JUnit 5 @AfterEach Annotation Example

JUnit 5 @AfterEach annotation is replacement of @After annotation in JUnit 4. It is used to signal that the annotated method should be executed after each @Test method in the current class.

@AfterEach Annotation Usage

Annotate a method with @AfterEach as given below:

@AfterEach
public void cleanUpEach(){
	System.out.println("After Each cleanUpEach() method called");
}

@AfterEach annotated method MUST NOT be a static method otherwise it will throw runtime error.

org.junit.platform.commons.JUnitException: @AfterEach method 'public static void com.howtodoinjava.junit5.examples.JUnit5AnnotationsExample.cleanUpEach()' must not be static.
	at org.junit.jupiter.engine.descriptor.LifecycleMethodUtils.assertNonStatic(LifecycleMethodUtils.java:73)
	at org.junit.jupiter.engine.descriptor.LifecycleMethodUtils.lambda$findAfterEachMethods$3(LifecycleMethodUtils.java:60)
	at java.util.ArrayList.forEach(ArrayList.java:1249)
	at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080)
	at org.junit.jupiter.engine.descriptor.LifecycleMethodUtils.findAfterEachMethods(LifecycleMethodUtils.java:60)

@AfterEach Annotation Example

Let’s take an example. I have used one Calculator class and added one add method. I will test it 5 times using @RepeatedTest annotation. This annotation will cause the add test to run 5 times. For every run of test method, @AfterEach annotated method should also run every time.

package com.howtodoinjava.junit5.examples;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.RepeatedTest;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInfo;
import org.junit.platform.runner.JUnitPlatform;
import org.junit.runner.RunWith;

@RunWith(JUnitPlatform.class)
public class JUnit5AnnotationsExample {

	@Test
	@DisplayName("Add operation test")
	@RepeatedTest(5)
	void addNumber(TestInfo testInfo) {
		Calculator calculator = new Calculator();
		Assertions.assertEquals(2, calculator.add(1, 1), "1 + 1 should equal 2");
	}
	
	@AfterAll
	public static void cleanUp(){
		System.out.println("After All cleanUp() method called");
	}
	
	@AfterEach
	public void cleanUpEach(){
		System.out.println("After Each cleanUpEach() method called");
	}

}

Where Calculator class is:

package com.howtodoinjava.junit5.examples;

public class Calculator 
{
	public int add(int a, int b) {
		return a + b;
	}
}

Now execute the test and you will see below console output:

After Each cleanUpEach() method called
After Each cleanUpEach() method called
After Each cleanUpEach() method called
After Each cleanUpEach() method called
After Each cleanUpEach() method called
After Each cleanUpEach() method called
After All cleanUp() method called

Clearly, @AfterEach annotated cleanUpEach() method is called once per test method invocation.

Happy Learning !!