Expose '--ctest-pytest-with-coverage' option

[christophebedard]

This exposes a --ctest-pytest-with-coverage option for 'cmake' packages. The intent is to use this to generate coverage information for pytest tests with CMake.

Related to ament/ament_cmake#226

[dirk-thomas]

Since this option is not applicable to all CMake packages but only ROS/ament CMake packages this should be added to colcon-ros instead.

Before updating this I would recommend to wait for the feedback on ament/ament_cmake#226 to settle. Maybe the best way would be to set the to-be-created CMake option if the existing argument --pytest-with-coverage is set?

[christophebedard]

Since this option is not applicable to all CMake packages but only ROS/ament CMake packages this should be added to colcon-ros instead.

Makes sense!

Before updating this I would recommend to wait for the feedback on ament/ament_cmake#226 to settle.

Will do.

Maybe the best way would be to set the to-be-created CMake option if the existing argument --pytest-with-coverage is set?

Correct me if I'm wrong, but what you're suggesting over in ament/ament_cmake#226 (comment) is to use a CMake option(...), which needs to be set at build time, while that existing --pytest-with-coverage flag is used when testing (colcon test).

If the above is correct, yes, a similar flag for colcon build makes sense.

[christophebedard]

I'm going to close this in favour of colcon/colcon-ros#101. Feel free to keep the discussion here or just move it there.