Add unit test for composeability of nodes

system_metrics_collector/CMakeLists.txt

@@ -78,6 +78,7 @@ ament_target_dependencies(linux_memory_collector)
 if(BUILD_TESTING)
   find_package(ament_lint_auto REQUIRED)
   find_package(ament_cmake_gtest REQUIRED)
+  find_package(class_loader REQUIRED)
   find_package(lifecycle_msgs REQUIRED)
 
   ament_lint_auto_find_test_dependencies()
@@ -122,6 +123,10 @@ if(BUILD_TESTING)
   target_link_libraries(test_periodic_measurement_node system_metrics_collector)
   ament_target_dependencies(test_periodic_measurement_node lifecycle_msgs metrics_statistics_msgs rclcpp)
 
+  ament_add_gtest(test_composition
+          test/system_metrics_collector/test_composition.cpp)
+  ament_target_dependencies(test_composition class_loader rclcpp rclcpp_components)
+
   ament_add_gtest(test_utilities
           test/system_metrics_collector/test_utilities.cpp)
   target_link_libraries(test_utilities system_metrics_collector)

system_metrics_collector/package.xml

@@ -26,6 +26,7 @@
   <test_depend>ament_cmake_gtest</test_depend>
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
+  <test_depend>class_loader</test_depend>
   <test_depend>lifecycle_msgs</test_depend>
   <test_depend>rclcpp</test_depend>
   <test_depend>rclcpp_components</test_depend>

system_metrics_collector/test/system_metrics_collector/test_composition.cpp

@@ -0,0 +1,72 @@
+// Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// 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 <gtest/gtest.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "class_loader/class_loader.hpp"
+#include "rclcpp/rclcpp.hpp"
+#include "rclcpp_components/node_factory.hpp"
+
+#include "test_constants.hpp"
+
+namespace
+{
+constexpr const char kSystemMetricsCollectorLibName[] = "libsystem_metrics_collector.so";
+constexpr const std::array<const char *, 2> kExpectedClassNames = {
+  "system_metrics_collector::LinuxProcessCpuMeasurementNode",
+  "system_metrics_collector::LinuxProcessMemoryMeasurementNode"
+};
+}
+
+bool IsExpectedClassName(const std::string & class_name)
+{
+  auto result = std::find_if(kExpectedClassNames.cbegin(), kExpectedClassNames.cend(),
+      [&class_name](const char * expected_class_name) {
+        return class_name.find(expected_class_name) != std::string::npos;
+      });
+  return result != kExpectedClassNames.cend();
+}
+
+TEST(TestComposeableNodes, DlopenTest)
+{
+  rclcpp::init(0, nullptr);
+  rclcpp::executors::SingleThreadedExecutor exec;
+  rclcpp::NodeOptions options;
+
+  const auto loader = std::make_unique<class_loader::ClassLoader>(kSystemMetricsCollectorLibName);
+  const auto class_names = loader->getAvailableClasses<rclcpp_components::NodeFactory>();
+  ASSERT_EQ(kExpectedClassNames.size(), class_names.size());
+
+  std::vector<rclcpp_components::NodeInstanceWrapper> node_wrappers;
+  for (const auto & class_name : class_names) {
+    ASSERT_TRUE(IsExpectedClassName(class_name));
+    const auto node_factory = loader->createInstance<rclcpp_components::NodeFactory>(class_name);
+    auto wrapper = node_factory->create_node_instance(options);
+    exec.add_node(wrapper.get_node_base_interface());
+    node_wrappers.push_back(wrapper);
+  }
+
+  std::promise<bool> empty_promise;
+  std::shared_future<bool> dummy_future = empty_promise.get_future();
+  exec.spin_until_future_complete(dummy_future, test_constants::kTestDuration);
+
+  for (auto & wrapper : node_wrappers) {
+    exec.remove_node(wrapper.get_node_base_interface());
+  }
+  rclcpp::shutdown();
+}