[RFC PATCH 1/2] selftests: Start shell API

[chrubis at suse.cz (Cyril Hrubis)]

Hi!
> +ksft_pass()
> +{
> +	echo "[PASS] $TEST: $1"
> +	exit $KSFT_PASS
> +}
> +
> +ksft_fail()
> +{
> +	echo "[FAIL] $TEST: $1"
> +	exit $KSFT_FAIL
> +}

I think that the main disadvantage here is that these functions call
exit instead of storing the results which leads to a common pattern of
passing the result up the function call chain which is prone to errors.

What I have learned the hard way over the years is that the result
reporting should be separated from the functions that exit the tests and
that the test code should not be trusted with passing the overall test
result at the end. I've seen too many cases where the actuall failure
was ignored becaues the failure was lost on it's way to the main
function.

Another lesson is that tests shouldn't implement the main() function,
that is something that the test library should do, which allows for
resources to be listed in a declarative way instead of calling init
funcitons at the start of the tests. Which means that in LTP you can say
"mount at least 512MB device formatted with ext4 to this mount point"
and all this handled in the test library before the actual test starts.

As the last point this completely misses a cleanup callback support,
i.e. function that is called to clean up if you need to exit in the
middle of a test in a case of an error.

-- 
Cyril Hrubis
chrubis at suse.cz