Jest tests for redux-observable - jestjs

I have the following epic, the variable SampleStores has some sample data. How do I perform unit testing on this with jest?
export const incrementalSearchEpic = action$ => {
return action$.ofType('SEARCH_STORES').mergeMap(action => {
const incrementalSearchResults =
// eslint-disable-next-line max-len
SampleStores.filter(sampleStore =>
(sampleStore.Name.toLowerCase().includes(action.SearchText.toLowerCase().trim())) ||
// eslint-disable-next-line max-len
(sampleStore.Location.toLowerCase().includes(action.SearchText.toLowerCase().trim()))
).map(sampleStore => ({
type: 'FILTERED_STORE',
searchText: action.SearchText.toLowerCase().trim(),
store: sampleStore
}));
//Create the interval to emit an item every second
return Observable.interval(1000)
.take(incrementalSearchResults.length).map(t => incrementalSearchResults[t]);
});
};

Related

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 - resetting value in module and reloading import

I'm writing a test in jest for a module which uses a constant from a different module.
I want to set a different value for it for every test case, but I don't seem to be able to do so.
The test file:
import { Request, Response } from 'express';
const activityConsumer = require('../../src/utils/activity.consumer');
const mockRequest = {
params: {
activityArn: 'activityArn'
}
} as Request;
const mockedJsonFunction = jest.fn();
const mockResponse: any = {
json: jest.fn(),
status: jest.fn().mockReturnValue({ json: mockedJsonFunction }),
} as Response;
let stopConsumerMock;
describe('consumer handler', () => {
beforeAll(() => {
stopConsumerMock = activityConsumer.stopConsumer = jest.fn().mockReturnValue(1);
});
beforeEach(() => {
jest.resetModules();
});
afterEach(() => {
stopConsumerMock.mockClear();
mockResponse.json.mockClear();
});
describe('stopConsumingHandler', () => {
it('Should return success true and not call stopConsumer when no consumer exists', () => {
activityConsumer.consumer = undefined;
const { stopConsumingHandler } = require ('../../src/handlers/consumer.handlers');
stopConsumingHandler(mockRequest, mockResponse);
expect(stopConsumerMock.mock.calls.length).toEqual(0);
expect(mockResponse.json.mock.calls.length).toEqual(1);
expect(mockResponse.json).toHaveBeenCalledWith({ success: true });
});
it('Should return success true and call stopConsumer when consumer exists', () => {
activityConsumer.consumer = true;
const { stopConsumingHandler } = require ('../../src/handlers/consumer.handlers');
stopConsumingHandler(mockRequest, mockResponse);
expect(stopConsumerMock.mock.calls.length).toEqual(1);
expect(mockResponse.json.mock.calls.length).toEqual(1);
expect(mockResponse.json).toHaveBeenCalledWith({ success: true });
});
});
});
I want to replace the value of activityConsumer.consumer and then reload the consumer.handlers module but the re-assignment and reload does not seem to have any effect.
Please advise on how can I write this test properly.
Try this way, using jest.mock to modify import value of activityConsumer
import { Request, Response } from 'express';
// const activityConsumer = require('../../src/utils/activity.consumer');
const mockRequest = {
params: {
activityArn: 'activityArn'
}
} as Request;
const mockedJsonFunction = jest.fn();
const mockResponse: any = {
json: jest.fn(),
status: jest.fn().mockReturnValue({ json: mockedJsonFunction }),
} as Response;
let stopConsumerMock;
describe('consumer handler', () => {
beforeAll(() => {
// stopConsumerMock = activityConsumer.stopConsumer = jest.fn().mockReturnValue(1);
stopConsumerMock = jest.fn().mockReturnValue(1);
});
beforeEach(() => {
jest.resetModules(); // important line
});
afterEach(() => {
stopConsumerMock.mockClear();
mockResponse.json.mockClear();
});
describe('stopConsumingHandler', () => {
it('Should return success true and not call stopConsumer when no consumer exists', () => {
// activityConsumer.consumer = undefined;
// mock by this way
jest.mock('../../src/utils/activity.consumer', () => ({
consumer: undefined,
stopConsumer: stopConsumerMock,
}));
const { stopConsumingHandler } = require('../../src/handlers/consumer.handlers');
stopConsumingHandler(mockRequest, mockResponse);
expect(stopConsumerMock.mock.calls.length).toEqual(0);
expect(mockResponse.json.mock.calls.length).toEqual(1);
expect(mockResponse.json).toHaveBeenCalledWith({ success: true });
});
it('Should return success true and call stopConsumer when consumer exists', () => {
// activityConsumer.consumer = true;
// mock by this way
jest.mock('../../src/utils/activity.consumer', () => ({
consumer: true, // mock value for consumer
stopConsumer: stopConsumerMock,
}));
const { stopConsumingHandler } = require('../../src/handlers/consumer.handlers');
stopConsumingHandler(mockRequest, mockResponse);
expect(stopConsumerMock.mock.calls.length).toEqual(1);
expect(mockResponse.json.mock.calls.length).toEqual(1);
expect(mockResponse.json).toHaveBeenCalledWith({ success: true });
});
});
});

How to test objection.js with jest?

