From: Dmitry Kurochkin <dmitry.kurochkin@gmail.com>
To: Jameson Graef Rollins <jrollins@finestructure.net>,
	Tomi Ollila <tomi.ollila@iki.fi>, notmuch@notmuchmail.org
Subject: Re: [PATCH] test: make test_expect_equal_file() arguments flexible
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References: <1328080794-24670-1-git-send-email-dmitry.kurochkin@gmail.com>
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Date: Thu, 02 Feb 2012 03:42:29 +0400
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Hi Jameson.

On Wed, 01 Feb 2012 09:24:32 -0800, Jameson Graef Rollins <jrollins@finestructure.net> wrote:
> On Wed, 01 Feb 2012 14:37:53 +0400, Dmitry Kurochkin <dmitry.kurochkin@gmail.com> wrote:
> > On Wed, 01 Feb 2012 12:18:08 +0200, Tomi Ollila <tomi.ollila@iki.fi> wrote:
> > > 
> > > There are at least these options here
> > > 
> > > 1) go through all ~100 places where test_expect_equal_file is used
> > >    and fix the call order: quick look tells that the offending uses
> > >    are in dump-restore, hooks, search-limiting and symbol-hiding.
> > > 
> > > 2) enforce "expected" filename has some format *and* fix all current
> > >    uses of it. Add testbed_error () function which yells loudly ane exits...
> > > 
> > > 3) guess which is output and which is expected from args so that 
> > >    machine helps tester here (for both diff output & copied files)a
> > > 
> > > 4) just copy compared files to some directory, those are named as
> > >    basename of the original -- diff order still inconsistent.
> > > 
> > > 
> > > I'd just go with option 1 and fix new *violations* when stumble upon one.
> > > 
> > 
> > Option 1 does not solve the problem.  New violations would apper and
> > need to be fixed again.  I am for option 2.
> 
> How is enforcing use of a particular filename better and more robust
> than enforcing argument order?

Filename check is a way to make sure the argument order is correct.

>  You'll still have to force an arbitrary
> heuristic.  And you'll still be vulnerable to people messing up the file
> names (which actually seems easier to get wrong than messing up the
> order).

Do you mean that people would start writing tests with filenames like:

  test_expect_equal_file EXPECTED1 EXPECTED2

?  That is possible, of course.  But do you seriously believe that
deliberately changing file names in a way that violates common sense and
is inconsistent with all other code is "easier" than writing "EXPECTED
OUTPUT" in the wrong order?  I do not think so.  And it would definately
be easier to catch during review.

>  And you'll have to have more code to parse the argument
> strings.

That is one case statement, with one non-empty case, with one error
call.

>  And you'll still get inconsistent diffs.
> 

No, you do not.  That is the point.

> If this is really a problem, I vote for 1.  In general, I am not in
> favor of making the test suite more complicated than it needs to be.
> 

Ok.  I plan to send a patch soon.  If my arguments do not convince
enough people, I will move along.

Regards,
  Dmitry

> jamie.