Validate our own tests work with JUnit5 and the vintage engine

Closes gh-14737

Co-authored-by: Stephane Nicoll <snicoll@pivotal.io>

spring-boot-samples/spring-boot-sample-data-jpa/src/test/java/sample/data/jpa/SampleDataJpaApplicationTests.java

@@ -20,14 +20,12 @@ import java.lang.management.ManagementFactory;
 
 import javax.management.ObjectName;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.test.context.ActiveProfiles;
-import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.web.context.WebApplicationContext;
@@ -43,33 +41,32 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * @author Oliver Gierke
  * @author Dave Syer
  */
-@RunWith(SpringRunner.class)
 // Enable JMX so we can test the MBeans (you can't do this in a properties file)
 @SpringBootTest(
 		properties = { "spring.jmx.enabled:true", "spring.datasource.jmx-enabled:true" })
 @ActiveProfiles("scratch")
 // Separate profile for web tests to avoid clashing databases
-public class SampleDataJpaApplicationTests {
+class SampleDataJpaApplicationTests {
 
 	@Autowired
 	private WebApplicationContext context;
 
 	private MockMvc mvc;
 
-	@Before
+	@BeforeEach
 	public void setUp() {
 		this.mvc = MockMvcBuilders.webAppContextSetup(this.context).build();
 	}
 
 	@Test
-	public void testHome() throws Exception {
+	void testHome() throws Exception {
 
 		this.mvc.perform(get("/")).andExpect(status().isOk())
 				.andExpect(content().string("Bath"));
 	}
 
 	@Test
-	public void testJmx() throws Exception {
+	void testJmx() throws Exception {
 		assertThat(ManagementFactory.getPlatformMBeanServer()
 				.queryMBeans(new ObjectName("jpa.sample:type=HikariDataSource,*"), null))
 						.hasSize(1);

spring-boot-samples/spring-boot-sample-data-jpa/src/test/java/sample/data/jpa/service/CityRepositoryIntegrationTests.java

@@ -15,15 +15,13 @@
  */
 package sample.data.jpa.service;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 import sample.data.jpa.domain.City;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
-import org.springframework.test.context.junit4.SpringRunner;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -32,15 +30,14 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Oliver Gierke
  */
-@RunWith(SpringRunner.class)
 @SpringBootTest
-public class CityRepositoryIntegrationTests {
+class CityRepositoryIntegrationTests {
 
 	@Autowired
 	CityRepository repository;
 
 	@Test
-	public void findsFirstPageOfCities() {
+	void findsFirstPageOfCities() {
 		Page<City> cities = this.repository.findAll(PageRequest.of(0, 10));
 		assertThat(cities.getTotalElements()).isGreaterThan(20L);
 	}

spring-boot-samples/spring-boot-sample-data-jpa/src/test/java/sample/data/jpa/service/HotelRepositoryIntegrationTests.java

@@ -17,8 +17,7 @@ package sample.data.jpa.service;
 
 import java.util.List;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 import sample.data.jpa.domain.City;
 import sample.data.jpa.domain.Hotel;
 import sample.data.jpa.domain.HotelSummary;
@@ -30,7 +29,6 @@ import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort.Direction;
-import org.springframework.test.context.junit4.SpringRunner;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -39,9 +37,8 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Oliver Gierke
  */
-@RunWith(SpringRunner.class)
 @SpringBootTest
-public class HotelRepositoryIntegrationTests {
+class HotelRepositoryIntegrationTests {
 
 	@Autowired
 	CityRepository cityRepository;
@@ -50,7 +47,7 @@ public class HotelRepositoryIntegrationTests {
 	HotelRepository repository;
 
 	@Test
-	public void executesQueryMethodsCorrectly() {
+	void executesQueryMethodsCorrectly() {
 		City city = this.cityRepository
 				.findAll(PageRequest.of(0, 1, Direction.ASC, "name")).getContent().get(0);
 		assertThat(city.getName()).isEqualTo("Atlanta");