5 Best JUnit and Test Driven Development Books for Java Developers

My favorite books to learn are Test-Driven Development (TDD), JUnit, Mockito, and Unit testing in Java in depth.

Hello Java Programmers, If you want to learn JUnit and Test Driven Development in Java or want to improve your TDD skills and looking for the best resources like books and online courses then you have come to the right place.

Earlier, I have shared the best JUnit courses for Java developers, and in this article, I am going to share the best books you can read to learn Test Driven Development in Java and essential testing tools like JUnit and Mockito.

If you have done some professional Java development, you know that Unit testing is an essential thing to learn to adapt. This is the single most practice a professional developer should learn in my opinion. This is also one skill that differentiates an excellent programmer from a professional programmer.

It’s one way you can see how disciplined a programmer is?

It’s also the best way to write clean code; a code that can stand the test of time, a flexible code to accommodate future changes, and a code that you don’t afraid of while changing.

Despite several efforts to promote unit testing by the programming community and emphasize unit testing by many notable programmers, it’s still one of the lacking practices.

To encourage developers to do unit testing, I try to make it natural rather than a special thing. I have found that it’s not that programmer doesn’t want to test, or they don’t have time, it’s because they don’t really know how to unit test a non-trivial code.

It’s easy for someone to write a unit test for palindrome or prime factor program, but when it comes to writing unit test for a feature you are developing which involves database connection, threads, has a dependency on other module and don’t have a clear entry point, programmer’s lost their zeal and enthusiasm.

Since users or managers don’t care about unit tests, the programmer really doesn’t push themselves to the level they usually do to make a functional code working. How do we solve this problem? How do you develop that code sense to write a unit test? How do you decompose a big feature into small units which can be independently testable?

Does it sound like I am talking about Test-driven development (TDD)? Well, Yes. Even if you don’t follow TDD in its true sense, it will help you learn many tricks and techniques to unit test your code.

On the flip side, It’s one area where the senior developer must shine; it’s their job to promote best practices, code reviews, and unit testing among the next generation of Java developers.

This article will share the 5 Best books to learn unit testing, TDD, and JUnit, which you would love to read, which will help you learn unit testing and master the art of writing good tests. Unit testing and JUnit are synonymous in the Java world, so most of this book will teach you unit testing using JUnit.

This is good because a sound knowledge of how JUnit works and how you can use different JUnit annotations will encourage you to write more tests. If you also need online courses to go along with this book, I highly recommend you check JUnit and Mockito Crash Course on Udemy.

JUnit and Mockito Crash Course: Learn JUnit and Mockito Unit Tests

I found that we learn better when we combine an online course with a book. The course provides a quick start and helps in setup, while the book provides in-depth knowledge.

Top 5 JUnit and Test Driven Development Books for Beginner and Experienced Java Programmers

Here is my list of good books to master unit testing, JUnit, and Test Driven Development (TDD) for Java professionals. Though concept like unit testing is language agnostic, it makes sense to learn tricks in the language you best understand.

Since tools and techniques are different for each language, the core concept remains the same, and some techniques are general enough to be utilized in other object-oriented languages like C++ or C#.

1. Pragmatic Unit testing in Java with JUnit

This is the first book I read on unit testing and JUnit, and I still love to read it when I have some free time. It’s a short book, but whatever is written is absolute gold. All, Jeff Langr, Andy Hunt, and Dave Thomas have done brilliant work to first introduce the concept and process of unit testing before introducing JUnit.

The explanation flows through, and you feel you are learning something by following a small number of examples given in this book. Yes, the book is kind of light on examples, but the good thing is that every example was explained very well.

I still remember the CORRECT acronym I learned from this book, which helps you think about boundary conditions tests. CORRECT stands for

1. Conformance — does the value conform to the expected format?
2. Ordering — does value is in the expected order?
3. Range — does value is in the expected range?
4. Reference — does code reference anything external which is not in direct control of the code itself?
5. Existence — does the value exists? (null, non-null, present or absent in Collection)
6. Cardinality — Are there exactly enough values?
7. Time (absolute and relative) — Is everything happening in order? At the right time? In time?

This acronym will help you to write a complete test for boundary conditions. Another acronym I like from this book is called A-TRIP, which demonstrates the properties of a good unit test. A-TRIP stands for:

1. Automatic
2. Thorough
3. Repeatable
4. Independent
5. Professional

By reading this book, you will learn how to unit test your Java application, how to write a good test, what to test, boundary conditions, dealing with design issues to make your code more testable, and testing Gotchas like randomly failing/passing tests, test working on one machine but not on others, tests taking too long to run, etc.

Here is the link to get this book — Pragmatic Unit testing in Java with JUnit

In short, a must-read unit testing book for Java developers who like to unit tests their programs. If you like online courses, you can also combine this with the Java Unit Tests for Beginners course from Udemy to get the best of both worlds.

Practical Java Unit Testing with JUnit 5

2. Test-Driven: TDD and Acceptance TDD for Java Developers

I consider myself lucky that I come to know about this book sooner than later. If you ask me to recommend just one book on testing Java application, JUnit, and Test-driven development, this would be the one.

This is THE best book for Java developer, who wants to learn JUnit and learn how to test Java programs and test a particular class, method, or module. Lasse Koskela has done an excellent job explaining TDD and simple techniques to write unit tests.

As I said before that many Java programmer doesn’t write Unit test, not because they don’t want or they don’t know JUnit but because they lack the skill to come up with test and code that test for a particular unit of their code.

