From: Dmitry Kurochkin <dmitry.kurochkin@gmail.com>
To: Tomi Ollila <tomi.ollila@iki.fi>, notmuch@notmuchmail.org
Subject: Re: [PATCH 4/9] test: add support for external executable
 dependencies
In-Reply-To: <87d3cbx6aa.fsf@gmail.com>
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	<yf662i4j6c4.fsf@taco2.nixu.fi> <87d3cbx6aa.fsf@gmail.com>
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Date: Tue, 29 Nov 2011 02:13:53 +0400
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On Tue, 29 Nov 2011 01:53:49 +0400, Dmitry Kurochkin <dmitry.kurochkin@gmail.com> wrote:
> On Mon, 28 Nov 2011 23:16:27 +0200, Tomi Ollila <tomi.ollila@iki.fi> wrote:
> > 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 ?
> 
> It does not.
> 
> Moreover, there is a missing backslash before
> $test_subtest_missing_external_prereqs_ (and that is why I did not
> notice the bug during my poor testing).
> 
> > ... 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_
> > 
> 
> Well, this approach would obviously be better, at least because it does
> work.  But IMO it is too complex, and essentially has the same problem
> as the current code: it mixes the check with diagnostic message.
> 
> We already have a proper way to check if dependency is missing already:
> test_missing_external_prereq_${binary}_.  We should check it and add the
> binary to test_subtest_missing_external_prereqs_ if it is not set.  And
> move setting of test_missing_external_prereq_${binary}_ below.
> 
> > (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 )
> > 
> 
> Yes!  I like using hash here.
> 
> > 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
> > }
> > 
> 
> There is some inconsistent indenting in the above code (mixed tabs and
> spaces).  Also test_require_external_prereq() should be changed as well.
> 
> Otherwise I like it.  Would you please submit a patch?
> 

Actually, test_missing_external_prereq_${binary}_ must be set outside of
the $binary() function.  It indicates that the binary is missing, not
that it is required.  I will send some patches to fix these bugs.  Then
you can change it to use hashes.

Regards,
  Dmitry

> Regards,
>   Dmitry
> 
> > and test_subtest_missing_external_prereqs_ cleared in test_reset_state_ like now.
> > 
> > Tomi