chore: Migrate Junit 4 to Junit 5 for showcase (#2757)

fixes #2728, attempt to remove Junit 4 support after migration.
Other than POM dependency migrate, changes include:
- package name changes
- Junit 5 syntax upgrades, e.g. `@Before` --> `@BeforeEach`, Replace
assertion methods
- remove public modifier on tests and test classes.
- Refactor JUnit 4 TemporaryFolder `@Rule` in
[ITGdch.java](https://github.com/googleapis/sdk-platform-java/pull/2757/files#diff-6ae7755a0b038e1a2febae2d27e36c762f6751b8c7db577421667069399884b4)
to JUnit 5 `@TempDir`
- Replace `@Test(timeout = 15000L)` in
[ITClientShutdown.java](https://github.com/googleapis/sdk-platform-java/pull/2757/files#diff-70d1df57471178a7a63302f82e4a4855ffbbd642ea67d92d501bd1f7008957ca)
with `@Timeout(15)`
- Update `@RunWith(Parameterized.class)` test in
[ITHttpAnnotation.java](https://github.com/googleapis/sdk-platform-java/pull/2757/files#diff-03d420650ecc9fe78ad4887761043c4fdceaa978f464ce30cfc4ed5f8be9b64d)
to `@ParameterizedTest` with `@MethodSource("data")`

~~Note: #2737 creates a new test class with JUnit4 syntax. Depending on
merging order, I will either update in this pr, or #2737.~~ Updated.


Due to truth library depending on junit 4 ([see
issue](google/truth#333)), junit 4 cannot be
completely removed, or will encounter `java.lang.ClassNotFoundException:
org.junit.runner.notification.RunListener` running tests with maven
surefire. To keep things cleaner, excluding the implicitly junit brought
in from truth and `junit-vintage-engine`. We could also do the reverse,
and make a comment if that's prefered.

---------

Co-authored-by: Burke Davison <[email protected]>
Co-authored-by: Lawrence Qiu <[email protected]>

Author: 3 people

showcase/gapic-showcase/pom.xml

@@ -132,14 +132,30 @@
 
     <!-- Test dependencies -->
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.vintage</groupId>
+      <artifactId>junit-vintage-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-params</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>com.google.truth</groupId>
       <artifactId>truth</artifactId>
       <version>1.4.2</version>
+      <exclusions>
+        <exclusion>
+          <groupId>junit</groupId>
+          <artifactId>junit</artifactId>
+        </exclusion>
+      </exclusions>
       <scope>test</scope>
     </dependency>
 

showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITApiVersionHeaders.java

@@ -16,7 +16,7 @@
 package com.google.showcase.v1beta1.it;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import com.google.api.gax.httpjson.*;
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
@@ -31,15 +31,15 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.concurrent.TimeUnit;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
 
 // TODO: add testing on error responses once feat is implemented in showcase.
 //  https://github.com/googleapis/gapic-showcase/pull/1456
 // TODO: watch for showcase gRPC trailer changes suggested in
 // https://github.com/googleapis/gapic-showcase/pull/1509#issuecomment-2089147103
-public class ITApiVersionHeaders {
+class ITApiVersionHeaders {
   private static final String HTTP_RESPONSE_HEADER_STRING =
       "x-showcase-request-" + ApiClientHeaderProvider.API_VERSION_HEADER_KEY;
   private static final Metadata.Key<String> API_VERSION_HEADER_KEY =
@@ -51,7 +51,6 @@ public class ITApiVersionHeaders {
   private static final String EXPECTED_EXCEPTION_MESSAGE =
       "Header provider can't override the header: "
           + ApiClientHeaderProvider.API_VERSION_HEADER_KEY;
-  private static final int DEFAULT_AWAIT_TERMINATION_SEC = 10;
 
   // Implement a client interceptor to retrieve the trailing metadata from response.
   private static class GrpcCapturingClientInterceptor implements ClientInterceptor {
@@ -149,17 +148,17 @@ public void onClose(int statusCode, HttpJsonMetadata trailers) {
     }
   }
 
