Subject: Re: [PATCH] Add test cases for git-am

From: Junio C Hamano <[email-masked]>
Date: Fri, 30 May 2008 15:12:41 -0700

Stephan Beyer <[email-masked]> writes:

> the reason I added this test is because I'm working on git-sequencer (for
> GSoC'08), which functions as a common backend for git-am, git-rebase, ...
> And I think this test will make my life easier ;-)

Absolutely.  Starting by writing a verifiable specification of what you
will be building (aka "tests") is a very good way.

> As this is my first test, I hope to get some constructive feedback.

    Date: Fri, 30 May 2008 16:04:47 +0200
    From: Stephan Beyer <[email-masked]>
    To: [email-masked]
    Cc: [email-masked]
    Subject: [PATCH] Add test cases for git-am
    Message-ID: <[email-masked]>
    Mail-Followup-To: [email-masked], [email-masked]

Please don't do this "Mail-Followup-To:"; it is rude to others, and it is
rude to me.

 * It is rude to others.  When they want to give feedback to _you_
   privately and say "Reply", it will put me (and the list) on "To:"
   header.  They have to be careful and edit their "To:" header.  You
   stole time from them, which otherwise would have been spent on much
   better things, such as actually giving constructive feedbacks.

 * It is rude to me (or whoever you place on your M-F-T).  I filter and
   sort my incoming mails to give precedence to ones that have me on "To:"
   over the ones that have me on "Cc:".  When people want to give feedback
   to _you_ publicly and say "Reply All", it will again put me (and
   perhaps the list) on "To:" header, and I may not be interested in
   suggestions they are giving to _you_.  You stole time from me, which
   otherwise would have been spent on something better, like sitting back
   and sipping my Caipirinha ;-).

> Perhaps it is also useful to swap t4150 and t4151 or to merge them.

Pehaps.  A single test t4150-am.sh might be enough.

> diff --git a/t/t4151-am.sh b/t/t4151-am.sh
> new file mode 100755
> index 0000000..df4fb5a
> --- /dev/null
> +++ b/t/t4151-am.sh
> @@ -0,0 +1,223 @@
> +#!/bin/sh
> +
> +test_description='git am running'
> +
> +. ./test-lib.sh
> +
> +cat >msg <<EOF
> +second
> +
> +Lorem ipsum dolor sit amet, consectetuer sadipscing elitr, sed diam nonumy
> +...
> +feugait nulla facilisi.
> +EOF
> ...
> +test_expect_success setup '
> +	echo hello >file &&
> +	git add file &&
> +	test_tick &&
> +	git commit -m first &&
> +	git tag first &&
> +	echo world >>file &&
> +	git add file &&
> +	test_tick &&
> +	git commit -s -F msg &&
> +	git tag second &&
> +	git format-patch --stdout first >patch1 &&
> +	tail -n +3 msg >file &&

"tail -n 3" you mean?  Same for "head -n <n>" in other places.

> ...
> +test_expect_success 'am changes committer and keeps author' '
> +	test_tick &&
> +	git checkout first &&
> +	git am patch2 &&
> +	! test -d .dotest &&
> +	test "$(git rev-parse master)" != "$(git rev-parse HEAD)" &&
> +	test "$(git rev-parse master^)" != "$(git rev-parse HEAD^)" &&
> +	test "$(git rev-parse master^^)" = "$(git rev-parse HEAD^^)" &&
> +	test -z "$(git diff master..HEAD)" &&
> +	test -z "$(git diff master^..HEAD^)" &&
> +	compare author master HEAD &&
> +	compare author master^ HEAD^ &&
> +	! compare committer master HEAD &&
> +	! compare committer master^ HEAD^
> +'

Hmmm.  Checking for inequality does not feel so robust.  You will allow
"am" to record garbage and will not be able to detect a breakage.

> +test_expect_success 'am --signoff adds Signed-off-by: line' '
> +	git checkout -b master2 first &&
> +	git am --signoff <patch2 &&
> +	test "$(git cat-file commit HEAD | grep -c "^Signed-off-by:")" -eq 1 &&
> +	test "$(git cat-file commit HEAD^ | grep -c "^Signed-off-by:")" -eq 2
> +'

Again, don't you want to check not just "It added something", but "It
added what we expected it to add"?

> ...
> +test_expect_success 'am --keep really keeps the subject' '
> +	git checkout HEAD^ &&
> +	git am --keep patch4 &&
> +	! test -d .dotest &&
> +	git-cat-file commit HEAD |
> +		grep -q -F "Re: Re: Re: [PATCH 1/5 v2] third"
> +'

... in other words, like this one that checks "It left what we expected it
to in the result".

Other than that, I did not think anything obviously wrong with the patch.