Model.knex(knex);
const app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(i18nextMiddleware);
I want to test method getUsers of users controller. It get data from usersModel getUsers method. I get date from MySQL by Objections ORM.
app.get(
'/',
checkFilter(['type']),
users.getUsers
);
According to instructions, I am changing the query method.
class MyQueryBuilder extends QueryBuilder {
query() {
return this.resolve({ test: 11111 });
}
}
class UsersModel extends Model {
static get QueryBuilder() {
return MyQueryBuilder;
}
}
jest.spyOn(Users, 'query')
.mockImplementation(UsersModel.query);
Describe test.
describe('get errors', () => {
beforeAll(done => {
i18next.on('initialized', () => {
done()
});
});
it('with filter', done => {
request(app)
.get('/')
.query({page: 0, perPage: 5, type: 'admin'})
.end((err, res) => {
if (err) return done(err);
expect(res.status).toBe(200);
expect(
Object.keys(res.body).sort()
).toEqual([
'items',
'itemsOnPage',
'currentPage',
'totalPage',
'totalItems'
].sort());
expect(res.body.items).toHaveLength(8);
expect(res.body.totalItems).toBe(usersMockDB.getUsers.length);
console.log(res.body);
done();
});
});
afterAll(done => {
knex.destroy();
done();
})
});
Method getUsers of users model.
const { Users } = require('../../db/models/Users');
const query = Users
.query()
.select(
'id',
'login',
'type',
'edit',
'email',
'phone',
'block'
)
.orderBy('id', 'DESC')
.page(page, perPage);
// filter
if (Object.keys(usersFilter).length) {
for (let field in usersFilter) {
if ( usersFilter.hasOwnProperty(field) ) {
query.where(field, 'like', `%${ usersFilter[field] }%`);
}
}
}
const { results, total } = await query;
return {
items: results,
itemsOnPage: Number(perPage),
currentPage: Number(page),
totalPage: Math.ceil(total/perPage),
totalItems: Number(total)
}
Should I override methods page and where ? As I understand it, they make new database queries.
This may not be desirable in every case, but I find that the easiest solution for unit tests that use objection models is to create one transaction per test. This does mean you'll need a database to run tests, but everything is rolled back between tests.
In jest.config.js, add this line
setupFilesAfterEnv: ['./jest.setup.js'],
in jest.setup.js:
import objection from 'objection';
import knex from './src/db/index.js'; // Change src/db/index.js to the path to the file where you export your knex instance
const {transaction, Model} = objection;
global.beforeAll(async () => {
global.knex = knex;
global.txn = null;
});
global.beforeEach(async () => {
global.txn = await transaction.start(knex);
Model.knex(global.txn);
});
global.afterEach(async () => {
await global.txn.rollback();
Model.knex(knex);
});
global.afterAll(async () => {
global.knex.destroy();
});
You can then use your models as expected in your code and unit tests
import {User} from './src/db/models/index.js';
it('creates and reads users', async () => {
const user = await User.query().insert({email: 'test#test.com'});
const users = await User.query();
expect(users).toHaveLength(1);
});
it('does not persist users between tests', async () => {
const users = await User.query();
expect(users).toHaveLength(1);
});

