From: "SZEDER Gábor" <szeder.dev@gmail.com>
To: Matthew DeVore <matvore@google.com>
Cc: git@vger.kernel.org, Jeff King <peff@peff.net>,
Jonathan Tan <jonathantanmy@google.com>,
Junio C Hamano <gitster@pobox.com>,
Jonathan Nieder <jrn@google.com>,
Eric Sunshine <sunshine@sunshineco.com>
Subject: Re: [PATCH v3 1/5] CodingGuidelines: add shell piping guidelines
Date: Thu, 27 Sep 2018 23:18:26 +0200 [thread overview]
Message-ID: <20180927211826.GL27036@localhost> (raw)
In-Reply-To: <CAMfpvhJ-chi7OMRKjjk79r0uqCqW67Vj9J=tT7Kz-XUmw41H5A@mail.gmail.com>
On Tue, Sep 25, 2018 at 02:58:08PM -0700, Matthew DeVore wrote:
> Here is the new commit with updated message (I will wait for a day or
> two before I send a reroll):
>
> Documentation: add shell guidelines
>
> Add the following guideline to Documentation/CodingGuidelines:
>
> &&, ||, and | should appear at the end of lines, not the
> beginning, and the \ line continuation character should be
> omitted
>
> And the following to t/README (since it is specific to writing tests):
>
> pipes and $(git ...) should be avoided when they swallow exit
> codes of Git processes
>
> Signed-off-by: Matthew DeVore <matvore@google.com>
>
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> index 48aa4edfb..3d2cfea9b 100644
> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -118,6 +118,24 @@ For shell scripts specifically (not exhaustive):
> do this
> fi
>
> + - If a command sequence joined with && or || or | spans multiple
> + lines, put each command on a separate line and put && and || and |
> + operators at the end of each line, rather than the start. This
> + means you don't need to use \ to join lines, since the above
> + operators imply the sequence isn't finished.
> +
> + (incorrect)
> + grep blob verify_pack_result \
> + | awk -f print_1.awk \
> + | sort >actual &&
> + ...
> +
> + (correct)
> + grep blob verify_pack_result |
> + awk -f print_1.awk |
> + sort >actual &&
> + ...
> +
> - We prefer "test" over "[ ... ]".
>
> - We do not write the noiseword "function" in front of shell
> @@ -163,7 +181,6 @@ For shell scripts specifically (not exhaustive):
>
> does not have such a problem.
>
> -
> For C programs:
>
> - We use tabs to indent, and interpret tabs as taking up to
> diff --git a/t/README b/t/README
> index 9028b47d9..3e28b72c4 100644
> --- a/t/README
> +++ b/t/README
> @@ -461,6 +461,32 @@ Don't:
> platform commands; just use '! cmd'. We are not in the business
> of verifying that the world given to us sanely works.
>
> + - Use Git upstream in the non-final position in a piped chain, as in:
Note the starting upper case 'U'.
> +
> + git -C repo ls-files |
> + xargs -n 1 basename |
> + grep foo
> +
> + which will discard git's exit code and may mask a crash. In the
> + above example, all exit codes are ignored except grep's.
> +
> + Instead, write the output of that command to a temporary
> + file with ">" or assign it to a variable with "x=$(git ...)" rather
> + than pipe it.
> +
> + - Use command substitution in a way that discards git's exit code.
'U' again.
> + When assigning to a variable, the exit code is not discarded, e.g.:
> +
> + x=$(git cat-file -p $sha) &&
> + ...
> +
> + is OK because a crash in "git cat-file" will cause the "&&" chain
> + to fail, but:
> +
> + test_cmp expect $(git cat-file -p $sha)
> +
> + is not OK and a crash in git could go undetected.
Well, this is not OK indeed, because it doesn't make any sense in the
first place :) 'test_cmp' requires two paths as argumens, but the
output of 'git cat-file -p' is the whole _content_ of the given object.
> - use perl without spelling it as "$PERL_PATH". This is to help our
Note the starting lower case 'u'.
This is because these are the continuation of the "Don't:" some lines
earlier, so your new points should start with a lower case 'u' as
well.
Sidenote: I think we should consider reformatting this whole section
as:
- Don't do this.
- Don't do that.
because it grew so much that when I look at the last points, then that
starting "Don't:" has already scrolled out of my screen.
> friends on Windows where the platform Perl often adds CR before
> the end of line, and they bundle Git with a version of Perl that
>
>
> >
> >
> > These last two points, however, are specific to test scripts,
> > therefore I think they would be better placed in 't/README', where the
> > rest of the test-specific guidelines are.
