Gain insights into unit testing with JUnit 5. Learn about assertions, assumptions, nested and parameterized tests, advanced JUnit 5 concepts, and integrating tests with Maven and Gradle.

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junit5.tar.gz

mvn clean test

Unit Testing is a basic and essential skill to learn for any developer. In this course, you will learn what unit tests are, why they are important, and how to test your Java applications using the JUnit 5 Framework —  the most popular unit testing framework in the market for Java developers.

You will start with the fundamentals of Unit Testing and JUnit 5 and then gradually you will dive deep into the core concepts like assertions, assumptions, different types of tests like nested tests, parameterized tests, repeated tests, and more.

You will also learn some advanced concepts of JUnit 5 like the JUnit 5 extension model, dependency injection, how to migrate existing unit tests from JUnit 4 to JUnit 5, and how to integrate your unit tests with Maven and Gradle.

Unit Testing Java Applications using JUnit 5

**AssertJ** is a Java library used alongside JUnit 5 to write fluent assertions.

AssertJ contains feature-rich assertions and helpful error messages. This improves test code readability, and helps us debug failed unit tests.


# Different modules of AssertJ

**AssertJ** is composed of several modules:

- **Core Module** - This module provides assertions for JDK types (String, Iterable, Stream, Path, File, Map, etc.)
- **Guava:** Provides assertions for types coming from the “Guava” library (Multimap, Optional, etc.).

- **Joda Time:** This module provides assertions for Joda Time Types (DateTime, LocalDateTime).

- **Neo4J:** Provides assertions for Neo4J types (Path, Node, Relationship).

- **DB:** Provides assertions for relational database types (Table, Row, Column).

- **Swing:** Provides an API for functional testing of Swing user interfaces.


# Set up AssertJ using Maven

We use the following Maven coordinates to install the AssertJ library with Maven.



Learn about the AssetJ library, and how it helps us to write better unit tests.


Before We Begin

Introduction to JUnit 5

Junit 5 Core Concepts

Dynamic Tests

Dependency Injection in JUnit 5

JUnit 5 Extensions

Migrating from Junit 4 to Junit 5

Appendix

BONUS: Useful Assertion Libraries

Conclusion

AssertJ

Different modules of AssertJ