSqs);
expect(response.statusCode).toEqual(200);
});
});

Jest - testing sequelize with Nest.js

I'm testing a nest.js service, this method basically will receive a find method from sequelize:
...
import { Auth } from './../../modules/auth/entities/auth.entity';
import { Sequelize } from 'sequelize-typescript';
import { getModelToken } from '#nestjs/sequelize';
jest.mock('./../../modules/auth/auth.service');
const sequelize = new Sequelize({ validateOnly: true });
sequelize.addModels([Auth]);
const testAuth = new Auth({
id_user: '1',
});
describe('AuthGuardService', () => {
let service: AuthGuardService;
let authService: AuthService;
beforeEach(async () => {
const module: TestingModule = await Test.createTestingModule({
providers: [
AuthGuardService,
AuthService,
{
provide: getModelToken(Auth),
useValue: { findOne: jest.fn(() => testAuth) },
},
],
imports: [HttpModule],
}).compile();
service = module.get<AuthGuardService>(AuthGuardService);
authService = module.get<AuthService>(AuthService);
});
...
it('it should return true', async () => {
expect(
await authService.find({
id: '1',
})
).toEqual(testAuth);
});
on my service I'm trying to test this exactly block:
const user = await this.authService.find({
id: value,
});
if(user.id === some_value) {
return true;
}
but I always get undefined when I tried to read user from my test.
TypeError: Cannot read property 'id' of undefined

How to mock AxiosInstance with jest [duplicate]

