ROS2 package demo 3 - lint and gtest

The goal for today is to get linting working on the repo, then divide the repo into .cpp and .hpp and add some documentation.

Linting

Hey, a really great post about this on ROS answers!

I really need a way to search over some core ROS2 code for examples. Let me clone a few repos and add them to a VS Code workspace. Which ones?

• ros2
• rclcpp
• common_interfaces
• rcl_logging
• geometry2
• message_filters
• ros_testing
• moveit2
• ros-controls/ros2_controls

Searching for “if(BUILD_TESTING)” shows lots of variants. “ament_lint_auto” is common. Checking its docs it seems pretty straightforward. I’ll try it.

Hmmm, seem to already have this in CMakeLists.txt How about package.xml? Yes. So I can run colcon test. Do it, shows running test, output shows “with test failures” but noe listed. What gives? Where is stderr? This colcon issue gave me this suggestion which works: colcon test-result --verbose But why isn’t that in the log? … OK I see, I was looking in the wrong directory

So I did not have to make any changes, and I am getting lint errors! Trying to fix them.

One problem I cannot fix: it wants the header hard to be FQDEMO__DUMMY_HPP_ but I think it should me FQDEMO_NODES__DUMMY_HPP_ Why? check is done in ament_cpplint.main, going to modify that and see if I can figure out why. OK I see, wrong subdirectory name: include/fqdemo instead of include/fqdemo_nodes

Success!

separate .hpp

First, I have to make a legit .hpp for the file. I need something with a node. Looking at https://github.com/ros2/demos/blob/master/logging_demo/include/logging_demo/logger_usage_component.hpp then some others. Amazingly hard to find a simple node example. Finally pieced it together and pushed the changes.

gtest

sensor_msgs pack kage has a simple implementation of this. I’ll use that as an example and implement. No, that had no node. Took a lot of searching to figure it out, kep getting linking problems. I ended up make a project library that is used by the test.

Anyway, now I have a successfully testing repo with lint and gtest. Checking in.

Next steps

I’d like to do an integration test to confirm node message processing. See here for how to do that.