---
title: "The Art of Unit Testing, 3rd Edition"
url: "https://www.artofunittesting.com/art-of-unit-testing-3rd-edition.md"
canonical: "https://www.artofunittesting.com/art-of-unit-testing-3rd-edition"
tags: []
author: "Roy Osherove"
description: "The Art of Unit Testing, Third Edition, by Roy Osherove (Manning): mocks, stubs and dependency injection in functional, modular and object oriented style, with examples in JavaScript."
usage: "Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page)."
license: "https://creativecommons.org/licenses/by/4.0/"
---

# The Art of Unit Testing, 3rd Edition

The book · with examples in JavaScript

This expanded edition teaches mocks, stubs and dependency injection in functional, modular and object oriented style.

 [![Cover of The Art of Unit Testing, Third Edition, by Roy Osherove (Manning)](https://www.artofunittesting.com/img/c/cover-400.jpg)](https://go.osherove.com/aout3)

[The Art of Unit Testing, Third Edition (opens in a new tab)](https://go.osherove.com/aout3) updates an international bestseller to reflect modern development tools and practices.

You’ll explore test patterns and organization, working with legacy code, and even “untestable” code. The many tool-agnostic examples are presented in JavaScript, and are carefully designed so that they apply to code written in any language.

[Buy the book (opens in a new tab)](https://go.osherove.com/aout3) [Free resources](https://www.artofunittesting.com/#resources)

Print + ebook from Manning · Buy links go to Manning and include Roy’s affiliate code.


---

## About the author

**Roy Osherove**: Senior Solutions Architect at AWS working on AI for production and AI-driven development; author of The Art of Unit Testing and Elastic Leadership, with about 20 years of consulting and training on unit testing, TDD, team leadership and continuous delivery.

### Sites

- [RobotPaper](https://robotpaper.ai/): This blog: AI patterns and anti-patterns, AI and coding agents, and engineering leadership.
- [osherove.com](https://osherove.com): Roy's personal site. Author of The Art of Unit Testing and Elastic Leadership; consulting and training on unit testing, TDD, team leadership and continuous delivery, plus about 20 years of blog posts.
- [The Art of Unit Testing](https://www.artofunittesting.com): The Art of Unit Testing, 3rd Edition (Manning): readable, maintainable, trustworthy unit tests, plus TDD workshops in C#, JavaScript, Java and Kotlin.
- [5whys.com](https://www.5whys.com): Roy's writing on software team leadership: self-organizing teams, surviving chaos, learning mode and the Elastic Leadership model.
- [Pipeline Driven](https://pipelinedriven.org): Continuous delivery and DevOps practices: build patterns, pipeline-friendly testing, DevOps metrics and enterprise DevOps.
- [Elastic Leadership](https://www.elasticleadership.com): Elastic Leadership, Roy's framework for software team leaders (survival, learning and self-organizing modes).

### Social

- X: https://x.com/royosherove
- LinkedIn: https://www.linkedin.com/in/osherove/

### Contact

- Contact form: https://forms.gle/jQSx5KoXvrVA1JCK7

### License

Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page). License: https://creativecommons.org/licenses/by/4.0/