Re: [PATCH 08/12] t5520: use test_cmp_rev where possible

[Denton Liu]

Hi Eric,

Thanks for the reviews. I have no idea how you always get to my patches
so quickly but I appreciate the prompt reviews whenever I send a
test-related patchset in.

I've fixed up the other concerns you had and I'll send a v2 later but I
wanted to address this one.

On Thu, Oct 17, 2019 at 07:41:44PM -0400, Eric Sunshine wrote:
> On Thu, Oct 17, 2019 at 7:17 PM Denton Liu <liu.den...@gmail.com> wrote:
> > In case an invocation of `git rev-list` fails within the subshell, the
> > failure will be masked. Remove the subshell and use test_cmp_rev() so
> > that failures can be discovered.
> >
> > Signed-off-by: Denton Liu <liu.den...@gmail.com>
> > ---
> > diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
> > @@ -597,10 +597,10 @@ test_expect_success 'pull --rebase dies early with 
> > dirty working directory' '
> >         test_must_fail git pull &&
> > -       test "$COPY" = "$(git rev-parse --verify me/copy)" &&
> > +       test_cmp_rev "$COPY" me/copy &&
> 
> This transformation doesn't look correct. COPY already holds the
> result of a git-rev-parse invocation:
> 
>     COPY="$(git rev-parse --verify me/copy)" &&
> 
> so passing it to test_cmp_rev() -- which applies its own git-rev-parse
> invocation -- doesn't make sense.

I'll annotate the entire test case with my comments:

        # so we'll be testing that pull --rebase dies early
        test_expect_success 'pull --rebase dies early with dirty working 
directory' '
                git checkout to-rebase &&
                git update-ref refs/remotes/me/copy copy^ &&
                COPY="$(git rev-parse --verify me/copy)" &&
                git rebase --onto $COPY copy &&

                # according to git log --graph, we have this currently:
                #
                # $ git log --pretty=oneline --graph to-rebase copy me/copy
                # * 9366795adb50ef6eb482b610b37cb1fb6edbd3d0 (HEAD -> 
to-rebase) to-rebase
                # * b3dcf50eea47c4ad85faabb0fb74eded71cc829f file3
                # * faf459539411b4557cf735232a3746be073177a9 new file
                # | * f340b1b8932f7b1e016c06867cbdc3f637eeea2d (copy) conflict
                # |/  
                # * 5e86d50a28977ebee5ea378f81591ea558149272 (me/second, 
me/copy, second) modified
                # * d25cf184567afad1dc1e018b2b7d793bc1bd2dc1 original

                test_config branch.to-rebase.remote me &&
                test_config branch.to-rebase.merge refs/heads/copy &&
                test_config branch.to-rebase.rebase true &&

                # we make the tree dirty here
                echo dirty >>file &&
                git add file &&

                # and over here, the pull should fail
                test_must_fail git pull &&

                # but since we're testing that it dies early, we want to
                # make sure that the remote ref doesn't change, which is
                # why it should still be equal
                test_cmp_rev "$COPY" me/copy &&

                git checkout HEAD -- file &&

                # but over here, the pull succeeds...
                git pull &&

                # so as a result, the remote ref should now be updated
                test_cmp_rev ! "$COPY" me/copy
        '

So after grokking the test case, it seems like the the transformation is
indeed correct. Maybe we can replace the last line with

        test_cmp_rev copy me/copy

but I think I'll leave it unless you have any strong opinions.

Thanks,

Denton