Nodejs Express - unit testing/integration tests with Jest

Name: Nodejs Express - unit testing/integration tests with Jest
Rating: 4.5 (1663 reviews)

Learn to build a full CRUD REST API with Nodejs using TDD in Jest in JavaScript, with unit testing and integration test

Created byStefan Hyltoft

Last updated 11/2019

English

English [Auto],

What you'll learn

Learn how to make unit tests
Learn how to make integration tests
Learn how to create a Express REST API from scratch
Learn how to build a Express REST API with test-driven development
Learn how to mock Mongoose models in Nodejs with Jest
Learn how to use Jest with TDD to build a REST API
Learn how to use MongoDB with Mongoose together with Jest tests
Learn how to write tests for error handling

Course content

9 sections • 62 lectures • 2h 47m total length

Initialising project1:18
Learn how to initialise our NodeJs Express test-driven development project with Jest
Hello World Express REST API in less than 5 mins!3:50
Learn how to create a simple Nodejs Express REST API in just 10 minutes!
CRUD Methods we are going to build the TDD-way in REST1:30
A brieft introduction to the various REST HTTP Methods we can use inside the Nodejs Express REST API.
Short intro to Jest + How to install Jest in our project0:39
How to install Jest to use with Nodejs Express for test-driven development

Our first test with Jest and Express REST API3:55
Making our first test with Jest for Nodejs Express REST API with test-driven development
Making our first test with Jest + Express REST API pass!1:16
Making our first test with Jest for Nodejs Express REST API with test-driven development PASS
Make Jest run automatically on file changes1:21
How to setup Jest to automatically run on file changes in our Nodejs Express app

Defining a data model for our Todo items with Mongoose3:27
Defining our Mongoose/MongoDB model to use with our Express REST API.
Using jest.fn to mock our Mongoose model functions4:04
How to use jest.fn() to mock functions in our Mongoose model to verify that our Express controller has called the model correctly
Making our test with Jest mock model pass1:40
Making our jest.fn() to mock functions in our Mongoose model to verify that our Express controller has called the model correctly
How to configure Jest test environment1:28
How to setup our Jest test environment correctly when using Mongoose inside Nodejs Express.
How to mock Request and Response objects in Express API3:22
How to use node-mocks-http package to verify that our Nodejs Express Request and Response objects have been used correctly
Writing test with mock Request object and making it pass!2:45
How to write a Jest test with node-mocks-http Request object with the Express controller and making the test pass
Using beforeEach in Jest tests1:17
Testing if response code is 201 and response is sent2:36
How can we test if the response status code is set correctly and that the response is actually being sent back in Nodejs Express with Jest?
Test if response is sending back JSON body4:47
How to test if JSON body is being sent back correctly in our Nodejs Express REST API with Jest

Creating our first integration test with Supertest and Jest6:35
How to make our Express app ready for integration testing1:49
Export the express app for supertest, then implement the todos post route to return 201 for resource creation, bridging unit tests to true integration testing.
Creating our Express Router3:15
How to debug tests in Jest2:08
Setting up Express JSON request body middleware1:00
Add express.json middleware in App.js to parse JSON payloads on post endpoints, ensuring request.body is populated for tests.
Fix for address already in use error1:04
Fix the address already in use error by preventing double app.listen during tests, so the test app runs only once and avoids unhandled promise rejection.
Making our controller function use async/await3:00
Setting up our MongoDB database in the cloud!2:03
Creating a MongoDB database user1:24
Connect to MongoDB database with Mongoose3:17
Connect a node express API to a cloud MongoDB using mongoose by creating a connect module, exporting a connect function, and wiring it into app.js for integration tests.
Modify our unit tests to use async/await3:29
Creating a server.js for running our Express REST API manually2:08
Manual Testing with Postman3:05

Oops! We're missing error handling!2:55
Explore error handling in unit and integration tests using Jest, by validating required fields like title and done in a to-do model and preventing unhandled promise rejections.
Unit tests for error handling3:16
Making our error handling unit test PASS0:54
Creating a integration test for error handling1:41
Manual test for error handling1:14
Making a test for errors returning JSON body0:47
Create middleware to parse errors in JSON2:30
Making all of our tests pass and final manual test!2:02
Align the unit and integration tests with Jest by matching expected and received errors, then run a final manual Postman test to verify proper error handling.

