git/t/test-lib-functions.sh

# Library of functions shared by all tests scripts, included by
# test-lib.sh.
#
# Copyright (c) 2005 Junio C Hamano
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see http://www.gnu.org/licenses/ .

# The semantics of the editor variables are that of invoking
# sh -c "$EDITOR \"$@\"" files ...
#
# If our trash directory contains shell metacharacters, they will be
# interpreted if we just set $EDITOR directly, so do a little dance with
# environment variables to work around this.
#
# In particular, quoting isn't enough, as the path may contain the same quote
# that we're using.
test_set_editor () {
	FAKE_EDITOR="$1"
	export FAKE_EDITOR
	EDITOR='"$FAKE_EDITOR"'
	export EDITOR
}

test_decode_color () {
	awk '
		function name(n) {
			if (n == 0) return "RESET";
			if (n == 1) return "BOLD";
			if (n == 2) return "FAINT";
			if (n == 3) return "ITALIC";
			if (n == 7) return "REVERSE";
			if (n == 30) return "BLACK";
			if (n == 31) return "RED";
			if (n == 32) return "GREEN";
			if (n == 33) return "YELLOW";
			if (n == 34) return "BLUE";
			if (n == 35) return "MAGENTA";
			if (n == 36) return "CYAN";
			if (n == 37) return "WHITE";
			if (n == 40) return "BLACK";
			if (n == 41) return "BRED";
			if (n == 42) return "BGREEN";
			if (n == 43) return "BYELLOW";
			if (n == 44) return "BBLUE";
			if (n == 45) return "BMAGENTA";
			if (n == 46) return "BCYAN";
			if (n == 47) return "BWHITE";
		}
		{
			while (match($0, /\033\[[0-9;]*m/) != 0) {
				printf "%s<", substr($0, 1, RSTART-1);
				codes = substr($0, RSTART+2, RLENGTH-3);
				if (length(codes) == 0)
					printf "%s", name(0)
				else {
					n = split(codes, ary, ";");
					sep = "";
					for (i = 1; i <= n; i++) {
						printf "%s%s", sep, name(ary[i]);
						sep = ";"
					}
				}
				printf ">";
				$0 = substr($0, RSTART + RLENGTH, length($0) - RSTART - RLENGTH + 1);
			}
			print
		}
	'
}

lf_to_nul () {
	perl -pe 'y/\012/\000/'
}

nul_to_q () {
	perl -pe 'y/\000/Q/'
}

q_to_nul () {
	perl -pe 'y/Q/\000/'
}

q_to_cr () {
	tr Q '\015'
}

q_to_tab () {
	tr Q '\011'
}

qz_to_tab_space () {
	tr QZ '\011\040'
}

append_cr () {
	sed -e 's/$/Q/' | tr Q '\015'
}

remove_cr () {
	tr '\015' Q | sed -e 's/Q$//'
}

# In some bourne shell implementations, the "unset" builtin returns
# nonzero status when a variable to be unset was not set in the first
# place.
#
# Use sane_unset when that should not be considered an error.

sane_unset () {
	unset "$@"
	return 0
}

test_tick () {
	if test -z "${test_tick+set}"
	then
		test_tick=1112911993
	else
		test_tick=$(($test_tick + 60))
	fi
	GIT_COMMITTER_DATE="$test_tick -0700"
	GIT_AUTHOR_DATE="$test_tick -0700"
	export GIT_COMMITTER_DATE GIT_AUTHOR_DATE
}

# Stop execution and start a shell. This is useful for debugging tests.
#
# Be sure to remove all invocations of this command before submitting.
# WARNING: the shell invoked by this helper does not have the same environment
# as the one running the tests (shell variables and functions are not
# available, and the options below further modify the environment). As such,
# commands copied from a test script might behave differently than when
# running the test.
#
# Usage: test_pause [options]
#   -t
#	Use your original TERM instead of test-lib.sh's "dumb".
#	This usually restores color output in the invoked shell.
#   -s
#	Invoke $SHELL instead of $TEST_SHELL_PATH.
#   -h
#	Use your original HOME instead of test-lib.sh's "$TRASH_DIRECTORY".
#	This allows you to use your regular shell environment and Git aliases.
#	CAUTION: running commands copied from a test script into the paused shell
#	might result in files in your HOME being overwritten.
#   -a
#	Shortcut for -t -s -h

test_pause () {
	PAUSE_TERM=$TERM &&
	PAUSE_SHELL=$TEST_SHELL_PATH &&
	PAUSE_HOME=$HOME &&
	while test $# != 0
	do
		case "$1" in
		-t)
			PAUSE_TERM="$USER_TERM"
			;;
		-s)
			PAUSE_SHELL="$SHELL"
			;;
		-h)
			PAUSE_HOME="$USER_HOME"
			;;
		-a)
			PAUSE_TERM="$USER_TERM"
			PAUSE_SHELL="$SHELL"
			PAUSE_HOME="$USER_HOME"
			;;
		*)
			break
			;;
		esac
		shift
	done &&
	TERM="$PAUSE_TERM" HOME="$PAUSE_HOME" "$PAUSE_SHELL" <&6 >&5 2>&7
}

