Ideally, we would like to get 100% code coverage of stErlang with tests. But since stErlang is specialised to some restrictions it makes it a bit non-trivial.
Fortunately, there is only a handful of such specialisations, and we can document them and disable coverage checking for corresponding small portions of stErlang code.
There are also states which stErlang should not get into (by design).
The corresponding portions of code explicitly throw IllegalStateException and
are also excluded from code coverage reports.
The mechanism for excluding code from coverage is
$COVERAGE-OFF$/$COVERAGE-ON$ comments.
Printing feedback (errors and warnings) to console is not tested in integration
tests. Those places are commented with $COVERAGE-OFF$ interactivity.
It is possible, however, to test it - since System.out can be mocked.