Intro + first test exercise1:26
Making first test for getTodos pass1:36
Test if TodoModel.find is called3:22
Test if response is being sent back correctly4:33
Create a jest test for the get todos controller to return status 200 with a json body of all todos, using a mocked Todo.find.
Test for error handling3:47
Experiment with error handling in a Node.js Express app by writing async tests with Jest that verify next is called with an error and implement try-catch in the todo controller.
Integration test for GET /todos3:58
Manual test with Postman0:56

Intro + Getting first test done2:42
Learn to implement and test the get todo by id endpoint, create a focused unit test to ensure the method exists, and validate fetching a single todo by id.
Creating mock function TodoModel.findById and test for calls3:14
Exercise! Make test for response and make test pass!1:43
Write a unit test that mocks Todo.findById to return a todo item, asserts a 200 response and a json body matching the Todo in an express route, using Jest.
Solution to response testing with getById()4:19
Error handling unit test2:53
Implement error handling tests in a Node.js Express app using Jest, asserting rejected promises propagate via next and handling not-found items in the get by id controller.
If TodoModel could not be found in database2:30
Handle the not-found TodoModel case by returning a 404 when an item is missing, and update tests to mock find by ID returning null.
Integration test for GET /todos/:todoId3:57
404 Integration test + final manual tests3:07

Intro to PUT method and first test1:06
Test if TodoModel.findByIdAndUpdate is called4:49
Test if PUT response is sent back3:06
Test HTTP PUT error handling2:17
HTTP PUT 404 test2:09
Explore updating a non-existent todo by id, which returns a 404 with a null update result, validated by unit tests, and proceed to the integration test in the next lecture.
HTTP PUT Integration test3:58
HTTP put integration test for updating a todo in a rest api, validating status 200 and updated title and done fields, and add a 404 test case.

Using Jest.mock instead of multiple Jest.fn + Intro to final challenge!2:58
Learn to implement the delete endpoint in nodejs express, test the http delete by finding by ID and deleting the Todo, and use jest.mock to replace the whole Todo model.
Unit tests for HTTP Delete method8:14
Learn to test the http delete method from unit to integration tests in node express, covering find by id and delete, 200 responses, and 404 not found handling.
Integration test for HTTP Delete Method + manual test + you are awesome!!6:11
BONUS - coupons for other courses0:12

Requirements

Basic JavaScript ES6
Some familiarity with Nodejs Express is a plus

Description

Learn how to write a full CRUD REST API with Nodejs, Express and Jest using the test-driven development method!

TDD is becoming more and more of standard, and for good reasons!

With TDD, you can feel more safe and secure that any changes you make are not breaking existing functionality in your applications. Manual tests cannot be sustainable in large applications, or even medium applications. Plus, they're incredibly tedious.

Without TDD... well, you know the story. You try to add functionality while trying to touch the existing code as little as possible, because you don't want to break things unintentionally..

With TDD you won't be scared to make big refactors in your code to clean up messy code, you will know quickly if you've broken any existing functionality!

I'll show you step-by-step how to create a REST API with Express with unit tests and integration tests using the Jest test framework. There's going to be lots of opportunities for you to work on your own and do some exercises as well for optimal learning!

If you have any questions or suggestions to the course, feel free to message me anytime, I love interacting with my students!

Who this course is for:

Students somewhat familiar with Nodejs who wants to learn how to make production-ready software with TDD

Nodejs Express - unit testing/integration tests with Jest

What you'll learn

Explore related topics

Course content

Hello world Express And Jest in less than 10 minutes!4 lectures • 7min

Our first unit test with Jest3 lectures • 7min

Our first unit tests for HTTP POST /todos9 lectures • 25min

First integration test on HTTP POST /todos13 lectures • 34min

How to write error handling unit tests + integration tests8 lectures • 15min

HTTP GET on /todos route7 lectures • 20min

HTTP GET on /todos/:todoId8 lectures • 24min

HTTP PUT /todos - the TDD way6 lectures • 17min

HTTP DELETE4 lectures • 18min

Requirements

Description

Who this course is for: