Re: [PATCH] diff: exit(1) if 'diff --quiet <repo file> <external file>' finds changes

[Tim Henigan <tim.henigan@gmail.com>]

On Fri, Jun 15, 2012 at 4:10 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Tim Henigan <tim.henigan@gmail.com> writes:
>
>> I will send v2 with the change to 'diff-no-index.c' suggested by
>> Junio.  I will also include the 'test_expect_code' improvement
>> suggested by Jeff.
>
> Also the test script shouldn't be just testing a simplest case, I
> would think.
>
> For example, comparing two files with "a b c" and "a  b c" in them
> with "--quiet" should yield "They are different!" while running the
> same comparison with "--quiet -w" should say "They are the same!",
> no?

To obtain full coverage, it seems we need to test:
    1) git diff --quiet <file in repo> <file outside repo>
    2) git diff --quiet <file outside repo> <file outside repo>

for each of the following options:
    a) no additional options
    b) --ignore-space-at-eol
    c) --ignore-all-space

These seem like the only diff options that should be tested...am I
missing anything?

Because some of the tests require one directory that is a repo and one
directory that is not, it seems best to create a new test file with
$TEST_NO_CREATE_REPO set.  Then the setup function can create both the
repo and the plain directory.

So, I am thinking of adding 't/t4054-diff-outside-repo.sh' that does
the following:

  1) setup (includes a cd into the repo directory)
  2) git diff --quiet, one outside repo, matching files
  3) git diff --quiet, one outside repo, different files
  4) git diff --quiet, one outside repo, ignore trailing whitespace
  5) git diff --quiet, one outside repo, ignore all whitespace
  6) git diff --quiet, both outside repo, matching files
  7) git diff --quiet, both outside repo, different files
  8) git diff --quiet, both outside repo, ignore trailing whitespace
  9) git diff --quiet, both outside repo, ignore all whitespace
  10) cleanup (cd back to $HOME test directory)

Does this sound reasonable?