Jest reset mock of a node module

I'm working on the Google Cloud Functions tests.
The files are these:
index.ts which only exports the functions which are also imported there.
if (!process.env.FUNCTION_NAME || process.env.FUNCTION_NAME === 'contactSupportByMail') {
exports.contactSupportByMail = require('./contactSupportByMail');
}
contactSupportByMail.ts the function to test.
And the test:
describe('Cloud Functions', (): void => {
let myFunctions;
let adminInitStub;
beforeAll((): void => {
// [START stubAdminInit]
// If index.js calls admin.initializeApp at the top of the file,
// we need to stub it out before requiring index.js. This is because the
// functions will be executed as a part of the require process.
// Here we stub admin.initializeApp to be a dummy function that doesn't do anything.
adminInitStub = sinon.stub(admin, 'initializeApp');
testEnv.mockConfig({
sendgrid: {
key: 'apiKey',
},
brand: {
support_email: 'supportEmail',
},
});
// [END stubAdminInit]
});
afterAll((): void => {
// Restore admin.initializeApp() to its original method.
adminInitStub.restore();
// Do other cleanup tasks.
process.env.FUNCTION_NAME = '';
myFunctions = undefined;
testEnv.cleanup();
});
describe('contactSupportByMail', (): void => {
// Mocking node_modules library before the require
jest.mock('#sendgrid/mail', (): { [key: string]: any } => ({
setApiKey: (): void => { },
send: (): Promise<any> => Promise.resolve('ok'),
}));
// Setting up cloud function name
process.env.FUNCTION_NAME = 'contactSupportByMail';
// Importing the index file
myFunctions = require('../src/index');
const wrapped = testEnv.wrap(myFunctions.contactSupportByMail);
it('it should export contactSupportByMail', (): void => {
const cFunction = require('../src/contactSupportByMail');
assert.isObject(myFunctions);
assert.include(myFunctions, { contactSupportByMail: cFunction });
});
it('should fully work', async (): Promise<void> => {
const onCallObjects: [any, ContextOptions] = [
{ mailBody: 'mailBody', to: 'toEmail' },
{ auth: { token: { email: 'userEmail' } } },
];
return assert.deepEqual(await wrapped(...onCallObjects), { ok: true });
});
it('not auth', async (): Promise<void> => {
await expect(wrapped(undefined)).rejects.toThrow('The function must be called while authenticated.');
});
it('sendgrid error', async (): Promise<void> => {
// Mocking node_modules library before the require
jest.mock('#sendgrid/mail', (): { [key: string]: any } => ({
setApiKey: (): void => { },
send: (): Promise<any> => Promise.reject('errorsengrid'),
}));
// Importing the index file
const a = require('../src/index');
const wrapped_2 = testEnv.wrap(a.contactSupportByMail);
const onCallObjects: [any, ContextOptions] = [
{ mailBody: 'mailBody', to: 'toEmail' },
{ auth: { token: { email: 'userEmail' } } },
];
await expect(wrapped_2(...onCallObjects)).rejects.toThrow('errorsengrid');
});
});
});
The problem is provoking the sendgrid error. I don't know how to reset the mock of sendgrid's library which is required inside contactSupportByMail. After mocking it for the first time, it always returns the send function as resolved.
Just a note - if using babel-jest, mock calls are hoisted to the top of the transpiled js... doMock allow you to mock in the before functions of a test.
This is one way to mock a module for some tests within a file - and restore it for the others:
describe("some tests", () => {
let subject;
describe("with mocks", () => {
beforeAll(() => {
jest.isolateModules(() => {
jest.doMock("some-lib", () => ({ someFn: jest.fn() }));
subject = require('./module-that-imports-some-lib');
});
});
// ... tests when some-lib is mocked
});
describe("without mocks - restoring mocked modules", () => {
beforeAll(() => {
jest.isolateModules(() => {
jest.unmock("some-lib");
subject = require('./module-that-imports-some-lib');
});
});
// ... tests when some-lib is NOT mocked
});
});
I finally got the solution:
afterEach((): void => {
jest.resetModules();
});

Jest: how to restore to a previous mocked implementation (not the original)

I have a set of 3 tests, the first one has the base mocked implementation:
Team.query = jest.fn(() => ({
findOne: () => {
return {
is_disabled: false,
};
},
}));
In the second test, I perform a Team.query.mockImplementationOnce with the above, but I change is_disabled to true.
In the third test, I want to restore it back to the jest.fn implementation above. Is this possible?
You're good, no extra work required.
Since Team.query is the mock function, it will automatically revert to the previously mocked implementation after one call when it has been overridden with mockImplementationOnce:
const Team = { };
Team.query = jest.fn(() => ({
findOne: () => {
return {
is_disabled: false,
};
},
}));
test('Team.query', () => {
expect(Team.query().findOne().is_disabled).toBe(false); // Success!
Team.query.mockImplementationOnce(() => ({ findOne: () => ({ is_disabled: true }) }));
expect(Team.query().findOne().is_disabled).toBe(true); // Success!
expect(Team.query().findOne().is_disabled).toBe(false); // Success!
Team.query.mockImplementationOnce(() => ({ findOne: () => ({ is_disabled: 'some text' }) }));
expect(Team.query().findOne().is_disabled).toBe('some text'); // Success!
expect(Team.query().findOne().is_disabled).toBe(false); // Success!
});

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