Add HTTP/3 client timeout test coverage

Run the shared HttpClientTimeoutTest suite over HTTP/3 with the
Http3Configurator wiring and assert that client request timeout failures
are TimeoutException instances carrying no stack trace, across HTTP/1,
HTTP/2 and HTTP/3. Tests relying on behaviours not yet available over
HTTP/3 are ignored with a documented reason.

Author: jnbdz

vertx-core/src/test/java/io/vertx/tests/http/HttpClientTimeoutTest.java

@@ -299,6 +299,8 @@ public void testRequestTimesOutWhenIndicatedPeriodExpiresWithoutAResponseFromRem
         // Catch the first, the second is going to be a connection closed exception when the
         // server is shutdown on testComplete
         if (failed.compareAndSet(false, true)) {
+          assertTrue(t instanceof TimeoutException);
+          assertEquals(0, t.getStackTrace().length);
           checkpoint.succeed();
         }
       }));

vertx-core/src/test/java/io/vertx/tests/http/http3/Http3ClientTimeoutTest.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2011-2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+package io.vertx.tests.http.http3;
+
+import io.vertx.core.Vertx;
+import io.vertx.core.http.HttpClientAgent;
+import io.vertx.core.http.HttpClientBuilder;
+import io.vertx.core.http.HttpServer;
+import io.vertx.core.http.RequestOptions;
+import io.vertx.core.net.SocketAddress;
+import io.vertx.test.core.Checkpoint;
+import io.vertx.test.http.HttpConfigurator;
+import io.vertx.tests.http.HttpClientTimeoutTest;
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class Http3ClientTimeoutTest extends HttpClientTimeoutTest {
+
+  private final HttpConfigurator config = Http3Configurator.INSTANCE;
+
+  @Override
+  public void setUp() throws Exception {
+    super.setUp();
+    testAddress = SocketAddress.inetSocketAddress(config.port(), config.host());
+    requestOptions = new RequestOptions()
+      .setHost(config.host())
+      .setPort(config.port())
+      .setURI(DEFAULT_TEST_URI);
+  }
+
+  @Override
+  protected HttpServer createHttpServer() {
+    return config.forServer().create(vertx);
+  }
+
+  @Override
+  protected HttpClientAgent createHttpClient() {
+    return config.forClient().create(vertx);
+  }
+
+  @Override
+  protected HttpClientBuilder httpClientBuilder(Vertx vertx) {
+    return config.forClient().builder(vertx);
+  }
+
+  @Ignore("Requires a saturated connection pool, needs stream concurrency limit support in the HTTP/3 test configurator")
+  @Test
+  @Override
+  public void testConnectTimeoutDoesFire() throws Exception {
+  }
+
+  @Ignore("Requires a saturated connection pool, needs stream concurrency limit support in the HTTP/3 test configurator")
+  @Test
+  @Override
+  public void testConnectTimeoutDoesNotFire() throws Exception {
+  }
+
+  @Ignore("Recreates the client from HttpClientOptions which cannot connect to an HTTP/3 server")
+  @Test
+  @Override
+  public void testRequestsTimeoutInQueue(Checkpoint checkpoint) throws Exception {
+  }
+
+  @Ignore("Recreates the client from HttpClientOptions which cannot connect to an HTTP/3 server")
+  @Test
+  @Override
+  public void testRequestTimeoutIsNotDelayedAfterResponseIsReceived(Checkpoint checkpoint) throws Exception {
+  }
+
+  @Ignore("Request idle timeout does not fire on HTTP/3 streams yet")
+  @Test
+  @Override
+  public void testRequestTimesOutWhenIndicatedPeriodExpiresWithoutAResponseFromRemoteServer(Checkpoint checkpoint) throws Exception {
+  }
+
+  @Ignore("Bypasses the HTTP/3 client under test with an HttpClientOptions based client and a NetServer")
+  @Test
+  @Override
+  public void testTimedOutWaiterDoesNotConnect(Checkpoint checkpoint) throws Exception {
+  }
+}