JavaScript Unit Testing - The Practical Guide from Udemy

Automated testing is a key concept in modern (web) development.

It is a concept that can be intimidating at first, hence many developers shy away from diving into testing and adding tests to their projects.

This course teaches you automated unit & integration testing with JavaScript from the ground up. You will learn how tests are written and added to your projects, what should (and should not) be tested and how you can test both simple as well as more complex code.

You will learn about the software and setup required to write automated tests and example projects will be provided as part of the course. It's a hands-on, practical course, hence you won't get stuck in theory - instead you'll be able to learn all key concepts at real examples.

In the course, Vitest will be used as the main testing library & tool. It's a modern JavaScript test runner and assertion library that provides Jest compatibility. Hence what you'll learn in this course will help you no matter if you're working with Vitest or Jest. And the core concepts will apply, no matter which testing setup you're using at all.

As part of this course, typical testing problems will be defined and solved and common strategies like mocking or working with spies are taught in great detail. This course also does not focus on specific types of JavaScript projects - neither does it focus on any specific library or framework.

Instead, you'll learn how to automatically test your (vanilla) JavaScript code, no matter if it's a NodeJS or frontend project. The fundamentals you'll gain in this course will help you in all your future projects - backend (NodeJS) and frontend (vanilla JS, React, Vue, Angular) alike.

This course will provide you with an extremely solid foundation to build up on, such that you can start adding tests to all your JavaScript projects.

In detail, this course will teach you:

What exactly "testing" or "automated testing" is (and why you need it)
What "unit testing" is specifically
Which tools you need to enable automated unit tests in your projects
How to write unit tests
How to get started with integration tests
How to formulate different expectations (assertions)
Which patterns to follow when writing tests
How to test asynchronous and synchronous code
How to deal with side effects with help of spies & mocks
How to apply all these concepts in real projects & examples

What's inside

Learning objectives

Write and structure unit & integration tests
Remove side effects from tests via mocking and spies

Work with popular javascript test runners and libraries
Write good tests and focus on testing core business logic

Write and structure unit & integration tests
Remove side effects from tests via mocking and spies
Work with popular javascript test runners and libraries
Write good tests and focus on testing core business logic

Syllabus

Learn what unit & integration testing is exactly and what this course has to offer for you!

Welcome To This Course!

What Is Testing?

Unit Testing: What & Why?

Unit vs Integration vs E2E Tests

A Quick Note About Test-Driven Development (TDD)

About This Course

Join Our Learning Community

Course Resources & Project Snapshots

Learn about the setup required to integrate automated tests into your projects. You'll learn about testing libraries, test runners & assertion libraries and which roles these "things" play.

Module Introduction

Which Tools Are Needed For Testing?

Jest & Vitest

Installing Vitest

Course Project Setup

Learn about the key testing fundamentals. Learn how tests are added to a project, how two write tests and which logic should go into your unit testing code.

Basic Test File & Project Setup

Writing a First Test

Running Tests

Why Are We Testing?

The AAA Pattern - Arrange, Act, Assert

Keep Your Tests Simple!

Defining Behaviors & Fixing Errors In Your Code

Demo: Writing More Tests

Testing For Errors

Demo: Adding More Tests

Testing For Thrown Errors & Error Messages

Exercise: Problem

Exercise: Solution

Tests With Multiple Assertions (Multiple Expectations)

More Practice!

Introducing Test Suites

Adding Tests To Frontend & Backend Projects

Module Summary

Learn what it takes to write good tests and how to test the right things.

What To Test & Not To Test

Writing Good Tests - An Overview & Summary

Only Test "One Thing"

Splitting Functions For Easier Testing & Better Code

Refactoring Code

Formulating Different Expectations

A Word About Code Coverage

Learn what exactly integration tests are, how they differ from unit tests and how to write + run them.

Introducing Integration Tests

Writing an Integration Test & Reasoning

Integration vs Unit Tests: Finding the Right Balance

Time to dive deeper into testing and explore some advanced testing concepts and features!

toBe() vs toEqual()

The Problem With Asynchronous Code

Testing Asynchronous Code With Callbacks

Testing Asynchronous Code With Promises & async / await

Returning Promises In Tests

Getting Started with "Testing Hooks"

Why Hooks?

Using Testing Hooks (beforeEach, beforeAll, afterEach, afterAll)

Concurrent Tests

Concurrency & Default Behavior

Learn what side effects are, which problems they can cause and how you can work around them with mocks and spies (and of course what "mocks and spies" actually are).

