Merge apex_launchtest functionality into launch_testing

[hidmic]

This pull request merges functionality from apex_launchtest and apex_launchtest_cmake packages into launch_testing and launch_testing_ament_cmake respectively. Some renaming and style corrections were applied as well.

Additionally, a new package test_launch_testing is introduced to avoid launch_testing from being an ament_cmake type of package.

Connected to #208.

[hidmic]

CI (full run):

• Linux (unrelated rosidl_generator_c linter errors)
• Linux-aarch64 (unrelated rosidl_generator_c linter errors)
• Packaging Linux
• macOS (unrelated rosidl_generator_c linter errors)
• Windows (unrelated rosidl_generator_c linter errors)

[hidmic]

I'll rebase after fixing this on Windows (which I suspect wasn't supported to begin with).

[hidmic]

Alright, all tests are passing but for a few unrelated, known failures! Running a linux packaging job just in case.

[dirk-thomas]

What is the purpose of having the package launch_testing_ament_cmake being separate from launch_testing? Is it only because the exported CMake functions uses ament_add_test?

[hidmic]

Is it only because the exported CMake functions uses ament_add_test?

Basically, yes. According to what we discussed with @wjwwood, the idea is to keep core launch packages as decoupled from ROS 2 and related build systems as possible.

[wjwwood]

Also, to keep launch_testing pure python. It could be used by other pure python things in conjunction with something like pytest without needing any cmake involvement.

[ivanpauno]

I left some comments, but it looks good to me.

About the license, we will only left the APEX copyright on the top of the files, right?
For example in launch_testing/example_processes/exit_code_proc.

[ivanpauno]

I forgot to add, that I'm seeing an error when I locally do:
colcon test --packages-select launch_testing
Error output:

==================================== ERRORS ====================================
ESC[31mESC[1m_________ ERROR collecting test/launch_testing/test_runner_results.py __________ESC[0m
ESC[31mImportError while importing test module '/home/ivanpauno/ros2_ws/src/ros2/launch/launch_testing/test/launch_testing/test_runner_results.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
test/launch_testing/test_runner_results.py:31: in <module>
    import mock
E   ModuleNotFoundError: No module named 'mock'ESC[0m
- generated xml file: /home/ivanpauno/ros2_ws/build/launch_testing/pytest.xml --
!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!
ESC[31mESC[1m=========================== 1 error in 0.29 seconds ============================ESC[0m

It's not finding mock, but maybe it's a local problem in my environment.

[hidmic]

It's not finding mock, but maybe it's a local problem in my environment.

Nope, python3-mock was missing in the package.xml. Don't forget to rosdep install.

About the license, we will only left the APEX copyright on the top of the files, right?

They authored most of it, so yes. We did some changes, not sure if we should add OSRF's too. Maybe @dirk-thomas or @wjwwood know?

[hidmic]

@ivanpauno thank you for the review man! :D

[wjwwood]

It's appropriate to add OSRF to the copyright if we modified in some significant way, though that line is sort of arbitrary and if you don't add it, then it's not the end of the world.

[jacobperron]

I've skimmed through this and it LGTM too!

[hidmic]

Alright, CI failures are unrelated. Can I get another approval after latest changes?