Unit Testing for Typescript & NodeJs Developers with Jest (Udemy.com)
Master unit testing with NodeJs, Typescript, Jest and React. Write top quality Typescript and NodeJs software with Jest
Created by: Alex Dan
Last updated August 2026
What you will learn
- Basics of TypeScript unit testing with Jest
- Integration tests with TypeScript
- Test Driven Development (TDD) with Jest
- Unit testing React with TypeScript and Jest
- CICD with GitHub Actions and Docker
- Jest - the basics: hooks, assertions, matchers
- Jest - the advanced parts: aliases, custom matchers, snapshots
- Advanced unit testing techniques using Jest
- Database operations testing with Docker and Jest
Course Description
A must have skill for senior developers
Typescript is getting more and more popularity and it is a required skill for many IT jobs. It's key feature is type safety, thus preventing bugs.
But yes another skill is very important for any programming job: unit testing. Combining these two techniques will result in solid, robust and bug free code.
This course will go beyond the basics of unit testing and teach you all you need to write real world, complex testing suites for NodeJs and Typescript applications using the most popular JavaScript testing library: Jest.
Using Jest as an unit testing library provides many advantages:
Unitary unit testing library for running and structuring tests
Extensive mocking, stubbing and spying capabilities
Powerful matchers to create simple to read tests
Jest ships as one unitary NPM package
Jest is the default choice for TypeScript React projects
Why unit testing NodeJs apps?
Unit testing usually adds a lot to a code base, two or tree times in some cases. This also means that a lot of time needs to be invested in writing and setting up tests. But all this effort pays of: time, effort and headache of fixing bugs can be used for more fun activities.
What you will get from this course:
setup NodeJs and Typescript projects from scratch
implement unit testing with Jest
learn about unit testing configuration with parameters like: roots, transform, testRegex or verbose
learn about Jest test suites structure: describe with value, test, descriptions, hooks like beforeEach
basic and advanced assertions, comparing primitive types, objects or even errors
instantiating test double objects like mocks, stubs, spies or fakes.
write complex mock objects which can be used with "strange" JavaScript libraries.
inject doubles: directly inside the constructor, over the module or even using the objects prototype
learn about deep mocks and matchers to make your tests even better
integration tests for a NodeJs server application
Conditionally and asynchronously skip tests
Dedicated sections on unit testing mocks:
Jest mocks, spies
How to use stubs
London/Chicago testing approach, with the advantages and disadvantages of each one
In this course you will learn how to use Test Driven Development (TDD):
Analyze the advantages of TDD
Hands-on practice with a great coding kata: password checker
Separate section on Jest Integration tests for Rest APIs:
learn how to setup integration tests
learn the difference between integration tests and unit tests
write integration tests for a Rest API with Jest
Dedicated section on Jest React unit testing:
How to test for React components with Jest
How to test React async code
How to debug React Typescript apps
The examples used in the course follow very high coding guidelines for Typescript, NodeJs and React. Async/await syntax is used for clear and concise code, and of course, you will see how to test asynchronous code, on server, but also in the front end.
Course advantages:
Respect for your time: most of the time of the instructor typing is cut off, the course is focused on unit tests and Jest explanations
Concise: learn only what you need, no fillers to make the course falsely more appealing
Experienced and programming active instructor: a great teacher never looses touch with the industry. This is especially true for software development, where the industry is so dynamic. This helps the instructor stay up to date with the best coding guidelines and present you the challenging parts, not the "hello world"
Organized course structure: six parts, progressive approach, consistent content
Code changes in each lecture on Git with code diffs: this will help you get an concise overview of the lecture and correct in case you missed something
Big font, dark background, fullHD content, this way it is readable even on a small screen or even tablet.
Lifetime access
Certificate of completion to present to your current or prospective employer
Do you want your Typescript or NodeJs code to have the best quality, and your project to be safe?
Enroll and start writing your tests in 10 minutes!
Instructor Details
- 4.3 Rating
2,055 Reviews
Alex Dan
Alex Dan — Cloud Architect, Developer & Instructor
With over a decade of hands-on software engineering experience, I've built my career at the intersection of cloud infrastructure, web development, and practical education.
My technical journey started in embedded automotive systems — developing Java-based navigation solutions for major car brands. From there, I moved into cloud engineering, building AWS-powered data pipelines for connected vehicles using Node.js, TypeScript, Lambda, DynamoDB, and a full suite of AWS services. I later worked as a Node.js developer at one of Eastern Europe's largest e-commerce platforms, before transitioning into independent cloud architecture consulting.
Today, as a freelance Cloud Architect, I design and implement scalable cloud solutions across industries — from automotive to enterprise — with a focus on infrastructure reliability, CI/CD automation, and modern serverless architectures.
