Tests

We provide some unit tests for the Slicer ROS module. The unit tests rely on the automatically generated Python wrapper to to test the C++ MRML nodes. These tests assume you’ve installed the default ROS 2 desktop packages and use the turtlesim examples provided with ROS 2.

To test the MRML ROS 2 parameter node, the ROS 2 turtlesim nodes are started in the background so you will see some windows popping up.

To test the subscribers and publishers, the unit tests subscribe and publish to the same topic so we can send and receive from the same node. This also indirectly tests the conversion methods.

Finally, for TF2 lookups and broadcasts, we use the strategy used to test the subscribers and publishers. The test broadcasts a known transform and uses a lookup to retrieve the value of the TF2 buffer.

Running the unit tests

Using the test wrapper script

The easiest way to run all Python unit tests is to use the provided wrapper script. This script launches Slicer, automatically triggers the test suite, and leaves Slicer open afterwards so you can inspect the Python Console or GUI state:

source ~/ros2_ws/install/setup.bash
ros2 run slicer_ros2_module test

Interactive (Within Slicer)

You can run the tests interactively inside Slicer by opening the Python Console (Ctrl+3) and running:

tests = slicer.util.getModuleLogic('ROS2Tests')
tests.run()

The tests intentionally attempt to perform commands that should fail, so you will see some warning and error messages displayed in the Slicer Python Console.