I'm using jest and axios-mock-adapter to test axios API calls in redux async action creators.
I can't make them work when I'm using a axios instance that was created with axios.create() as such:
import axios from 'axios';
const { REACT_APP_BASE_URL } = process.env;
export const ajax = axios.create({
baseURL: REACT_APP_BASE_URL,
});
which I would consume it in my async action creator like:
import { ajax } from '../../api/Ajax'
export function reportGet(data) {
return async (dispatch, getState) => {
dispatch({ type: REQUEST_TRANSACTION_DATA })
try {
const result = await ajax.post(
END_POINT_MERCHANT_TRANSACTIONS_GET,
data,
)
dispatch({ type: RECEIVE_TRANSACTION_DATA, data: result.data })
return result.data
} catch (e) {
throw new Error(e);
}
}
}
Here is my test file:
import {
reportGet,
REQUEST_TRANSACTION_DATA,
RECEIVE_TRANSACTION_DATA,
} from '../redux/TransactionRedux'
import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'
import { END_POINT_MERCHANT_TRANSACTIONS_GET } from 'src/utils/apiHandler'
import axios from 'axios'
import MockAdapter from 'axios-mock-adapter'
const middlewares = [thunk]
const mockStore = configureMockStore(middlewares)
const store = mockStore({ transactions: {} })
test('get report data', async () => {
let mock = new MockAdapter(axios)
const mockData = {
totalSalesAmount: 0
}
mock.onPost(END_POINT_MERCHANT_TRANSACTIONS_GET).reply(200, mockData)
const expectedActions = [
{ type: REQUEST_TRANSACTION_DATA },
{ type: RECEIVE_TRANSACTION_DATA, data: mockData },
]
await store.dispatch(reportGet())
expect(store.getActions()).toEqual(expectedActions)
})
And I only get one action Received: [{"type": "REQUEST_TRANSACTION_DATA"}] because there was an error with the ajax.post.
I have tried many ways to mock the axios.create to no avail without really knowing what I'm doing..Any Help is appreciated.
OK I got it. Here is how I fixed it! I ended up doing without any mocking libraries for axios!
Create a mock for axios in src/__mocks__:
// src/__mocks__/axios.ts
const mockAxios = jest.genMockFromModule('axios')
// this is the key to fix the axios.create() undefined error!
mockAxios.create = jest.fn(() => mockAxios)
export default mockAxios
Then in your test file, the gist would look like:
import mockAxios from 'axios'
import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'
// for some reason i need this to fix reducer keys undefined errors..
jest.mock('../../store/rootStore.ts')
// you need the 'async'!
test('Retrieve transaction data based on a date range', async () => {
const middlewares = [thunk]
const mockStore = configureMockStore(middlewares)
const store = mockStore()
const mockData = {
'data': 123
}
/**
* SETUP
* This is where you override the 'post' method of your mocked axios and return
* mocked data in an appropriate data structure-- {data: YOUR_DATA} -- which
* mirrors the actual API call, in this case, the 'reportGet'
*/
mockAxios.post.mockImplementationOnce(() =>
Promise.resolve({ data: mockData }),
)
const expectedActions = [
{ type: REQUEST_TRANSACTION_DATA },
{ type: RECEIVE_TRANSACTION_DATA, data: mockData },
]
// work
await store.dispatch(reportGet())
// assertions / expects
expect(store.getActions()).toEqual(expectedActions)
expect(mockAxios.post).toHaveBeenCalledTimes(1)
})
If you need to create Jest test which mocks the axios with create in a specific test (and don't need the mock axios for all test cases, as mentioned in other answers) you could also use:
const axios = require("axios");
jest.mock("axios");
beforeAll(() => {
axios.create.mockReturnThis();
});
test('should fetch users', () => {
const users = [{name: 'Bob'}];
const resp = {data: users};
axios.get.mockResolvedValue(resp);
// or you could use the following depending on your use case:
// axios.get.mockImplementation(() => Promise.resolve(resp))
return Users.all().then(data => expect(data).toEqual(users));
});
Here is the link to the same example of Axios mocking in Jest without create. The difference is to add axios.create.mockReturnThis()
here is my mock for axios
export default {
defaults:{
headers:{
common:{
"Content-Type":"",
"Authorization":""
}
}
},
get: jest.fn(() => Promise.resolve({ data: {} })),
post: jest.fn(() => Promise.resolve({ data: {} })),
put: jest.fn(() => Promise.resolve({ data: {} })),
delete: jest.fn(() => Promise.resolve({ data: {} })),
create: jest.fn(function () {
return {
interceptors:{
request : {
use: jest.fn(() => Promise.resolve({ data: {} })),
}
},
defaults:{
headers:{
common:{
"Content-Type":"",
"Authorization":""
}
}
},
get: jest.fn(() => Promise.resolve({ data: {} })),
post: jest.fn(() => Promise.resolve({ data: {} })),
put: jest.fn(() => Promise.resolve({ data: {} })),
delete: jest.fn(() => Promise.resolve({ data: {} })),
}
}),
};
In your mockAdapter, you're mocking the wrong instance. You should have mocked ajax instead. like this, const mock = MockAdapter(ajax)
This is because you are now not mocking the axios instance but rather the ajax because it's the one you're using to send the request, ie, you created an axios instance called ajax when you did export const ajax = axios.create...so since you're doing const result = await ajax.post in your code, its that ajax instance of axios that should be mocked, not axios in that case.
I have another solution.
import {
reportGet,
REQUEST_TRANSACTION_DATA,
RECEIVE_TRANSACTION_DATA,
} from '../redux/TransactionRedux'
import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'
import { END_POINT_MERCHANT_TRANSACTIONS_GET } from 'src/utils/apiHandler'
// import axios from 'axios'
import { ajax } from '../../api/Ajax' // axios instance
import MockAdapter from 'axios-mock-adapter'
const middlewares = [thunk]
const mockStore = configureMockStore(middlewares)
const store = mockStore({ transactions: {} })
test('get report data', async () => {
// let mock = new MockAdapter(axios)
let mock = new MockAdapter(ajax) // this here need to mock axios instance
const mockData = {
totalSalesAmount: 0
}
mock.onPost(END_POINT_MERCHANT_TRANSACTIONS_GET).reply(200, mockData)
const expectedActions = [
{ type: REQUEST_TRANSACTION_DATA },
{ type: RECEIVE_TRANSACTION_DATA, data: mockData },
]
await store.dispatch(reportGet())
expect(store.getActions()).toEqual(expectedActions)
})
another method: add this file to src/__mocks__ folder
import { AxiosStatic } from 'axios';
const axiosMock = jest.createMockFromModule<AxiosStatic>('axios');
axiosMock.create = jest.fn(() => axiosMock);
export default axiosMock;
The following code works!
jest.mock("axios", () => {
return {
create: jest.fn(() => axios),
post: jest.fn(() => Promise.resolve()),
};
});

