Gain insights into configuring and utilizing JUnit 5 for Java unit testing. Learn about writing effective unit tests, integrating assertions, assumptions, parameterized tests, and their significance.

Junit 5 is the most popular and widely used Java unit testing framework. In this course, you will learn step by step, how to configure and use JUnit 5 testing framework. This course will teach you how to write unit tests with JUnit 5, covering topics like why unit tests are important, the structure of good unit tests, assertions, assumptions and parameterized tests and more.

Java Unit Testing with JUnit 5

# ParameterResolver ###

In previous JUnit versions, there was **limited/no** support to allow parameters in test constructors or methods. 
One of the major changes in JUnit 5 Jupiter was that both test constructors and test methods are now allowed to have parameters. These parameters provide metadata to constructors and test methods. Thus, allows for greater flexibility and enables Dependency Injection for test methods and constructors.

In Junit 5, there is an interface in `org.junit.jupiter.api.extension` package by name, `ParameterResolver`. This interface defines the API for test extensions that wish to dynamically resolve parameters at runtime. 

There are different types of ParameterResolver's in Junit 5. Generally, if a test constructor or a `@Test`, `@BeforeEach`, `@AfterEach`, `@BeforeAll`, `@AfterAll` or `@TestFactory` method accepts a parameter, the parameter must be resolved at runtime by a registered `ParameterResolver`.

Read more - 
https://junit.org/junit5/docs/5.3.2/api/org/junit/jupiter/api/extension/package-summary.html for `org.junit.jupiter.api.extension`

https://junit.org/junit5/docs/5.3.2/api/org/junit/jupiter/api/extension/ParameterResolver.html for `ParameterResolver`.


This lesson demonstrates how to use dependency injection (TestInfo Parameter) in Constructor and Test methods.

Getting Started

Assertions in Junit 5

Junit 5 Test Lifecycle Callbacks

Display Names

Dependency Injection for Constructors and Methods

Assumptions in Junit 5

Disable or Enable Tests in Junit 5

Nested Tests in Junit 5

JUnit 5 Integration with Maven

Parameterized Tests in Junit 5

Repeated Tests in Junit 5

Appendix

TestInfo parameter

ParameterResolver