Subject: Re: [PATCH v3 1/3] t5323: test cases for git-pack-redundant

From: SZEDER Gábor <[email-masked]>
Date: Wed, 9 Jan 2019 13:56:28 +0100

On Wed, Jan 02, 2019 at 12:34:54PM +0800, Jiang Xin wrote:
> From: Jiang Xin <[email-masked]>
> 
> Add test cases for git pack-redundant to validate new algorithm for git
> pack-redundant.
> 
> Signed-off-by: Jiang Xin <[email-masked]>
> ---
>  t/t5323-pack-redundant.sh | 84 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100755 t/t5323-pack-redundant.sh
> 
> diff --git a/t/t5323-pack-redundant.sh b/t/t5323-pack-redundant.sh
> new file mode 100755
> index 0000000000..ef6076f065
> --- /dev/null
> +++ b/t/t5323-pack-redundant.sh
> @@ -0,0 +1,84 @@
> +#!/bin/sh
> +#
> +# Copyright (c) 2018 Jiang Xin
> +#
> +
> +test_description='git redundant test'

s/redundant/pack-redundant/ ?

> +
> +. ./test-lib.sh
> +
> +create_commits()
> +{
> +	set -e
> +	parent=
> +	for name in A B C D E F G H I J K L M
> +	do
> +		test_tick
> +		T=$(git write-tree)
> +		if test -z "$parent"
> +		then
> +			sha1=$(echo $name | git commit-tree $T)

There is a considerable effort going on to switch from SHA-1 to a
different hash function, so please don't add any new $sha1 variable;
call it $oid or $commit instead.

> +		else
> +			sha1=$(echo $name | git commit-tree -p $parent $T)
> +		fi
> +		eval $name=$sha1
> +		parent=$sha1
> +	done
> +	git update-ref refs/heads/master $M
> +}
> +
> +create_redundant_packs()
> +{
> +	set -e
> +	cd .git/objects/pack
> +	P1=$(printf "$T\n$A\n" | git pack-objects pack 2>/dev/null)
> +	P2=$(printf "$T\n$A\n$B\n$C\n$D\n$E\n" | git pack-objects pack 2>/dev/null)
> +	P3=$(printf "$C\n$D\n$F\n$G\n$I\n$J\n" | git pack-objects pack 2>/dev/null)
> +	P4=$(printf "$D\n$E\n$G\n$H\n$J\n$K\n" | git pack-objects pack 2>/dev/null)
> +	P5=$(printf "$F\n$G\n$H\n" | git pack-objects pack 2>/dev/null)
> +	P6=$(printf "$F\n$I\n$L\n" | git pack-objects pack 2>/dev/null)
> +	P7=$(printf "$H\n$K\n$M\n" | git pack-objects pack 2>/dev/null)
> +	P8=$(printf "$L\n$M\n" | git pack-objects pack 2>/dev/null)
> +	cd -
> +	eval P$P1=P1:$P1
> +	eval P$P2=P2:$P2
> +	eval P$P3=P3:$P3
> +	eval P$P4=P4:$P4
> +	eval P$P5=P5:$P5
> +	eval P$P6=P6:$P6
> +	eval P$P7=P7:$P7
> +	eval P$P8=P8:$P8
> +}
> +
> +# Create commits and packs
> +create_commits
> +create_redundant_packs

Please perform all setup tasks in a test_expect_success block, so we
get verbose and trace output about what's going on.

Don't use 'set -e', use an &&-chain instead.  To fail the test if a
command in the for loop were to fail you could do something like this:

  for ....
  do
    do-this &&
    do-that ||
    return 1
  done

> +
> +test_expect_success 'clear loose objects' '
> +	git prune-packed &&
> +	test $(find .git/objects -type f | grep -v pack | wc -l) -eq 0

Use something like

  find .git/objects -type f | grep -v pack >out &&
  test_must_be_empty out

instead, so we get an informative error message on failure.

> +'
> +
> +cat >expected <<EOF
> +P1:$P1
> +P4:$P4
> +P5:$P5
> +P6:$P6
> +EOF
> +
> +test_expect_success 'git pack-redundant --all' '
> +	git pack-redundant --all | \

Don't run a git command (especially the particular command the test
script focuses on) upstream of a pipe, because it hides the command's
exit code.  Use an intermediate file instead.

> +		sed -e "s#^.*/pack-\(.*\)\.\(idx\|pack\)#\1#g" | \

This sed command doesn't seem to work on macOS (on Travis CI), and
causes the test to fail with:

  ++git pack-redundant --all
  ++sed -e 's#^.*/pack-\(.*\)\.\(idx\|pack\)#\1#g'
  ++sort -u
  ++read p
  ++sort
  ++eval echo '${P.git/objects/pack/pack-0cf5cb6afaa1bae36b8e61ca398dbe29a15bc74e.idx}'
  ./test-lib.sh: line 697: ${P.git/objects/pack/pack-0cf5cb6afaa1bae36b8e61ca398dbe29a15bc74e.idx}: bad substitution
  ++test_cmp expected actual
  ++diff -u expected actual
  --- expected    2019-01-09 01:53:45.000000000 +0000
  +++ actual      2019-01-09 01:53:45.000000000 +0000
  @@ -1,4 +0,0 @@
  -P1:24ee080366509364d04a138cd4e168dc4ff33354
  -P4:139d8b0cfe7e8970a8f3533835f90278d88de474
  -P5:23e0f02d822fa4bfe5ee63337ba5632cd7be208e
  -P6:deeb289f1749972f1cd57c3b9f359ece2361f60a
  error: last command exited with $?=1
  not ok 2 - git pack-redundant --all

I'm not sure what's wrong with it, though.

Minor nit: 'git pack-redundant' prints one filename per line, so the
'g' at the end of the 's###g' is not necessary.

> +		sort -u | \
> +		while read p; do eval echo "\${P$p}"; done | \
> +		sort > actual && \

Style nit: no space between redirection operator and filename

> +	test_cmp expected actual
> +'
> +
> +test_expect_success 'remove redundant packs' '
> +	git pack-redundant --all | xargs rm &&
> +	git fsck &&
> +	test $(git pack-redundant --all | wc -l) -eq 0
> +'
> +
> +test_done
> -- 
> 2.14.5.agit.2
>