Testing: hotfix to recover test coverage CI

[MaEtUgR]

Describe problem solved by the proposed pull request
CMAKE_TESTING should automatically be enabled but I hoped to do that in the test.cmake target specific options and not in the main CMakeLists. I have to see if I can reorder to have a nicer separation working. Here the hotfix to make CI work again.

Test data / coverage
I tested locally if it properly configures make tests as well as make px4_sitl_test test_results_junit used by CI.

Additional context
https://codecov.io/gh/PX4/Firmware/
@dagar informed me about CI coverage builds failing:
e.g. http://ci.px4.io:8080/blue/organizations/jenkins/PX4_misc%2FFirmware-SITL_tests_coverage/detail/master/310/pipeline/
after #11573 was merged. This was not caught by CI running on the PR because there are additional targets only built on master.

[dagar]

Can we use this to enable it? We should try to avoid having any scattered CONFIG specific logic.

https://github.com/PX4/Firmware/blob/e80d3940a6e5c1d041230afdfca31f06b444d993/boards/px4/sitl/test.cmake#L7

https://github.com/PX4/Firmware/blob/e80d3940a6e5c1d041230afdfca31f06b444d993/cmake/px4_add_board.cmake#L154

[dagar]

This was not caught by CI running on the PR because there are additional targets only built on master.

We could add code coverage back to PR builds for testing feedback.

[MaEtUgR]

Can we use this to enable it? We should try to avoid having any scattered CONFIG specific logic.

I agree, the problem is the order:

• CMAKE_TESTING which can be enabled from the outside also for SITL_default needs to be enabled
• such that CTest gets included and BUILD_TESTING is defined
• then the SITL tests, gtest and px4_add_gtest get included

So I probably need to reorder everything and then it should be possible. The only thing that held me back so far is that I wanted to be able to enable testing also with the sitl_default config because it's just a pain to recompile everything the exact same way if you switch the branch once for simulation once for testing. I try to make things more efficient because knowing I've spend ~15% of the time just waiting for recompilation of already existing binaries in a different build folder or getting GPS to lock in simulation is kind of upsetting.

We could add code coverage back to PR builds for testing feedback.

I think it will be useful while adding tests.

[LorenzMeier]

@MaEtUgR How do we look like here?

[MaEtUgR]

@LorenzMeier It's just a hotfix that would get coverage CI going again. I didn't find a good solution for the cmake flags to enable tests. We discussed the possibility to always include all testing in posix which I don't like that much. Maybe I can have a discussion with @julianoes since he lately looked into testing and might have good ideas.