> >
> > > For C programs:
> > >
> > > --
> > > 2.19.0.444.g18242da7ef-goog
> > >
next prev parent reply other threads:[~2018-09-27 21:18 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-15 0:02 [PATCH v1 0/2] Cleanup tests for test_cmp argument ordering and "|" placement Matthew DeVore
2018-09-15 0:02 ` [PATCH v1 1/2] t/*: fix pipe placement and remove \'s Matthew DeVore
2018-09-17 16:31 ` Jonathan Nieder
2018-09-17 21:47 ` Matthew DeVore
2018-09-15 0:02 ` [PATCH v1 2/2] t/*: fix ordering of expected/observed arguments Matthew DeVore
2018-09-17 12:56 ` Matthew DeVore
2018-09-15 15:55 ` [PATCH v1 0/2] Cleanup tests for test_cmp argument ordering and "|" placement Junio C Hamano
2018-09-17 22:24 ` [PATCH v2 0/6] Clean up tests for test_cmp arg ordering and pipe placement Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 4/6] tests: Add linter check for pipe placement style Matthew DeVore
2018-09-18 0:34 ` Eric Sunshine
2018-09-19 17:39 ` Matthew DeVore
[not found] ` <cover.1537223021.git.matvore@google.com>
2018-09-17 22:24 ` [PATCH v2 1/6] CodingGuidelines: add shell piping guidelines Matthew DeVore
2018-09-18 0:16 ` Eric Sunshine
2018-09-19 2:11 ` Matthew DeVore
2018-09-19 12:36 ` Eric Sunshine
2018-09-19 14:24 ` Junio C Hamano
2018-09-19 20:06 ` Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 2/6] tests: standardize pipe placement Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 3/6] t/*: fix ordering of expected/observed arguments Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 4/6] tests: add linter check for pipe placement style Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 5/6] tests: split up pipes Matthew DeVore
2018-09-18 1:30 ` Eric Sunshine
2018-09-19 2:33 ` Matthew DeVore
2018-09-17 22:24 ` [PATCH v2 6/6] t9109-git-svn-props.sh: split up several pipes Matthew DeVore
2018-09-18 1:56 ` Eric Sunshine
2018-09-19 2:56 ` Matthew DeVore
2018-09-19 12:50 ` Eric Sunshine
2018-09-19 18:43 ` Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 0/5] Clean up tests for test_cmp arg ordering and pipe placement Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 1/5] CodingGuidelines: add shell piping guidelines Matthew DeVore
2018-09-21 2:06 ` Eric Sunshine
2018-09-21 21:03 ` Matthew DeVore
2018-09-24 21:03 ` SZEDER Gábor
2018-09-25 21:58 ` Matthew DeVore
2018-09-27 21:18 ` SZEDER Gábor [this message]
2018-10-01 23:07 ` Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 2/5] tests: standardize pipe placement Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 3/5] t/*: fix ordering of expected/observed arguments Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 4/5] tests: don't swallow Git errors upstream of pipes Matthew DeVore
2018-09-21 1:43 ` [PATCH v3 5/5] t9109: " Matthew DeVore
2018-10-03 16:25 ` [PATCH v4 0/7] Clean up tests for test_cmp arg ordering and pipe placement Matthew DeVore
2018-10-03 16:25 ` [PATCH v4 1/7] t/README: reformat Do, Don't, Keep in mind lists Matthew DeVore
2018-10-05 6:15 ` Junio C Hamano
2018-10-05 14:57 ` Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 2/7] Documentation: add shell guidelines Matthew DeVore
2018-10-05 16:48 ` Junio C Hamano
2018-10-05 18:21 ` Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 3/7] tests: standardize pipe placement Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 4/7] t/*: fix ordering of expected/observed arguments Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 5/7] tests: don't swallow Git errors upstream of pipes Matthew DeVore
2018-10-05 16:48 ` Junio C Hamano
2018-10-05 17:54 ` Matthew DeVore
2018-10-05 18:12 ` Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 6/7] t9109: " Matthew DeVore
2018-10-03 16:26 ` [PATCH v4 7/7] tests: order arguments to git-rev-list properly Matthew DeVore
2018-10-03 16:33 ` Matthew DeVore
2018-10-05 8:16 ` Junio C Hamano
2018-10-05 21:54 ` [PATCH v5 0/7] subject: Clean up tests for test_cmp arg ordering and pipe placement Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 1/7] t/README: reformat Do, Don't, Keep in mind lists Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 2/7] Documentation: add shell guidelines Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 3/7] tests: standardize pipe placement Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 4/7] t/*: fix ordering of expected/observed arguments Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 5/7] tests: don't swallow Git errors upstream of pipes Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 6/7] t9109: " Matthew DeVore
2018-10-05 21:54 ` [PATCH v5 7/7] tests: order arguments to git-rev-list properly Matthew DeVore
2018-10-06 23:53 ` [PATCH v5 0/7] subject: Clean up tests for test_cmp arg ordering and pipe placement Junio C Hamano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180927211826.GL27036@localhost \
--to=szeder.dev@gmail.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=jonathantanmy@google.com \
--cc=jrn@google.com \
--cc=matvore@google.com \
--cc=peff@peff.net \
--cc=sunshine@sunshineco.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).