Parallel to my engineering career, I've been teaching on Udemy since 2017, growing a community of over 300,000 students across 19 courses. My current focus is AI-assisted development — helping developers work smarter with tools like GitHub Copilot, VS Code AI extensions, and agentic coding workflows.
More courses by Alex Dan
AWS & Typescript Masterclass - CDK, Serverless, React (2026)
4.6 (2,034 Reviews)
Provider: Udemy
Time: 13.2h
$84.99
Amazon Bedrock - The Complete Guide to AWS Generative AI (2026)
4.7 (1,564 Reviews)
Provider: Udemy
Time: 9.4h
$79.99
Generative AI for NodeJs: OpenAI, LangChain - TypeScript (2026)
4.5 (844 Reviews)
Provider: Udemy
Time: 7.4h
$89.99
More Node.js courses
Learn and Understand NodeJS (V8, Express, MERN/PERN & more) (2025)
4.7 (31,374 Reviews)
Provider: Udemy
Time: 14.6h
$119.99
Node.js, Express, MongoDB & More: The Complete Bootcamp (2024)
4.7 (30,347 Reviews)
Provider: Udemy
Time: 42.2h
$159.99
NestJS: The Complete Developer's Guide (2026)
4.7 (9,487 Reviews)
Provider: Udemy
Time: 19.8h
$89.99
Complete NodeJS Developer (GraphQL, MongoDB, + more) (2026)
4.7 (5,544 Reviews)
Provider: Udemy
Time: 46.5h
$94.99
Reviews
By Ek Mo on 8/13/2026
Overall it was a good course since it goes over a lot of concepts and the basics work well. I'd recommend updating the things that have changed in the last 2-3 years to make the student experience a little better.
By Kanhaiyalal Sharma on 9/30/2025
Thank you for presenting Jest in such a structured and systematic way. The step-by-step explanation made the concepts easier to follow, and the organized flow helped me connect theory with practical examples. The structured teaching style really clarified how to approach testing with Jest, from basics to more advanced scenarios. It gave me confidence to start writing and running my own test cases effectively.
By Simone Radice on 2/4/2025
The course is complete and it goes through different topics and environments regarding code testing. Starting from simple unit tests, integration tests and ending up to useful React examples. The only "negative" thing is that at some point, there's a lot of coding and not so much explaining, which can make it difficult to understand what is going on... anyways I would still recommend it!
By Áron László Kovács on 6/3/2024
this course based on jest, it was very informative, i am learned some new skills, and deapthen my knowledge in jest, such as mock, spies, and other features which this testing libary has. the CICD section was short, but this course primarily promised an introduction to the jest library. "big like" to be shown some practice in react testing, and show me how to be tested an asynchronous event
By Ricardo Andre Pikussa on 4/18/2024
Should explain better what are the methods of Jest and their usage, why to use them and only them implement code with them. The way the course was made may indicates that we should know everything before start the course.
By S San on 3/16/2024
started off well, but began to feel rushed and not well explained midway. It didnt make a good learning experience and quite difficult to follow along with the fast scrolling and context switching. had to pause some parts and refer to his code to understand/follow along with his reasoning as instructor talked too fast. Some parts could of been expanded upon in more depth like integration testing as it was relatively short. and maybe more section review/ or exercises to practise/consolidate the learning. Overall it was ok for an introduction to testing
By Aldo on 4/4/2023
It was a great course. Definitely learned a lot on testing with typescript and node. I also will take courses that cover testing with express and a sql/noSql databases as this wasn't mentioned in this particular course. Thanks!
By Sai Subash Mallireddy on 7/16/2022
The course content is excellent. But the content delivery could be better. A smooth transition between files and narration could've made the course; easy to follow. Also, please find time to reply to the questions in the lectures, thanks .
By David Kempf on 2/28/2022
Course is good with good tips working with Jest mocking techniques. pro: Good explanation between mockReturnValueOnce() and mockRejectedValueOnce()! contra: React-Tests are not the best way to do it: -> ReactDOM better alternatives: render, screen from '@testing-library/react' -> fireEvent better alternative: userEvent from '@testing-library/user-event' Also have a look: https://testing-library.com/docs/dom-testing-library/cheatsheet/ I would much more prefer using it in the way its made for. querySelector() to get DOM elements in Tests can be hard to read and also you have much more ways for assertions with @testing-library/react.
By Colin R on 12/6/2020
Alex is a very good instructor. He explains everything well and at a good pace. The source project provided is thorough and provides great examples of different types of testing techniques and TypeScript patterns. There's also lots of great bits of information regarding VSCode as an IDE and debugging node effectively.
Quality Score
No CourseDuck member has rated this course yet. Taken it? Give each part a thumbs up or down.
Overall Score : 86 / 100












