Add subscription callback test with ping+pong nodes

tracetools_test/src/test_ping.cpp

@@ -0,0 +1,62 @@
+#include <memory>
+#include <chrono>
+
+#include "rclcpp/rclcpp.hpp"
+#include "rclcpp/rate.hpp"
+#include "std_msgs/msg/string.hpp"
+
+using namespace std::chrono_literals;
+
+
+class PingNode : public rclcpp::Node
+{
+public:
+    PingNode(rclcpp::NodeOptions options) : Node("ping_node", options)
+    {
+        sub_ = this->create_subscription<std_msgs::msg::String>(
+            "pong",
+            rclcpp::QoS(10),
+            std::bind(&PingNode::callback, this, std::placeholders::_1));
+        pub_ = this->create_publisher<std_msgs::msg::String>(
+            "ping",
+            rclcpp::QoS(10));
+        timer_ = this->create_wall_timer(
+            500ms,
+            std::bind(&PingNode::timer_callback, this));
+    }
+
+
+private:
+    void callback(const std_msgs::msg::String::SharedPtr msg)
+    {
+        RCLCPP_INFO(this->get_logger(), "[output] %s", msg->data.c_str());
+        rclcpp::shutdown();
+    }
+
+    void timer_callback()
+    {
+        auto msg = std::make_shared<std_msgs::msg::String>();
+        msg->data = "some random ping string";
+        pub_->publish(*msg);
+    }
+
+    rclcpp::Subscription<std_msgs::msg::String>::SharedPtr sub_;
+    rclcpp::Publisher<std_msgs::msg::String>::SharedPtr pub_;
+    rclcpp::TimerBase::SharedPtr timer_;
+};
+
+int main(int argc, char* argv[])
+{
+    rclcpp::init(argc, argv);
+
+    rclcpp::executors::SingleThreadedExecutor exec;
+    auto ping_node = std::make_shared<PingNode>(rclcpp::NodeOptions());
+    exec.add_node(ping_node);
+
+    printf("spinning\n");
+    exec.spin();
+
+    // Will actually be called inside the node's callback
+    rclcpp::shutdown();
+    return 0;
+}