Description
I tried dynmsg to parse config files for controlling a real robot. There does not appear to be an option for it to raise an exception if a message field is missing.
I found this issue to be a dealbreaker, due to safety concerns, and so I will not be using this library.
Testing
On ROS 2 Humble, here is my parsing code.
geometry_msgs::msg::Pose pose;
yaml_string =
"position: {'x': 0.979, 'y': -2.161}"
"orientation: {'x': 0., 'y': 0., 'z': 0., 'w': 1.}";
dynmsg::cpp::yaml_and_typeinfo_to_rosmsg(
dynmsg::cpp::get_type_info({"geometry_msgs", "Pose"}),
yaml_string,
reinterpret_cast<void*>(&pose)
);Expected Behavior
The YAML would fail to be parsed into a geometry_msgs/msg/Pose, because it is missing a field. It would have to be via an exception, because there is no return code in the function interfaces nor in the return struct RosMessage_Cpp.
Actual behavior
It gets parsed into:
position:
x: 0.979000
y: -2.16100
z: 0.00000
orientation:
x: 0.00000
y: 0.00000
z: 0.00000
w: 1.00000
using the default value of zero for the missing position z.
I find this to be incredibly dangerous when controlling a real robot. A typo in the config file that omits a key could fail silently during parsing and then send a robot to an unexpected wrong position.