made junit5 default test generation framework (#1320)

fixes #1249

samples/standalone/webclient/http-server/build.gradle

@@ -29,7 +29,9 @@ dependencies {
 	implementation("org.springframework.boot:spring-boot-starter-webflux")
 	implementation("org.springframework.boot:spring-boot-starter-actuator")
 
-	testImplementation 'org.springframework.boot:spring-boot-starter-test'
+	testImplementation('org.springframework.boot:spring-boot-starter-test') {
+		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
+	}
 	testImplementation 'org.springframework.restdocs:spring-restdocs-webtestclient'
 	testImplementation 'org.springframework.cloud:spring-cloud-contract-wiremock'
 }
@@ -39,6 +41,7 @@ contracts {
 }
 
 test {
+	useJUnitPlatform()
 	systemProperty 'spring.profiles.active', 'gradle'
 	testLogging {
 		exceptionFormat = 'full'

samples/standalone/webclient/http-server/pom.xml

@@ -38,6 +38,12 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
 		</dependency>
 
 		<dependency>

samples/standalone/webclient/http-server/src/test/java/com/example/fraud/StubGeneratorTests.java

@@ -20,9 +20,9 @@ import java.math.BigDecimal;
 
 import com.example.fraud.model.FraudCheck;
 import com.fasterxml.jackson.databind.ObjectMapper;
-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.autoconfigure.json.AutoConfigureJsonTesters;
@@ -32,13 +32,13 @@ import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.json.JacksonTester;
 import org.springframework.http.MediaType;
 import org.springframework.restdocs.webtestclient.WebTestClientRestDocumentation;
-import org.springframework.test.context.junit4.SpringRunner;
+
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.web.reactive.function.BodyInserters;
 
 import static org.springframework.cloud.contract.wiremock.restdocs.WireMockWebTestClient.verify;
 
-@RunWith(SpringRunner.class)
+
 @SpringBootTest(classes = Application.class)
 @AutoConfigureRestDocs(outputDir = "target/snippets")
 @AutoConfigureWebTestClient
@@ -50,7 +50,7 @@ public class StubGeneratorTests {
 
 	private JacksonTester<FraudCheck> json;
 
-	@Before
+	@BeforeEach
 	public void setup() {
 		ObjectMapper objectMappper = new ObjectMapper();
 		// Possibly configure the mapper