From: Tomi Ollila <tomi.ollila@iki.fi>
To: Dmitry Kurochkin <dmitry.kurochkin@gmail.com>, notmuch@notmuchmail.org
Subject: Re: [PATCH 4/9] test: add support for external executable
 dependencies
In-Reply-To: <1321494986-18998-5-git-send-email-dmitry.kurochkin@gmail.com>
References: <1321494986-18998-1-git-send-email-dmitry.kurochkin@gmail.com>
	<1321494986-18998-5-git-send-email-dmitry.kurochkin@gmail.com>
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Date: Mon, 28 Nov 2011 23:16:27 +0200
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On Thu, 17 Nov 2011 05:56:21 +0400, Dmitry Kurochkin <dmitry.kurochkin@gmail.com> wrote:
> There is existing support for general prerequisites in the test suite.
> But it is not very convenient to use: every test case has to keep
> track for it's dependencies and they have to be explicitly listed.
> 
> The patch aims to add better support for a particular type of external
> dependencies: external executables.  The main idea is to replace
> missing external binaries with shell functions that have the same
> name.  These functions always fail and keep track of missing
> dependencies for a subtest.  The result reporting functions later can
> check that an external binaries are missing and correctly report SKIP
> result instead of FAIL.  The primary benefit is that the test cases do
> not need to declare their dependencies or be changed in any way.
> ---
>  test/test-lib.sh |   49 +++++++++++++++++++++++++++++++++++++++++--------
>  1 files changed, 41 insertions(+), 8 deletions(-)
> 
> diff --git a/test/test-lib.sh b/test/test-lib.sh
> index f21e45e..ab8c6fd 100755
> --- a/test/test-lib.sh
> +++ b/test/test-lib.sh
> @@ -526,40 +526,53 @@ notmuch_json_show_sanitize ()
>  # - Implicitly by specifying the prerequisite tag in the calls to
>  #   test_expect_{success,failure,code}.
>  #
>  # The single parameter is the prerequisite tag (a simple word, in all
>  # capital letters by convention).
>  
>  test_set_prereq () {
>  	satisfied="$satisfied$1 "
>  }
>  satisfied=" "
>  
>  test_have_prereq () {
>  	case $satisfied in
>  	*" $1 "*)
>  		: yes, have it ;;
>  	*)
>  		! : nope ;;
>  	esac
>  }
>  
> +# declare prerequisite for the given external binary
> +test_declare_external_prereq () {
> +	binary="$1"
> +	test "$#" = 2 && name=$2 || name="$binary(1)"
> +
> +        hash $binary 2>/dev/null || eval "
> +$1 () {
> +	echo -n \"\$test_subtest_missing_external_prereqs_\" | grep -e \" $name \" ||
> +	test_subtest_missing_external_prereqs_=\"$test_subtest_missing_external_prereqs_ $name\"
> +	false
> +}"
> +}
> +

Does this work right ? ... the grep -e \" $name \"   -- part requires
spaces on both side of, but next line does not write trailing space...
... and is there leading space (and also the latest
$test_subtest_missing_external_prereqs_ (just before 'false') is evaluated) ?

This could perhaps be written like the above test_set_prereq &
test_save_prereq:
...
        hash $binary 2>/dev/null || eval "
$binary () {
	test_missing_external_prereq_${binary}_=t
	case \$test_subtest_missing_external_prereqs_ in
        	*' $name '*) ;;
                *) test_subtest_missing_external_prereqs_=\"\$test_subtest_missing_external_prereqs_$name \"
        esac
	false
}

and  test_subtest_missing_external_prereqs_=' '  done in test_reset_state_

(I took some code from current git head.... also perhaps instead of 
setting test_missing_external_prereq_${binary}_=t, (bash) associative
arrays could be taken into use -- the eval to read that information
is a bit hairy -- well, at least that part works for sure :D )

Hmm... how about this:

        hash $binary 2>/dev/null || eval "
$binary () {
        if [ -z \"\${test_missing_external_prereq_[$binary]}\" ]
        then
        	test_missing_external_prereq_[$binary]=t
                test_subtest_missing_external_prereqs_=\"\$test_subtest_missing_external_prereqs_ $name\"
        fi
	false
}

and test_subtest_missing_external_prereqs_ cleared in test_reset_state_ like now.

Tomi