Once they know how to treat a piece of code as a Unit and write an independent test, focus on the unit, and test simple things, they, in fact, enjoy writing unit tests.

Before reading this book, I didn’t know why Singleton is an anti-pattern and how helpful an interface can be to write testable, flexible, and robust code.

Without any doubt, this is the must-read book for any Java developer, and I should have included this in my list of must-read Java Books. Coming back to content, you will learn how to write tests for core Java applications, which is the easy part, and write tests about Servlet, JSP, Spring MVC Controllers, JDBC classes, tests for Apache Velocity templates, and many more.

Here is the link to get this book — Test-Driven for Java Developers

If you prefer online courses, you can also combine this book with Practical Test-Driven Development for Java Programmers to get the best of both worlds.

Practical Test Driven Development for Java Programmers

Similar to my favorite book, Effective Java, this book also has simple explanations that are good, and examples that are non-trivial, which will keep even experienced Java programmers interested.

3. JUnit in Action, Second Edition

Like many similar titled books, like Hibernate in Action or Spring in action, this is comprehensive coverage of both JUnit as the library and testing Java application in general.

Apart from introducing JUnit, this book goes beyond that offer useful testing advice on how to use stubs and mocks to test Java applications, writing HtmlUnit and Selenium test for Java web application, testing server-side Java code using Cactus, integrating your JUnit test with build tools like ANT, and Maven, automatically running them using Jenkins and other CI tools, etc.

This book is equally useful for both beginners and senior Java developers; you can learn many tools, techniques, and processes to test your Java application. I know JUnit even before reading this book, but I have learned a lot and now use it as a reference book.

Petar Tahchiev, Felipe Leme, Vincent Massol, and Gary Gregory have done a great job in compiling all useful details about unit testing principles and tools in this book.

In one word, use this as a reference book to check how to use particular testing tools like Selenium, HtmlUnit, or Cactus and, in general, how to test different types of Java applications

but if you want a companion course then you can also checkout Learn Java Unit Testing with Junit & Mockito in 30 Steps course by Ranga Karnam. It’s a great hands-on course to learn JUnit and Mockito online.

Learn Mockito and JUnit Tutorial (Unit Testing)

4. Effective JUnit testing: A Guide for Java Developers

This is another gem from Lasse Koskela. By now, You guys should already know his masterpiece Test Driven, which I have said is a must-read book for a Java developer who wants to learn unit testing, JUnit, and TDD, but more importantly, want to improve himself to create flexible and robust software.

Effective Unit Testing is written to teach you how to write good tests, concise and to the point, expressive, useful, and maintainable.

Inspired by Roy Osherove’s all-time classic The Art of Unit Testing, Effective Unit Testing book focuses on tools and practices specific to the Java world.

It introduces you to emerging techniques like behavior-driven development (BDD) and specification by non-trivial examples and demonstrates how to add advanced and robust practices into your toolkit.

Here is the link to get this book — Effective JUnit testing: A Guide for Java Developers

Unlike previous books, like JUnit in Action, this is a general book on unit testing and teaches you to write better tests, creating testable designs, effective use of test mocks, stubs, and doubles, improving the speed of your test suites and improving readability and maintainability of your tests.

After reading Test-Driven, I actually bought this book because I was very impressed with both the author and the book. I wouldn’t say this is a must-read book, as I have not completed it yet, but I am still a good addition to your bookshelf.

And, if you need an online course to go along with this JUnit book, I recommend JUnit 5, Mockito, PowerMock, TDD, BDD & ATTD course by Andreli on Udemy.

JUnit 5, Mockito, PowerMock, TDD, BDD & ATTD

5. Practical Java Unit testing using JUnit and Mockito

Tomek Kaczanowski has done a wonderful job explaining two of the most useful open-source testing frameworks JUnit and Mockito. This book is not just about writing a unit test but about creating good tests. You will learn how to write readable and maintainable tests along with writing high-quality production code.

This book explains the key concept of unit testing, like mocks, stubs, parametrized tests, and matches with some easy-to-understand but non-trivial examples.

Tomek has also included one chapter on developing good code using Test Driven Development (TDD) to help you understand core concepts in no time.

This book also has a lot of advanced content for experienced and senior Java developers, like how to improve your existing unit tests, how to measure code quality of your tests using code coverage tools, how to avoid common mistakes while writing unit tests in Java, and using mock, stubs and test doubles cleverly.

Here is the link to get this book — Practical Java Unit testing using JUnit and Mockito

It lives up to the expectation and totally justified using the “Practical” word in its title by explaining tools, practices, and techniques, which are very important for any professional Java developer.

You can also combine this book with the Instant Test-Driven Development with Java, JUnit, and Mockito course from Udemy for better learning.

Instant Test Driven Development with Java, JUnit and Mockito

That’s all on my list of Top five books on Unit testing in Java using JUnit, Mockito, TDD, and other testing libraries. As I said, if you want to become a better developer and that too with miles ahead of the crowd, improve your unit testing skill. 5 out of 10 Java developer doesn’t know about the unit test, and out of those 5, only 2 can write high quality, readable and maintainable code.

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P. S. — If you connect better with training courses than books, here is a list of some good courses to learn from Udemy and Pluralsight: 5 Courses to learn JUnit and Test Driven Development in Java, check them out.

Learn Mockito and JUnit Tutorial (Unit Testing)