Testing ROS2 launch files with Python

Launch files are executable system architecture. They deserve tests because small changes can break namespace rules, parameter loading, or process startup.

import launch
import launch_ros.actions

def generate_test_description():
    node = launch_ros.actions.Node(
        package="robot_bringup",
        executable="state_publisher",
        parameters=[{"use_sim_time": True}],
    )

    return launch.LaunchDescription([node]), {"node": node}

I usually pair launch tests with smoke tests in CI so every package proves it can start in a clean container.