-  private HttpJsonCapturingClientInterceptor httpJsonInterceptor;
-  private GrpcCapturingClientInterceptor grpcInterceptor;
-  private HttpJsonCapturingClientInterceptor httpJsonComplianceInterceptor;
-  private GrpcCapturingClientInterceptor grpcComplianceInterceptor;
-  private EchoClient grpcClient;
-  private EchoClient httpJsonClient;
-  private ComplianceClient grpcComplianceClient;
-  private ComplianceClient httpJsonComplianceClient;
-
-  @Before
-  public void createClients() throws Exception {
+  private static HttpJsonCapturingClientInterceptor httpJsonInterceptor;
+  private static GrpcCapturingClientInterceptor grpcInterceptor;
+  private static HttpJsonCapturingClientInterceptor httpJsonComplianceInterceptor;
+  private static GrpcCapturingClientInterceptor grpcComplianceInterceptor;
+  private static EchoClient grpcClient;
+  private static EchoClient httpJsonClient;
+  private static ComplianceClient grpcComplianceClient;
+  private static ComplianceClient httpJsonComplianceClient;
+
+  @BeforeAll
+  static void createClients() throws Exception {
     // Create gRPC Interceptor and Client
     grpcInterceptor = new GrpcCapturingClientInterceptor();
     grpcClient = TestClientInitializer.createGrpcEchoClient(ImmutableList.of(grpcInterceptor));
@@ -183,28 +182,31 @@ public void createClients() throws Exception {
             ImmutableList.of(httpJsonComplianceInterceptor));
   }
 
-  @After
-  public void destroyClient() throws InterruptedException {
+  @AfterAll
+  static void destroyClient() throws InterruptedException {
     grpcClient.close();
     httpJsonClient.close();
     grpcComplianceClient.close();
     httpJsonComplianceClient.close();
 
-    grpcClient.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
-    httpJsonClient.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
-    grpcComplianceClient.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
-    httpJsonComplianceClient.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
+    grpcClient.awaitTermination(TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
+    httpJsonClient.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
+    grpcComplianceClient.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
+    httpJsonComplianceClient.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
   }
 
   @Test
-  public void testGrpc_matchesApiVersion() {
+  void testGrpc_matchesApiVersion() {
     grpcClient.echo(EchoRequest.newBuilder().build());
     String headerValue = grpcInterceptor.metadata.get(API_VERSION_HEADER_KEY);
     assertThat(headerValue).isEqualTo(EXPECTED_ECHO_API_VERSION);
   }
 
   @Test
-  public void testHttpJson_matchesHeaderName() {
+  void testHttpJson_matchesHeaderName() {
     httpJsonClient.echo(EchoRequest.newBuilder().build());
     ArrayList headerValues =
         (ArrayList) httpJsonInterceptor.metadata.getHeaders().get(HTTP_RESPONSE_HEADER_STRING);
@@ -213,15 +215,15 @@ public void testHttpJson_matchesHeaderName() {
   }
 
   @Test
-  public void testGrpc_noApiVersion() {
+  void testGrpc_noApiVersion() {
     RepeatRequest request =
         RepeatRequest.newBuilder().setInfo(ComplianceData.newBuilder().setFString("test")).build();
     grpcComplianceClient.repeatDataSimplePath(request);
     assertThat(API_VERSION_HEADER_KEY).isNotIn(grpcComplianceInterceptor.metadata.keys());
   }
 
   @Test
-  public void testHttpJson_noApiVersion() {
+  void testHttpJson_noApiVersion() {
     RepeatRequest request =
         RepeatRequest.newBuilder().setInfo(ComplianceData.newBuilder().setFString("test")).build();
     httpJsonComplianceClient.repeatDataSimplePath(request);
@@ -230,7 +232,7 @@ public void testHttpJson_noApiVersion() {
   }
 