How to mock chained function calls using jest?

I am testing the following service:
#Injectable()
export class TripService {
private readonly logger = new Logger('TripService');
constructor(
#InjectRepository(TripEntity)
private tripRepository: Repository<TripEntity>
) {}
public async showTrip(clientId: string, tripId: string): Promise<Partial<TripEntity>> {
const trip = await this.tripRepository
.createQueryBuilder('trips')
.innerJoinAndSelect('trips.driver', 'driver', 'driver.clientId = :clientId', { clientId })
.where({ id: tripId })
.select([
'trips.id',
'trips.distance',
'trips.sourceAddress',
'trips.destinationAddress',
'trips.startTime',
'trips.endTime',
'trips.createdAt'
])
.getOne();
if (!trip) {
throw new HttpException('Trip not found', HttpStatus.NOT_FOUND);
}
return trip;
}
}
My repository mock:
export const repositoryMockFactory: () => MockType<Repository<any>> = jest.fn(() => ({
findOne: jest.fn(entity => entity),
findAndCount: jest.fn(entity => entity),
create: jest.fn(entity => entity),
save: jest.fn(entity => entity),
update: jest.fn(entity => entity),
delete: jest.fn(entity => entity),
createQueryBuilder: jest.fn(() => ({
delete: jest.fn().mockReturnThis(),
innerJoinAndSelect: jest.fn().mockReturnThis(),
innerJoin: jest.fn().mockReturnThis(),
from: jest.fn().mockReturnThis(),
where: jest.fn().mockReturnThis(),
execute: jest.fn().mockReturnThis(),
getOne: jest.fn().mockReturnThis(),
})),
}));
My tripService.spec.ts:
import { Test, TestingModule } from '#nestjs/testing';
import { TripService } from './trip.service';
import { MockType } from '../mock/mock.type';
import { Repository } from 'typeorm';
import { TripEntity } from './trip.entity';
import { getRepositoryToken } from '#nestjs/typeorm';
import { repositoryMockFactory } from '../mock/repositoryMock.factory';
import { DriverEntity } from '../driver/driver.entity';
import { plainToClass } from 'class-transformer';
describe('TripService', () => {
let service: TripService;
let tripRepositoryMock: MockType<Repository<TripEntity>>;
let driverRepositoryMock: MockType<Repository<DriverEntity>>;
beforeEach(async () => {
const module: TestingModule = await Test.createTestingModule({
providers: [
TripService,
{ provide: getRepositoryToken(DriverEntity), useFactory: repositoryMockFactory },
{ provide: getRepositoryToken(TripEntity), useFactory: repositoryMockFactory },
],
}).compile();
service = module.get<TripService>(TripService);
driverRepositoryMock = module.get(getRepositoryToken(DriverEntity));
tripRepositoryMock = module.get(getRepositoryToken(TripEntity));
});
it('should be defined', () => {
expect(service).toBeDefined();
expect(driverRepositoryMock).toBeDefined();
expect(tripRepositoryMock).toBeDefined();
});
describe('TripService.showTrip()', () => {
const trip: TripEntity = plainToClass(TripEntity, {
id: 'one',
distance: 123,
sourceAddress: 'one',
destinationAddress: 'one',
startTime: 'one',
endTime: 'one',
createdAt: 'one',
});
it('should show the trip is it exists', async () => {
tripRepositoryMock.createQueryBuilder.mockReturnValue(trip);
await expect(service.showTrip('one', 'one')).resolves.toEqual(trip);
});
});
});
I want to mock the call to the tripRepository.createQueryBuilder().innerJoinAndSelect().where().select().getOne();
First question, should I mock the chained calls here because I assume that it should already be tested in Typeorm.
