Zenoh: add INTEGRATION_twoProcsSrvCallLateResponder test

Generated-by: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: Carlos Aguero <caguero@honurobotics.com>

Author: caguero

test/integration/CMakeLists.txt

@@ -8,6 +8,7 @@ set(tests
   twoProcsPubSub.cc
   twoProcsPubSubStats.cc
   twoProcsSrvCall.cc
+  twoProcsSrvCallLateResponder.cc
   twoProcsSrvCallStress.cc
   twoProcsSrvCallSync1.cc
   twoProcsSrvCallWithoutInput.cc

test/integration/twoProcsSrvCallLateResponder.cc

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2026 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+#include <gz/msgs/int32.pb.h>
+
+#include <chrono>
+#include <memory>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "gz/transport/Node.hh"
+
+#include <gz/utils/Environment.hh>
+#include "gz/utils/Subprocess.hh"
+
+#include "gtest/gtest.h"
+#include "test_config.hh"
+#include "test_utils.hh"
+
+using namespace gz;
+
+static constexpr const char *g_topic = "/foo";
+static constexpr int g_data = 5;
+
+//////////////////////////////////////////////////
+/// \brief Fixture that does NOT spawn the responder in SetUp.
+/// The test body opens a Node first and only then spawns the
+/// replier, exercising the cold-start path where a request is
+/// issued before the responder's queryable has been declared.
+class twoProcSrvCallLateResponder : public testing::Test {
+ protected:
+  void SetUp() override {
+    gz::utils::env("GZ_PARTITION", this->prevPartition);
+    this->partition = testing::getRandomNumber();
+    gz::utils::setenv("GZ_PARTITION", this->partition);
+    // Note: do NOT spawn the replier yet.
+  }
+
+  void TearDown() override {
+    if (this->replier)
+    {
+      this->replier->Terminate();
+      this->replier->Join();
+    }
+    gz::utils::setenv("GZ_PARTITION", this->prevPartition);
+  }
+
+  /// \brief Spawn the replier. Typically called from a worker
+  /// thread after the requester has issued a blocking Request.
+  void SpawnReplier() {
+    this->replier = std::make_unique<gz::utils::Subprocess>(
+      std::vector<std::string>(
+        {test_executables::kTwoProcsSrvCallReplier, this->partition}));
+  }
+
+ private:
+  std::string prevPartition;
+  std::string partition;
+  std::unique_ptr<gz::utils::Subprocess> replier;
+};
+
+//////////////////////////////////////////////////
+TEST_F(twoProcSrvCallLateResponder, RequestSucceedsWhenResponderAppearsLate)
+{
+  // Open the requester Node before the responder process exists.
+  // The persistent Querier declares interest on /foo immediately;
+  // once the responder is spawned, it sees the interest and
+  // propagates its queryable so the in-flight request finds it.
+  transport::Node node;
+
+  // Spawn the replier from a worker thread 500 ms after we begin
+  // the synchronous Request below. 500 ms is well inside the 5 s
+  // request timeout, so a working request/reply path should
+  // comfortably succeed within budget.
+  std::thread spawner([this]()
+  {
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    this->SpawnReplier();
+  });
+
+  msgs::Int32 req;
+  req.set_data(g_data);
+  msgs::Int32 rep;
+  bool result = false;
+  const unsigned int timeoutMs = 5000;
+
+  const bool executed = node.Request(g_topic, req, timeoutMs, rep, result);
+
+  if (spawner.joinable())
+    spawner.join();
+
+  EXPECT_TRUE(executed)
+    << "Request did not complete within " << timeoutMs << "ms after the "
+    << "late responder start";
+  EXPECT_TRUE(result) << "responder returned a failure result";
+  EXPECT_EQ(rep.data(), g_data);
+}