JUnit

JUnit is a widely-used open-source testing framework for Java applications, primarily designed for unit testing. It provides annotations, assertions, and test runners to help developers write and execute repeatable tests, ensuring code reliability and quality. It is a core component of test-driven development (TDD) in the Java ecosystem.

Also known as: JUnit5, JUnit 4, JUnit Framework, Java Unit Testing, JUnit Jupiter

Why learn JUnit?

Developers should learn JUnit to implement automated unit tests for Java code, which helps catch bugs early, refactor safely, and maintain code quality in projects of all sizes. It is essential for Java-based applications, especially in enterprise environments, microservices, and when following agile methodologies like TDD or continuous integration.

Learning Resources

• docs: JUnit 5 User Guide
• video: JUnit Tutorial for Beginners - Java Brains
• course: JUnit and Mockito Crash Course - Udemy
• book: JUnit in Action, 3rd Edition
• tutorial: JUnit 5 Tutorial - Baeldung