Subject: Re: [GSoC][PATCH v3 2/3] t0000: avoid using pipes

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Sun, 17 Mar 2019 17:47:08 +0100

On Sun, Mar 17 2019, Jonathan Chang wrote:

> The exit code of the upstream in a pipe is ignored thus we should avoid
> using it. By writing out the output of the git command to a file, we can
> test the exit codes of both the commands.
>
> Signed-off-by: Jonathan Chang <[email-masked]>
> ---
>  t/t0000-basic.sh | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
> index 53821f5817..47666b013e 100755
> --- a/t/t0000-basic.sh
> +++ b/t/t0000-basic.sh
> @@ -1118,27 +1118,25 @@ P=$(test_oid root)
>
>  test_expect_success 'git commit-tree records the correct tree in a commit' '
>  	commit0=$(echo NO | git commit-tree $P) &&
> -	tree=$(git show --pretty=raw $commit0 |
> -		 sed -n -e "s/^tree //p" -e "/^author /q") &&
> +	git show --pretty=raw $commit0 >actual &&
> +	tree=$(sed -n -e "s/^tree //p" -e "/^author /q" actual) &&
>  	test "z$tree" = "z$P"

This change is an improvement just changing the "git" invocations. But I
wonder as we're reviewing this / churning this if we couldn't also
modernize this style to just:

    git .. >tmp &&
    sed -n -e <tmp >actual &&
    test_must_be_empty actual

>  '
>
>  test_expect_success 'git commit-tree records the correct parent in a commit' '
>  	commit1=$(echo NO | git commit-tree $P -p $commit0) &&
> -	parent=$(git show --pretty=raw $commit1 |
> -		sed -n -e "s/^parent //p" -e "/^author /q") &&
> +	git show --pretty=raw $commit1 >actual &&
> +	parent=$(sed -n -e "s/^parent //p" -e "/^author /q" actual) &&
>  	test "z$commit0" = "z$parent"

ditto.

>  '
>
>  test_expect_success 'git commit-tree omits duplicated parent in a commit' '
>  	commit2=$(echo NO | git commit-tree $P -p $commit0 -p $commit0) &&
> -	parent=$(git show --pretty=raw $commit2 |
> -		sed -n -e "s/^parent //p" -e "/^author /q" |
> -		sort -u) &&
> +	git show --pretty=raw $commit2 >actual &&
> +	parent=$(sed -n -e "s/^parent //p" -e "/^author /q" actual | sort -u) &&
>  	test "z$commit0" = "z$parent" &&
> -	numparent=$(git show --pretty=raw $commit2 |
> -		sed -n -e "s/^parent //p" -e "/^author /q" |
> -		wc -l) &&
> +	git show --pretty=raw $commit2 >actual &&
> +	numparent=$(sed -n -e "s/^parent //p" -e "/^author /q" actual | wc -l) &&
>  	test $numparent = 1

And stuff like this to (skipping the wc -l):

    sed -n -e <tmp >actual &&
    test_line_count = 1 actual

>  '
>
> @@ -1147,7 +1145,8 @@ test_expect_success 'update-index D/F conflict' '
>  	mv path2 path0 &&
>  	mv tmp path2 &&
>  	git update-index --add --replace path2 path0/file2 &&
> -	numpath0=$(git ls-files path0 | wc -l) &&
> +	git ls-files path0 >actual &&
> +	numpath0=$(wc -l <actual) &&
>  	test $numpath0 = 1

ditto.

>  '
>
> @@ -1162,12 +1161,13 @@ test_expect_success 'very long name in the index handled sanely' '
>  	>path4 &&
>  	git update-index --add path4 &&
>  	(
> -		git ls-files -s path4 |
> -		sed -e "s/	.*/	/" |
> +		git ls-files -s path4 >actual &&
> +		sed -e "s/	.*/	/" actual |
>  		tr -d "\012" &&
>  		echo "$a"
>  	) | git update-index --index-info &&
> -	len=$(git ls-files "a*" | wc -c) &&
> +	git ls-files "a*" >actual &&
> +	len=$(wc -c <actual) &&
>  	test $len = 4098

Ditto. Maybe the initial author wanted to avoid writing out 4k lines,
but now that we're doing so anyway...