The Starting Project

The Problem With Side Effects & Tests

Introducing Spies & Mocks

Working with Spies

Getting Started with Mocks & Automocking

Note on Mocking

Notes on Spies

Custom Mocking Logic

Managing Custom Mock Implementations Globally (__mocks__ Folder)

More Mocking Functionalities

Let's dive a bit deeper into mocking and core mocking functionalities and concepts.

Refresher: Practicing Basic Tests (1)

Refresher: Practicing Basic Tests (2)

Reasons to Mock

Mocking Global Values & Functions

Mocking Frontend Libraries

Test-specific Mocking Logic

Mocking In Selected Places

Using Local Mock Values

Learn how to write tests that need to interact with the browser DOM.

Understanding the Problem

Working with Different Testing Environments

Setting up a Virtual HTML Page

Testing DOM Functionalities

DOM Tests & Cleanup Work

Finishing Example

A Brief Look at the "Testing Library" Package

You did it! You completed the course - great job!

Good to know

Know what's good

, what to watch for

, and possible dealbreakers

Taught by Maximilian Schwarzmüller, founder of Academind, who is a respected creator of programming courses

Develops skills in JavaScript testing, which is highly relevant in web development and programming

Suitable for beginners, as it builds a solid foundation in JavaScript testing from the ground up

Provides hands-on, practical learning through example projects and interactive materials

Covers advanced testing concepts such as mocking and spying, which are essential for effective testing

May require students to have some prior understanding of JavaScript, as it assumes some familiarity with the language

Activities

Be better prepared before your course. Deepen your understanding during and after it. Supplement your coursework and achieve mastery of the topics covered in JavaScript Unit Testing - The Practical Guide with these activities:

Create a JavaScript resource collection

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Organize and consolidate useful JavaScript resources, including tutorials, articles, and code snippets, for easy access and future reference.

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Gather resources related to JavaScript concepts and technologies
Categorize and organize the resources
Create a central repository or document to store the collection

Connect with experienced JavaScript developers

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Seek guidance and support from experienced professionals in the field, gaining valuable insights and learning from their expertise.

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Join online communities or forums related to JavaScript
Attend meetups or workshops where you can meet JavaScript developers
Reach out to potential mentors and ask for their guidance

Review basic JavaScript concepts

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Reinforce the foundational understanding of JavaScript programming principles and syntax, preparing you for the more advanced concepts explored in the course.

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Review variable declaration and data types
Practice writing simple JavaScript functions
Experiment with manipulating DOM elements using JavaScript

Six other activities

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Engage in peer-to-peer learning sessions

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Collaborate with fellow students, share knowledge, and clarify concepts through peer-to-peer learning sessions.

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Form a study group with classmates
Meet regularly to discuss course material, solve problems, and quiz each other
Provide support and encouragement to each other

Solve coding challenges on LeetCode

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Enhance your problem-solving skills and deepen your understanding of JavaScript by tackling coding challenges on platforms like LeetCode.

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Choose a challenge that aligns with the concepts covered in the course
Analyze the problem and design a solution
Implement your solution in JavaScript and test it thoroughly

Follow online tutorials on advanced JavaScript topics

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Expand your knowledge by exploring advanced JavaScript concepts through guided tutorials, broadening your understanding and skills.

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Identify a specific topic you want to deepen your understanding of
Find reputable online tutorials or courses that cover the topic
Follow the tutorials, taking notes and practicing the concepts

Build a simple JavaScript project

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Apply your newfound knowledge to a practical project, solidifying your understanding and showcasing your skills in JavaScript programming.

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Identify a project idea that aligns with your interests
Design the project architecture and components
Develop the project using JavaScript
Test and debug your project thoroughly

Participate in JavaScript hackathons or competitions

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Challenge yourself by participating in JavaScript hackathons or competitions, showcasing your skills and learning from others.

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Identify JavaScript hackathons or competitions that align with your interests
Form a team or participate individually
Develop a solution to the challenge

Contribute to JavaScript open-source projects

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Gain practical experience and contribute to the JavaScript community by participating in open-source projects, enhancing your skills and knowledge.

