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-rest/src/test/java/sample/data/rest/SampleDataRestApplicationTests.java

@@ -16,13 +16,11 @@
 
 package sample.data.rest;
 
-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.junit4.SpringRunner;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.web.context.WebApplicationContext;
@@ -41,29 +39,28 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * @author Oliver Gierke
  * @author Andy Wilkinson
  */
-@RunWith(SpringRunner.class)
 @SpringBootTest
 // Separate profile for web tests to avoid clashing databases
-public class SampleDataRestApplicationTests {
+class SampleDataRestApplicationTests {
 
 	@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("/api")).andExpect(status().isOk())
 				.andExpect(content().string(containsString("hotels")));
 	}
 
 	@Test
-	public void findByNameAndCountry() throws Exception {
+	void findByNameAndCountry() throws Exception {
 		this.mvc.perform(get(
 				"/api/cities/search/findByNameAndCountryAllIgnoringCase?name=Melbourne&country=Australia"))
 				.andExpect(status().isOk())
@@ -72,7 +69,7 @@ public class SampleDataRestApplicationTests {
 	}
 
 	@Test
-	public void findByContaining() throws Exception {
+	void findByContaining() throws Exception {
 		this.mvc.perform(get(
 				"/api/cities/search/findByNameContainingAndCountryContainingAllIgnoringCase?name=&country=UK"))
 				.andExpect(status().isOk())

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

@@ -16,15 +16,13 @@
 
 package sample.data.rest.service;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 import sample.data.rest.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;
 
@@ -34,21 +32,20 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Oliver Gierke
  * @author Andy Wilkinson
  */
-@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);
 	}
 
 	@Test
-	public void findByNameAndCountry() {
+	void findByNameAndCountry() {
 		City city = this.repository.findByNameAndCountryAllIgnoringCase("Melbourne",
 				"Australia");
 		assertThat(city).isNotNull();
@@ -56,7 +53,7 @@ public class CityRepositoryIntegrationTests {
 	}
 
 	@Test
-	public void findContaining() {
+	void findContaining() {
 		Page<City> cities = this.repository
 				.findByNameContainingAndCountryContainingAllIgnoringCase("", "UK",
 						PageRequest.of(0, 10));