Hands-On Introduction to the Java Testing Ecosystem

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

You can find the source code for the various testing tools & libraries within spring-boot-example/src/test/java/de/rieckpil/blog. Each tool & library has its dedicated Java package.

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

Current Status: 21/30 tools and libraries are covered. The final release (30/30) is scheduled for Q1 2025.

Grab your copy here.

Goals of the Book

• Enrich your existing testing toolbox
• Use the right tool for the job
• Inform about various tools & libraries of the Java testing ecosystem
• Cookbook-style introduction for each testing tool & library
• Hands-on testing examples that apply for testing any Java application

Build & Test

Requirements:

• Java 21: java -version
• A running Docker engine (required for Testcontainers): docker info

Build the project and run all tests with:

cd spring-boot-example
./mvnw verify

cd jakarta-ee-example
./mvnw verify

Content

The book uses a Spring Boot and Jakarta EE application to demonstrate the different tools & libraries. Both sample applications only use a minimal subset of Spring Boot/Jakarta EE features so that you can easily apply the knowledge to your tech stack.

Test Frameworks

• JUnit 4
• JUnit 5
• TestNG
• Spock

Assertion Libraries

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

Mocking Frameworks

• Mockito
• WireMock
• MockWebServer

Test Infrastructure

• Testcontainers
• LocalStack
• MicroShed Testing
• GreenMail
• Selenide
• Selenium (upcoming)

Utility Libraries

• Pact (upcoming)
• Diffblue (upcoming)
• Pit (upcoming)
• Instancio (upcoming)
• ArchUnit (upcoming)
• Awaitility (upcoming)

Performance Testing

• Gatling
• ApacheBench
• JMH (upcoming)
• JfrUnit (upcoming)