Second, if I want to mock the parameters passed to each chained call and finally also mock the return value, how can I go about it?
I had a similar need and solved using the following approach.
This is the code I was trying to test. Pay attention to the createQueryBuilder and all the nested methods I called.
const reactions = await this.reactionEntity
.createQueryBuilder(TABLE_REACTIONS)
.select('reaction')
.addSelect('COUNT(1) as count')
.groupBy('content_id, source, reaction')
.where(`content_id = :contentId AND source = :source`, {
contentId,
source,
})
.getRawMany<GetContentReactionsResult>();
return reactions;
Now, take a look at the test I wrote that simulates the chained calls of the above methods.
it('should return the reactions that match the supplied parameters', async () => {
const PARAMS = { contentId: '1', source: 'anything' };
const FILTERED_REACTIONS = REACTIONS.filter(
r => r.contentId === PARAMS.contentId && r.source === PARAMS.source,
);
// Pay attention to this part. Here I created a createQueryBuilder
// const with all methods I call in the code above. Notice that I return
// the same `createQueryBuilder` in all the properties/methods it has
// except in the last one that is the one that return the data
// I want to check.
const createQueryBuilder: any = {
select: () => createQueryBuilder,
addSelect: () => createQueryBuilder,
groupBy: () => createQueryBuilder,
where: () => createQueryBuilder,
getRawMany: () => FILTERED_REACTIONS,
};
jest
.spyOn(reactionEntity, 'createQueryBuilder')
.mockImplementation(() => createQueryBuilder);
await expect(query.getContentReactions(PARAMS)).resolves.toEqual(
FILTERED_REACTIONS,
);
});
Guilherme's answer is totally right. I just wanted to offer a modified approach that might apply to more test cases, and in TypeScript. Instead of defining your chained calls as (), you can use a jest.fn, allowing you to make more assertions. e.g.,
/* eslint-disable #typescript-eslint/no-explicit-any */
const createQueryBuilder: any = {
select: jest.fn().mockImplementation(() => {
return createQueryBuilder
}),
addSelect: jest.fn().mockImplementation(() => {
return createQueryBuilder
}),
groupBy: jest.fn().mockImplementation(() => {
return createQueryBuilder
}),
where: jest.fn().mockImplementation(() => {
return createQueryBuilder
}),
getRawMany: jest
.fn()
.mockImplementationOnce(() => {
return FILTERED_REACTIONS
})
.mockImplementationOnce(() => {
return SOMETHING_ELSE
}),
}
/* run your code */
// then you can include an assertion like this:
expect(createQueryBuilder.groupBy).toHaveBeenCalledWith(`some group`)
The solution I found to work in my case was to
create a repository class, add your custom query to the class
#EntityRepository(User)
export class UserRepository extends Repository<User> {
async getStatus(id: string) {
const status = await this.createQueryBuilder()
.select('User.id')
.where('User.id = :id', { id })
.getRawOne();
return {status};
}
}
mock the new repository class using 'jest-mock-extended' and 'jest-when' dependencies. This way you only need to mock the UserRepository and not all it's nested queries.
Now you can define the behaviour of the repository to resolve a predefined object (in my case a Partial object).
// some file where I need to call getStatus() in a test
const userRepoMock = mock<UserRepository>()
// lines omitted
const user = {
status: open,
};
when(userRepoMock.getStatus).mockResolvedValue(user as User);
// assert status

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