Fix start_type_description_service param handling (#2897)

roncapat · web-flow · commit 4fb558ae7b2c · 2025-07-16T15:45:44.000-07:00
* Fix `start_type_description_service` param handling

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;

* Add test

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;

* Demonstrate different exceptions depending on node options

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;

* Same exact exception and `what()` message in both cases

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;

* Uncrustify

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;

---------

Signed-off-by: Patrick Roncagliolo &lt;ronca.pat@gmail.com&gt;
diff --git a/rclcpp/src/rclcpp/node_interfaces/node_type_descriptions.cpp b/rclcpp/src/rclcpp/node_interfaces/node_type_descriptions.cpp
@@ -65,25 +65,33 @@ class NodeTypeDescriptions::NodeTypeDescriptionsImpl
   : logger_(node_logging->get_logger()),
     node_base_(node_base)
   {
+    rclcpp::ParameterValue enable_param;
     const std::string enable_param_name = "start_type_description_service";
 
-    bool enabled = false;
-    try {
-      auto enable_param = node_parameters->declare_parameter(
+    if (!node_parameters->has_parameter(enable_param_name)) {
+      enable_param = node_parameters->declare_parameter(
         enable_param_name,
         rclcpp::ParameterValue(true),
         rcl_interfaces::msg::ParameterDescriptor()
         .set__name(enable_param_name)
         .set__type(rclcpp::PARAMETER_BOOL)
         .set__description("Start the ~/get_type_description service for this node.")
         .set__read_only(true));
-      enabled = enable_param.get<bool>();
-    } catch (const rclcpp::exceptions::InvalidParameterTypeException & exc) {
-      RCLCPP_ERROR(logger_, "%s", exc.what());
-      throw;
+    } else {
+      enable_param = node_parameters->get_parameter(enable_param_name).get_parameter_value();
+    }
+    if (enable_param.get_type() != rclcpp::PARAMETER_BOOL) {
+      RCLCPP_ERROR(
+        logger_,
+            "Invalid type '%s' for parameter 'start_type_description_service', should be 'bool'",
+        rclcpp::to_string(enable_param.get_type()).c_str());
+      std::ostringstream ss;
+      ss << "Wrong parameter type, parameter {" << enable_param_name << "} is of type {bool}, "
+         << "setting it to {" << to_string(enable_param.get_type()) << "} is not allowed.";
+      throw rclcpp::exceptions::InvalidParameterTypeException(enable_param_name, ss.str());
     }
 
-    if (enabled) {
+    if (enable_param.get<bool>()) {
       auto * rcl_node = node_base->get_rcl_node_handle();
       std::shared_ptr<rcl_service_t> rcl_srv(
         new rcl_service_t,
diff --git a/rclcpp/test/rclcpp/node_interfaces/test_node_type_descriptions.cpp b/rclcpp/test/rclcpp/node_interfaces/test_node_type_descriptions.cpp
@@ -37,6 +37,38 @@ TEST_F(TestNodeTypeDescriptions, interface_created)
   ASSERT_NE(nullptr, node.get_node_type_descriptions_interface());
 }
 
+TEST_F(TestNodeTypeDescriptions, automatically_declare_parameters_from_overrides)
+{
+  rclcpp::NodeOptions node_options;
+  node_options.automatically_declare_parameters_from_overrides(true);
+  node_options.append_parameter_override("start_type_description_service", false);
+  ASSERT_NO_THROW(
+  {
+    auto node = std::make_shared<rclcpp::Node>("node", "ns", node_options);
+    (void) node;
+  });
+}
+
+TEST_F(TestNodeTypeDescriptions, bad_parameter_type)
+{
+  rclcpp::NodeOptions node_options;
+  node_options.append_parameter_override("start_type_description_service", "unexpected_type");
+
+  ASSERT_THROW(
+  {
+    node_options.automatically_declare_parameters_from_overrides(false);
+    auto node = std::make_shared<rclcpp::Node>("node", "ns", node_options);
+    (void) node;
+  }, rclcpp::exceptions::InvalidParameterTypeException);
+
+  ASSERT_THROW(
+  {
+    node_options.automatically_declare_parameters_from_overrides(true);
+    auto node = std::make_shared<rclcpp::Node>("node", "ns", node_options);
+    (void) node;
+  }, rclcpp::exceptions::InvalidParameterTypeException);
+}
+
 TEST_F(TestNodeTypeDescriptions, disabled_no_service)
 {
   rclcpp::NodeOptions node_options;