   @Test
-  public void testGrpcEcho_userApiVersionThrowsException() throws IOException {
+  void testGrpcEcho_userApiVersionThrowsException() throws IOException {
     StubSettings stubSettings =
         grpcClient
             .getSettings()
@@ -249,7 +251,7 @@ public void testGrpcEcho_userApiVersionThrowsException() throws IOException {
   }
 
   @Test
-  public void testHttpJsonEcho_userApiVersionThrowsException() throws IOException {
+  void testHttpJsonEcho_userApiVersionThrowsException() throws IOException {
     StubSettings stubSettings =
         httpJsonClient
             .getSettings()
@@ -268,7 +270,7 @@ public void testHttpJsonEcho_userApiVersionThrowsException() throws IOException
   }
 
   @Test
-  public void testGrpcCompliance_userApiVersionSetSuccess() throws IOException {
+  void testGrpcCompliance_userApiVersionSetSuccess() throws IOException {
     StubSettings stubSettingsWithApiVersionHeader =
         grpcComplianceClient
             .getSettings()
@@ -293,7 +295,7 @@ public void testGrpcCompliance_userApiVersionSetSuccess() throws IOException {
   }
 
   @Test
-  public void testHttpJsonCompliance_userApiVersionSetSuccess() throws IOException {
+  void testHttpJsonCompliance_userApiVersionSetSuccess() throws IOException {
     StubSettings httpJsonStubSettingsWithApiVersionHeader =
         httpJsonComplianceClient
             .getSettings()

showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITAutoPopulatedFields.java

@@ -15,7 +15,7 @@
  */
 package com.google.showcase.v1beta1.it;
 
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import com.google.api.gax.httpjson.ApiMethodDescriptor;
 import com.google.api.gax.httpjson.ForwardingHttpJsonClientCall;
@@ -47,12 +47,12 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.threeten.bp.Duration;
 
-public class ITAutoPopulatedFields {
+class ITAutoPopulatedFields {
 
   private static class HttpJsonInterceptor implements HttpJsonClientInterceptor {
     private Consumer<Object> onRequestIntercepted;
@@ -120,8 +120,8 @@ public void sendMessage(ReqT message) {
   private EchoClient httpJsonClient;
   private EchoClient httpJsonClientWithRetries;
 
-  @Before
-  public void createClients() throws Exception {
+  @BeforeEach
+  void createClients() throws Exception {
     RetrySettings defaultRetrySettings =
         RetrySettings.newBuilder()
             .setInitialRpcTimeout(Duration.ofMillis(5000L))
@@ -156,15 +156,22 @@ public void createClients() throws Exception {
             defaultRetrySettings, retryableCodes, ImmutableList.of(httpJsonInterceptor));
   }
 
-  @After
-  public void destroyClient() {
+  @AfterEach
+  void destroyClient() throws InterruptedException {
     grpcClientWithoutRetries.close();
     grpcClientWithRetries.close();
     httpJsonClient.close();
+
+    grpcClientWithoutRetries.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
+    grpcClientWithRetries.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
+    httpJsonClient.awaitTermination(
+        TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
   }
 
   @Test
-  public void testGrpc_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
+  void testGrpc_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
     List<String> capturedRequestIds = new ArrayList<>();
     grpcRequestInterceptor.setOnRequestIntercepted(
         request -> {
@@ -181,7 +188,7 @@ public void testGrpc_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
   }
 
   @Test
-  public void testGrpc_shouldNotAutoPopulateRequestIdIfSetInRequest() {
+  void testGrpc_shouldNotAutoPopulateRequestIdIfSetInRequest() {
     List<String> capturedRequestIds = new ArrayList<>();
     grpcRequestInterceptor.setOnRequestIntercepted(
         request -> {
@@ -197,7 +204,7 @@ public void testGrpc_shouldNotAutoPopulateRequestIdIfSetInRequest() {
   }
 
