This repository contains the source code for the book 30 Testing Tools & Libraries Every Java Developer Must Know.

Testing is a critical part of software development, and having the right tools can make all the difference.

This book introduces you to 30 essential testing tools and libraries, carefully selected to cover a wide range of testing needs—from unit testing and assertions to mocking, integration testing, and performance testing.

Each tool is presented in a cookbook-style format, with clear explanations and hands-on examples that you can apply directly to your projects.

• Enrich your testing toolbox with 30 carefully curated tools and libraries.
• Choose the right tool for the job by understanding the strengths and use cases of each.
• Explore the Java testing ecosystem through practical, real-world examples.
• Apply testing best practices to your Spring Boot, Jakarta EE, or any Java application.
• Gain hands-on experience with each tool through dedicated examples and exercises.

The book is now complete with 30/30 tools and libraries covered.

You can grab your copy here.

This repository contains the source code for the examples used in the book. The examples are organized into two projects:

• spring-boot-example: Demonstrates testing tools and libraries in the context of a Spring Boot application. You'll find most of the code examples here.
• jakarta-ee-example: Showcases testing tools and libraries using a Jakarta EE application.

Each tool and library has its dedicated Java package within the spring-boot-example/src/test/java/de/rieckpil/blog directory of the respective project.

The only exception is MicroShed Testing, which is part of the jakarta-ee-example project.

Requirements:

• Java 21: Verify with java -version
• A running Docker engine: docker info

Build the project and run all tests with:

cd spring-boot-example
./mvnw verify

cd jakarta-ee-example
./mvnw verify

• JUnit 4
• JUnit 5
• TestNG
• Spock

• AssertJ
• JsonPath
• Hamcrest
• XMLUnit
• JSONAssert
• REST Assured

• Mockito
• WireMock
• MockWebServer

• Testcontainers
• LocalStack
• MicroShed Testing
• GreenMail
• Selenide
• Selenium

• JGiven

• Pact
• Diffblue
• Pit
• Instancio
• ArchUnit
• Awaitility

• Gatling
• ApacheBench
• JMH
• JfrUnit