A Beginner’s Guide to JUnit


If you are a beginner in Java project development, you might be interested in learning about JUnit. Programmers of all skill levels use this framework to test software applications. However, before starting with JUnit, it is essential to understand the basics of software development, testing, and Java programming.

Unit test case

A Unit test case is a unit of test in a Java program. The test is performed to check whether the code works and is free of errors. The progress bar of a JUnit test shows green when execution is progressing and red when the verification checkpoint is failed. The test can be run in development mode and production mode.

@Test annotation

The @Test annotation in a Java program allows you to declare a method with any name. It is an essential tool for testing, and can be used to time out tests, skip test cases, and more. You can use multiple methods on a single test class if needed.

@After annotation

In JUnit, @After and @Before annotations mark the lifecycle phases of a test case. For example, these annotations indicate whether a method should be called before or after another. Using these annotations helps test cases pass or fail more often.

@RepeatedTest annotation

The @RepeatedTest annotation in JUnit can be used to repeat a test repeatedly. It can be used with other annotations, such as @Tag, which allows you to filter the test results using particular tags. You can also use @DisplayName to add a customized name to the test method or @Order to set the order in which the test is executed.

@After method

The @After method should be used in an automation test script to wipe away any temporary data. This method will run only once after all the tests have finished. It can be used to set default values and clean the test environment.

Test class

A test class can be defined as a type of object that tests the software. Its methods include assertEquals, verify, and compare. These methods will return a failure message if the expected value does not match the actual one.

Test method

Test methods in Java are a vital part of the test automation process. These methods check whether the application is running correctly. In this JUnit tutorial, we’ll go over a few ways to use a test method.

Test method name

In the following example, we will use the Test method name to access the data contained in a test case. We will first create a test method called a static helper method. This static method will catch exceptions and look up a stack trace to identify the calling method. Then, we will apply a regular expression to extract values from the method name.

Test method execution

To test a method, add an @Test annotation to it. There are many different ways to use this annotation. For example, you can use it to test an entire application or to specify a default value. You can also use it to run multiple test methods in an automation test script.

Test method results

This JUnit tutorial will teach us how to use the Test method and display its results. When you run a test, it will print its effects on the console. You can see the number of failures and how many tests have failed. The next step is to know why the test case failed.