Unit Testing for Typescript & NodeJs Developers with Jest

25.09.2023 - New section for CICD with GitHub actions and Docker

1.03.2023 - Complete remaster of the course with the latest Jest and TypeScript features

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!