Add coverage to tests

[matheusgomes28]

Add coverage reporting to unit tests. Difficult task!

TODOS 📑

• Compile with --coverage in gcc. 📔
• Integrate gcov and lcov to read the profiling data. 👓
• Deploy coverage HTML to artifacts. 📫

[matheusgomes28]

Alternatively to gcov and lcov, you can integrate with codecov.

The plan is:

• Build debug with coverage flags, --coverage suffices.
• Calling lcov after the tests run: lcov --capture --directory . --output-file coverage.info from project dir suffices.
• Remove the stl and conan files with lcov --remove coverage.info '/usr/*' --output-file coverage.info

Uploading the coverage info:

• Create pipeline secret with Codecov PAT
• Upload the coverage info with bash <(curl -s https://codecov.io/bash) -f coverage.info || echo "Codecov did not collect coverage reports"

[matheusgomes28]

Perhaps the following would be necessary if there are issues with lcov finding the source files:

lcov -d BUILD/app/packages/ --capture --no-external --output-file app.info
     --rc geninfo_adjust_src_path="${PROJECT_ROOT}/build/unix-deb
     => ${PROJECT_ROOT}"

[matheusgomes28]

Turns out the docker container does not have lcov. Make sure we add this in, research a good lcov version to add.

[matheusgomes28]

Long but closed with #61