Re: [PATCH] tests: Introduce test_seq

[Jeff King <peff@peff.net>]

On Fri, Aug 03, 2012 at 09:57:15PM +0200, Michał Kiedrowicz wrote:

> Jeff King wrote:
> 
> 	The seq command is GNU-ism, and is missing at least in older BSD
> 	releases and their derivatives, not to mention antique
> 	commercial Unixes.
> 
> 	We already purged it in b3431bc (Don't use seq in tests, not
> 	everyone has it, 2007-05-02), but a few new instances have crept
> 	in. They went unnoticed because they are in scripts that are not
> 	run by default.
> 
> This commit replaces them with test_seq that is implemented with a Perl
> snippet (proposed by Jeff).  This is better than inlining this snippet
> everywhere it's needed because it's easier to read and it's easier to
> change the implementation (e.g. to C) if we ever decide to remove Perl
> from the test suite.
> 
> Note that test_seq is not a complete replacement for seq(1).  It just
> has what we need now.
> 
> There are also many places that do `for i in 1 2 3 ...` but I'm not sure
> if it's worth converting them to test_seq.  That would introduce running
> more processes of Perl during the tests and might increase the total
> time tests take.
> 
> Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>

Fine explanation, but...

> diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
> index 5580c22..a1361e5 100644
> --- a/t/perf/perf-lib.sh
> +++ b/t/perf/perf-lib.sh
> @@ -163,7 +163,7 @@ test_perf () {
>  		else
>  			echo "perf $test_count - $1:"
>  		fi
> -		for i in $(seq 1 $GIT_PERF_REPEAT_COUNT); do
> +		for i in $(test_seq 1 $GIT_PERF_REPEAT_COUNT); do

Two args to test_seq, but...

> +# test_seq is a portable replacement for seq(1).
> +# It may be used like:
> +#
> +#	for i in `test_seq 100`; do
> +#		echo $i
> +#	done
> +
> +test_seq () {
> +	test $# = 1 ||
> +	error "bug in the test script: not 1 parameter to test_seq"
> +	last=$1
> +	"$PERL_PATH" -le "print for 1..$last"
> +}

it wants only one.

I think you would want:

  test $# = 1 && set -- 1 "$@"
  "$PERL_PATH" -le "print for $1..$2"

It might also be worth quoting the parameters like this:

  "$PERL_PATH" -le "print for '$1'..'$2'"

so that "test_seq a f" works, too.

-Peff