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-jdbc/src/test/java/sample/data/jdbc/CustomerRepositoryIntegrationTests.java

@@ -15,13 +15,11 @@
  */
 package sample.data.jdbc;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.test.context.junit4.SpringRunner;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -30,26 +28,25 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Andy Wilkinson
  */
-@RunWith(SpringRunner.class)
 @SpringBootTest
 @AutoConfigureTestDatabase
-public class CustomerRepositoryIntegrationTests {
+class CustomerRepositoryIntegrationTests {
 
 	@Autowired
 	private CustomerRepository repository;
 
 	@Test
-	public void findAllCustomers() {
+	void findAllCustomers() {
 		assertThat(this.repository.findAll()).hasSize(2);
 	}
 
 	@Test
-	public void findByNameWithMatch() {
+	void findByNameWithMatch() {
 		assertThat(this.repository.findByName("joan")).hasSize(1);
 	}
 
 	@Test
-	public void findByNameWithNoMatch() {
+	void findByNameWithNoMatch() {
 		assertThat(this.repository.findByName("hugh")).isEmpty();
 	}
 

spring-boot-samples/spring-boot-sample-data-jdbc/src/test/java/sample/data/jdbc/SampleDataJdbcApplicationTests.java

@@ -16,13 +16,11 @@
 
 package sample.data.jdbc;
 
-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;
@@ -37,22 +35,21 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  *
  * @author Andy Wilkinson
  */
-@RunWith(SpringRunner.class)
 @SpringBootTest
-public class SampleDataJdbcApplicationTests {
+class SampleDataJdbcApplicationTests {
 
 	@Autowired
 	private WebApplicationContext context;
 
 	private MockMvc mvc;
 
-	@Before
+	@BeforeEach
 	public void setUp() {
 		this.mvc = MockMvcBuilders.webAppContextSetup(this.context).build();
 	}
 
 	@Test
-	public void testCustomers() throws Exception {
+	void testCustomers() throws Exception {
 		this.mvc.perform(get("/").param("name", "merEDith")).andExpect(status().isOk())
 				.andExpect(content().string(containsString("Meredith")));
 	}