Building Your First Junit 5 Test

This lesson provides step by step hands-on approach to run JUnit 5 test case on Eclipse IDE.

Project Setup

Please install the following softwares on your machine.

Java 8

JUnit 5 tests will run with Java 8 or above. Please download and install the latest update of Java 8 or above from the official Oracle web site. www.oracle.com/technetwork/java/javase/downloads/index.html .

After installing Java, you can check your Java version by running the following command -

Eclipse Oxygen or above

You can download the latest version from Eclipse web site - https://www.eclipse.org/downloads/packages/release/neon/3/eclipse-ide-java-ee-developers .

Steps to write your first Junit 5 test case in Eclipse

Step 1 - Launch Eclipse IDE.

Step 2 - Create a new Java Project. Right click on File --> New --> Java Project as demonstrated in the figure below.

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A new popup window by name “New Java Project” will be opened as shown in the figure below.

Step 3 - Provide a Project name: say, Junit5

Step 4 - Select JRE as 1.8 and above.

Step 5 - Click Finish.

A new Java Project will be created by name - Junit5

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It’s a best practice to create JUnit test cases in the test folder.

Step 6 - Expand the Junit5 Java project. Right-click on project root. Traverse to Build Path --> New Source Folder... as shown in the figure below.

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Step 7 - A "New Source Folder" popup will be opened as shown in the figure below.

Step 8 - Provide folder name as "test" and click Finish.

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Step 9 - Right-click on test folder and traverse to New --> Junit Test Case as demonstrated in the figure below.

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Step 10 - A "New Junit Test Case" popup will be opened as shown in the figure below.

In order to create a new JUnit 5 test case, perform the following steps:-

Step 11 - Select "New Junit Jupiter test". This will create Junit 5 test case.

Step 12 - Provide any package name of your choice.

Step 13 - Provide class name as, FirstJunit5Test.

Step 14 - Click Finish.

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Step 15 - Add JUnit 5 library to the build path. Click Ok as shown in the figure below.

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A new test class by name “FirstJunit5Test” will be created. It will have following snippet of code as shown below.

package io.educative.junit5;
import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;
class FirstJunit5Test {
	@Test
	void test() {
		fail("Not yet implemented");
	}
}

It has a method “test()”. This method has an annotation as, @Test. It signifies that this is a test method in to which we write our code to test.

Step 16 - Right-click on editor window and run as Junit test case, as shown in the figure below.

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The test case fails as shown in fig below. It gives “AssertionFailedError: Not yet implemented”. It is because in test() method it is written ‘fail(“Not yet implemented”)’ assertion. This assertion fails the test case as it is not yet implemented. More on @Test and fail() in upcoming lessons.

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Building Your First JUnit 5 Test

In the next lesson, we will look into @Test annotation in JUnit 5.