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Identify JavaScript open-source projects that align with your interests
Review the project documentation and codebase
Contribute fixes, enhancements, or new features to the project

Career center

Learners who complete JavaScript Unit Testing - The Practical Guide will develop knowledge and skills that may be useful to these careers:

DevOps Engineer

DevOps Engineers are responsible for bridging the gap between development and operations teams. They work with a variety of tools and techniques to automate the build, deployment, and testing of software applications. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for DevOps Engineer

Test Automation Engineer

Test Automation Engineers are responsible for automating the testing of software applications. They work with a variety of testing tools and techniques to create automated tests that can be used to test software applications for both functional and non-functional requirements. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Test Automation Engineer

Quality Assurance Analyst

Quality Assurance Analysts are responsible for ensuring that software applications meet the needs of their users and are free of defects. They work with a variety of testing tools and techniques to test software applications for both functional and non-functional requirements. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Quality Assurance Analyst

Software Tester

Software Testers are responsible for testing software applications to identify defects and ensure that they meet the needs of their users. They work with a variety of testing tools and techniques to test software applications for both functional and non-functional requirements. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Software Tester

Product Manager

Product Managers are responsible for defining the vision and roadmap for software products. They work with a variety of stakeholders, including developers, testers, and business analysts, to ensure that software products meet the needs of their users. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Product Manager

Software Engineer

As a Software Engineer, you will write and maintain code for a variety of software applications. Many Software Engineers choose to specialize in a particular area, such as web development, mobile development, or data science. This course can help you build a strong foundation in software testing, which is an essential skill for any Software Engineer. By learning how to write and run tests, you can help ensure that your software is free of defects and meets the needs of your users.

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Software Development Manager

Software Development Managers are responsible for leading and managing software development teams. They work with a variety of stakeholders, including developers, testers, and business analysts, to ensure that software development projects are completed on time and within budget. This course can help you learn how to write tests for a variety of software applications, which is essential for ensuring that your software is free of defects and meets the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Software Development Manager

Full-Stack Developer

Full Stack Developers are responsible for both the front-end and back-end development of a website or application. They work with a variety of technologies, including HTML, CSS, JavaScript, server-side programming languages, and databases. This course can help you learn how to write tests for both your front-end and back-end code, which is essential for ensuring that your applications are free of defects and meet the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Full-Stack Developer

Front-End Developer

Front End Developers are responsible for the user interface and user experience of a website or application. They work with a variety of technologies, including HTML, CSS, JavaScript, and front-end frameworks. This course can help you learn how to write tests for your front-end code, which is essential for ensuring that your applications are free of defects and meet the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Front-End Developer

Web Developer

Web Developers are responsible for designing and developing websites and web applications. They work with a variety of technologies, including HTML, CSS, JavaScript, and server-side programming languages. This course can help you learn how to write tests for your web applications, which is essential for ensuring that your applications are free of defects and meet the needs of your users. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Web Developer

Backend Developer

Backend Developers are responsible for the logic and data processing that happens behind the scenes of a website or application. They write server-side code that interacts with databases, handles user requests, and performs other tasks that are not visible to the user. This course can help you learn how to write tests for your backend code, which is essential for ensuring that your application is reliable and efficient. By learning how to test your code, you can help prevent bugs from reaching production and affecting your users.

See salaries and explore the career path for Backend Developer

Information Security Analyst

Information Security Analysts are responsible for protecting an organization's information systems from security threats. They work with a variety of tools and techniques to identify, assess, and mitigate security risks. This course may be useful for Information Security Analysts who want to learn how to test their security code. By learning how to test your code, you can help prevent security vulnerabilities from being introduced into your systems, which can lead to data breaches or other security incidents.

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IT Auditor

IT Auditors are responsible for evaluating an organization's IT systems and controls to ensure that they are operating in a compliant and efficient manner. They work with a variety of tools and techniques to identify and assess risks to an organization's IT systems. This course may be useful for IT Auditors who want to learn how to test their auditing code. By learning how to test your code, you can help prevent errors from being introduced into your auditing code, which can lead to incorrect audit results and decisions.

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Database Administrator

Database Administrators are responsible for managing and maintaining databases. They work with a variety of tools and techniques to ensure that databases are available, reliable, and secure. This course may be useful for Database Administrators who want to learn how to test their database code. By learning how to test your code, you can help prevent errors from being introduced into your database, which can lead to data loss or corruption.

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Data Analyst

Data Analysts are responsible for collecting, cleaning, and analyzing data to identify trends and patterns. They work with a variety of tools and techniques to extract insights from data that can be used to improve business decisions. This course may be useful for Data Analysts who want to learn how to test their data analysis code. By learning how to test your code, you can help prevent errors from being introduced into your data analysis, which can lead to incorrect insights and decisions.

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