What is JUnit?
JUnit is a simple, open-source Unit Testing framework tool to write and run repeatable unit tests. Also, it is an instance of the xUnit architecture for unit testing frameworks. It is mostly used as a Unit testing tool by most developers.
JUnit main features are as below:
- Annotations to mark the methods as Test methods.
- Assertions for testing expected results/actual results.
Test runner for running tests as shown in the below picture.
JUnit 4 Maven dependency
If your build tool is Maven, then add a dependency to JUnit to pom.xml. Replace the minor version to the latest stable version.
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.xx</version> <scope>test</scope> </dependency>
JUnit 4 Annotations:
Annotations mark the tests as test cases ex: with @Test. The most common JUnit 4 annotations are:
@Test
@Before
@After
A simple JUnit test:
The @Test annotation tells JUnit that the method to which it is attached can be run as a test case. Also, to run the method, JUnit first constructs a fresh instance of the class then invokes the annotated method. In addition, any exceptions thrown by the test will be reported by JUnit as a failure. If no exceptions are thrown, the test is assumed to have succeeded.
@Test
public void testMethod()
{
assertEquals(1, 1);
}
https://www.testingdocs.com/anatomy-of-a-junit-test/
In conclusion, the most recommended tool for writing/executing Java unit tests is JUnit. JUnit 4 is a major API revision release ( However, a new version JUnit5 is around the corner).
JUnit Tutorial on this website can be found at:
https://www.testingdocs.com/junit-tutorial/
More information on JUnit official website: