01_pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>ac.simons</groupId>
	<artifactId>junit5demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>junit5demo</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.3.RELEASE</version>
		<relativePath/>
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>10</java.version>

		<!-- Use most recent failsafe and surefire plugin versions -->
		<maven-failsafe-plugin.version>2.22.0</maven-failsafe-plugin.version>
		<maven-surefire-plugin.version>2.22.0</maven-surefire-plugin.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<!-- Exclude JUnit 4 from starter-test (and all other related test-starter, i.e
			     those for security and project reactor -->
			<exclusions>
				<exclusion>
					<groupId>junit</groupId>
					<artifactId>junit</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
		<!-- Provide JUnit 5 API -->
		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-api</artifactId>
			<scope>test</scope>
		</dependency>
		<!-- and the engine for surefire and failsafe -->
		<dependency>
			<groupId>org.junit.jupiter</groupId>
			<artifactId>junit-jupiter-engine</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
			<!-- Spring Boot configures surefire by default, but not failsafe -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-failsafe-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>

02_ExampleServiceTest.java

// A unit test
package ac.simons.junit5demo;

import static org.junit.jupiter.api.Assertions.*;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

class ExampleServiceTest {
	@Test
	@DisplayName("Example Service should work!")
	void exampleServiceShouldWork() {
		var exampleService = new ExampleService();

		assertEquals("Hello, JUnit 5\n", exampleService.getGreeting());
	}
}

03_Junit5demoApplicationIT.java

// An integration test
package ac.simons.junit5demo;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;

@ExtendWith(SpringExtension.class)
@SpringBootTest
class Junit5demoApplicationIT {
	@Test
	void contextLoads() {
	}
}