[2/2] t2200: modify code syntax

Commit Message

Amanda Shafack Oct. 17, 2020, 4:02 p.m. UTC

From: Amanda  Shafack <[e-mail]>

Using the logical not operator on both the git and grep command is
redundant, since the main check is done at the level of the grep
command.

Apply the logical not operator only to the grep command.

Co-authored-by: Johannes Schindelin <[e-mail]>
Signed-off-by: Amanda Shafack <[e-mail]>
---
 t/t2200-add-update.sh | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Eric Sunshine Oct. 18, 2020, 5:55 a.m. UTC | #1

On Sat, Oct 17, 2020 at 12:02 PM Amanda Shafack via GitGitGadget
<[e-mail]> wrote:
> Using the logical not operator on both the git and grep command is
> redundant, since the main check is done at the level of the grep
> command.
>
> Apply the logical not operator only to the grep command.
> ---
> diff --git a/t/t2200-add-update.sh b/t/t2200-add-update.sh
> @@ -179,10 +179,8 @@ test_expect_success 'add -u resolves unmerged paths' '
> -       ! (
> -               git ls-files >actual &&
> -               grep "non-existent" actual
> -       )
> +       git ls-files >actual &&
> +       ! grep "non-existent" actual

The commit message talks only about redundancy of applying the logical
NOT operator to the combined subshell content, but what it misses is
that transformation of:

    ! (git ls-files | grep "non-existent")

in patch [1/2] into:

    ! (
        git ls-files >actual &&
        grep "non-existent" actual
    )

is actively wrong. In particular, if `git ls-files` itself fails, then
the `grep` will never get run, and the subshell will exit with a
failure, however, the NOT then turns that failure into a success,
which is quite undesirable. The test should fail if either `git
ls-files` fails or if the `grep` expectation is not met; it should not
succeed when `git ls-files` fails.

So, the correct thing to do is to merge [1/2] and [2/2] into a single
patch which directly transforms:

    ! (git ls-files | grep "non-existent")

into:

    git ls-files >actual &&
    ! grep "non-existent" actual

Amanda Shafack Oct. 18, 2020, 1:59 p.m. UTC | #2

I agree with you. I have made these changes as well.
Thanks


On Sun, Oct 18, 2020 at 6:56 AM Eric Sunshine <[e-mail]> wrote:
>
> On Sat, Oct 17, 2020 at 12:02 PM Amanda Shafack via GitGitGadget
> <[e-mail]> wrote:
> > Using the logical not operator on both the git and grep command is
> > redundant, since the main check is done at the level of the grep
> > command.
> >
> > Apply the logical not operator only to the grep command.
> > ---
> > diff --git a/t/t2200-add-update.sh b/t/t2200-add-update.sh
> > @@ -179,10 +179,8 @@ test_expect_success 'add -u resolves unmerged paths' '
> > -       ! (
> > -               git ls-files >actual &&
> > -               grep "non-existent" actual
> > -       )
> > +       git ls-files >actual &&
> > +       ! grep "non-existent" actual
>
> The commit message talks only about redundancy of applying the logical
> NOT operator to the combined subshell content, but what it misses is
> that transformation of:
>
>     ! (git ls-files | grep "non-existent")
>
> in patch [1/2] into:
>
>     ! (
>         git ls-files >actual &&
>         grep "non-existent" actual
>     )
>
> is actively wrong. In particular, if `git ls-files` itself fails, then
> the `grep` will never get run, and the subshell will exit with a
> failure, however, the NOT then turns that failure into a success,
> which is quite undesirable. The test should fail if either `git
> ls-files` fails or if the `grep` expectation is not met; it should not
> succeed when `git ls-files` fails.
>
> So, the correct thing to do is to merge [1/2] and [2/2] into a single
> patch which directly transforms:
>
>     ! (git ls-files | grep "non-existent")
>
> into:
>
>     git ls-files >actual &&
>     ! grep "non-existent" actual

Patch

diff --git a/t/t2200-add-update.sh b/t/t2200-add-update.sh
index 2d850bb372..7cb7a70382 100755
--- a/t/t2200-add-update.sh
+++ b/t/t2200-add-update.sh
@@ -179,10 +179,8 @@  test_expect_success 'add -u resolves unmerged paths' '
 
 test_expect_success '"add -u non-existent" should fail' '
 	test_must_fail git add -u non-existent &&
-	! (
-		git ls-files >actual &&
-		grep "non-existent" actual
-	)
+	git ls-files >actual &&
+	! grep "non-existent" actual
 '
 
 test_done