   @Test
-  public void testHttpJson_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
+  void testHttpJson_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
     List<String> capturedRequestIds = new ArrayList<>();
     httpJsonInterceptor.setOnRequestIntercepted(
         request -> {
@@ -214,7 +221,7 @@ public void testHttpJson_autoPopulateRequestIdWhenAttemptedOnceSuccessfully() {
   }
 
   @Test
-  public void testHttpJson_shouldNotAutoPopulateRequestIdIfSetInRequest() {
+  void testHttpJson_shouldNotAutoPopulateRequestIdIfSetInRequest() {
     String UUIDsent = UUID.randomUUID().toString();
     List<String> capturedRequestIds = new ArrayList<>();
     httpJsonInterceptor.setOnRequestIntercepted(
@@ -230,7 +237,7 @@ public void testHttpJson_shouldNotAutoPopulateRequestIdIfSetInRequest() {
   }
 
   @Test
-  public void testGRPC_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried() throws Exception {
+  void testGRPC_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried() throws Exception {
     List<String> capturedRequestIds = new ArrayList<>();
     grpcRequestInterceptor.setOnRequestIntercepted(
         request -> {
@@ -264,7 +271,7 @@ public void testGRPC_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried() thr
   }
 
   @Test
-  public void testGRPC_setsSameAutoPopulatedRequestIdWhenRequestsAreRetried() throws Exception {
+  void testGRPC_setsSameAutoPopulatedRequestIdWhenRequestsAreRetried() throws Exception {
     List<String> capturedRequestIds = new ArrayList<>();
     grpcRequestInterceptor.setOnRequestIntercepted(
         request -> {
@@ -302,8 +309,7 @@ public void testGRPC_setsSameAutoPopulatedRequestIdWhenRequestsAreRetried() thro
   }
 
   @Test
-  public void testHttpJson_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried()
-      throws Exception {
+  void testHttpJson_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried() throws Exception {
     List<String> capturedRequestIds = new ArrayList<>();
     httpJsonInterceptor.setOnRequestIntercepted(
         request -> {
@@ -336,7 +342,7 @@ public void testHttpJson_setsSameRequestIdIfSetInRequestWhenRequestsAreRetried()
   }
 
   @Test
-  public void testHttpJson_setsSameAutoPopulatedRequestIdWhenRequestsAreRetried() throws Exception {
+  void testHttpJson_setsSameAutoPopulatedRequestIdWhenRequestsAreRetried() throws Exception {
     List<String> capturedRequestIds = new ArrayList<>();
     httpJsonInterceptor.setOnRequestIntercepted(
         request -> {

showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITBidiStreaming.java

@@ -30,22 +30,22 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
 
-public class ITBidiStreaming {
+class ITBidiStreaming {
 
   private static EchoClient grpcClient;
 
-  @BeforeClass
-  public static void createClients() throws Exception {
+  @BeforeAll
+  static void createClients() throws Exception {
     // Create gRPC Echo Client
     grpcClient = TestClientInitializer.createGrpcEchoClient();
   }
 
-  @AfterClass
-  public static void destroyClients() throws Exception {
+  @AfterAll
+  static void destroyClients() throws Exception {
     grpcClient.close();
     grpcClient.awaitTermination(TestClientInitializer.AWAIT_TERMINATION_SECONDS, TimeUnit.SECONDS);
   }
@@ -57,7 +57,7 @@ public static void destroyClients() throws Exception {
   // three requests, respond twice for every request etc. If that happens, the response content may
   // not be exactly the same as request content.
   @Test
-  public void testGrpc_splitCall_shouldListensToResponse() throws Exception {
+  void testGrpc_splitCall_shouldListensToResponse() throws Exception {
     // given
     List<String> expected = Arrays.asList("The rain in Spain stays mainly on the plain".split(" "));
     TestResponseObserver responseObserver = new TestResponseObserver();