Re: [PATCH 0/4] Re: [PATCH 3/4] t: rev-parse-parents: avoid yoda conditions

From: Jeff King <peff@peff.net>
Date: Sep 8, 2013, 05:02 UTC
Message-ID: <20130908050227.GG14019@sigill.intra.peff.net>
In-Reply-To: <CAMP44s1uasvGmCMkMF2N0eTMgOdksG0HqeidXK+159HAi4jkpA@mail.gmail.com>

On Sat, Sep 07, 2013 at 11:52:10PM -0500, Felipe Contreras wrote:

Show 7 quoted lines

> > Ah, you mean "if you think that the compare function should behave like
> > C *_cmp functions, it should be A-B". Perhaps it is simply that I do not
> > think of the function in those terms, but more like "show me the
> > differences from B to A".
> 
> But that is the problem, you are unable to ignore the implementation.
> You don't see test_cmp(), you see 'diff -u'.

Yes, I already said earlier in the thread:

  I certainly think of "test_cmp A B" as "differences from A to B", and
  the order makes sense. IOW, the "test_cmp is diff" abstraction is
  leaky, and that is fine (if it were not leaky, then order would not
  matter at all, but it clearly does).

And I do not think it is a problem. The point of the function is not to abstract away the idea of comparison. The point is to give a hook for people on systems without "diff -u" to run the test suite.

Show 10 quoted lines

> > John mentioned JUnit, NUnit, and PHPUnit earlier in the thread. I
> > believe that Ruby's Test::Unit::Assertions also has
> > assert_equal(expected, actual).
> 
> That's because they all do first expect, then actual.
> 
> assert_equal( expected, actual, failure_message = nil )
> assert_not_equal( expected, actual, failure_message = nil )
> 
> That's why.

I do not see any reason why "not_equal" would not also work as "assert_not_equal(actual, expected)". Maybe I am missing your point.

-Peff