# Wrap git with a debugger. Adding this to a command can make it easier
# to understand what is going on in a failing test.
#
# Usage: debug [options] <git command>
#   -d <debugger>
#   --debugger=<debugger>
#	Use <debugger> instead of GDB
#   -t
#	Use your original TERM instead of test-lib.sh's "dumb".
#	This usually restores color output in the debugger.
#	WARNING: the command being debugged might behave differently than when
#	running the test.
#
# Examples:
#     debug git checkout master
#     debug --debugger=nemiver git $ARGS
#     debug -d "valgrind --tool=memcheck --track-origins=yes" git $ARGS
debug () {
	GIT_DEBUGGER=1 &&
	DEBUG_TERM=$TERM &&
	while test $# != 0
	do
		case "$1" in
		-t)
			DEBUG_TERM="$USER_TERM"
			;;
		-d)
			GIT_DEBUGGER="$2" &&
			shift
			;;
		--debugger=*)
			GIT_DEBUGGER="${1#*=}"
			;;
		*)
			break
			;;
		esac
		shift
	done &&

	dotfiles=".gdbinit .lldbinit"

	for dotfile in $dotfiles
	do
		dotfile="$USER_HOME/$dotfile" &&
		test -f "$dotfile" && cp "$dotfile" "$HOME" || :
	done &&

	TERM="$DEBUG_TERM" GIT_DEBUGGER="${GIT_DEBUGGER}" "$@" <&6 >&5 2>&7 &&

	for dotfile in $dotfiles
	do
		rm -f "$HOME/$dotfile"
	done
}

# Usage: test_commit [options] <message> [<file> [<contents> [<tag>]]]
#   -C <dir>:
#	Run all git commands in directory <dir>
#   --notick
#	Do not call test_tick before making a commit
#   --append
#	Use ">>" instead of ">" when writing "<contents>" to "<file>"
#   --printf
#       Use "printf" instead of "echo" when writing "<contents>" to
#       "<file>", use this to write escape sequences such as "\0", a
#       trailing "\n" won't be added automatically. This option
#       supports nothing but the FORMAT of printf(1), i.e. no custom
#       ARGUMENT(s).
#   --signoff
#	Invoke "git commit" with --signoff
#   --author <author>
#	Invoke "git commit" with --author <author>
#   --no-tag
#	Do not tag the resulting commit
#   --annotate
#	Create an annotated tag with "--annotate -m <message>". Calls
#	test_tick between making the commit and tag, unless --notick
#	is given.
#
# This will commit a file with the given contents and the given commit
# message, and tag the resulting commit with the given tag name.
#
# <file>, <contents>, and <tag> all default to <message>.

test_commit () {
	notick= &&
	echo=echo &&
	append= &&
	author= &&
	signoff= &&
	indir= &&
	tag=light &&
	while test $# != 0
	do
		case "$1" in
		--notick)
			notick=yes
			;;
		--printf)
			echo=printf
			;;
		--append)
			append=yes
			;;
		--author)
			author="$2"
			shift
			;;
		--signoff)
			signoff="$1"
			;;
		--date)
			notick=yes
			GIT_COMMITTER_DATE="$2"
			GIT_AUTHOR_DATE="$2"
			shift
			;;
		-C)
			indir="$2"
			shift
			;;
		--no-tag)
			tag=none
			;;
		--annotate)
			tag=annotate
			;;
		*)
			break
			;;
		esac
		shift
	done &&
	indir=${indir:+"$indir"/} &&
	file=${2:-"$1.t"} &&
	if test -n "$append"
	then
		$echo "${3-$1}" >>"$indir$file"
	else
		$echo "${3-$1}" >"$indir$file"
	fi &&
	git ${indir:+ -C "$indir"} add -- "$file" &&
	if test -z "$notick"
	then
		test_tick
	fi &&
	git ${indir:+ -C "$indir"} commit \
	    ${author:+ --author "$author"} \
	    $signoff -m "$1" &&
	case "$tag" in
	none)
		;;
	light)
		git ${indir:+ -C "$indir"} tag "${4:-$1}"
		;;
	annotate)
		if test -z "$notick"
		then
			test_tick
		fi &&
		git ${indir:+ -C "$indir"} tag -a -m "$1" "${4:-$1}"
		;;
	esac
}

# Call test_merge with the arguments "<message> <commit>", where <commit>
# can be a tag pointing to the commit-to-merge.

test_merge () {
	label="$1" &&
	shift &&
	test_tick &&
	git merge -m "$label" "$@" &&
	git tag "$label"
}

# Efficiently create <nr> commits, each with a unique number (from 1 to <nr>
# by default) in the commit message.
#
# Usage: test_commit_bulk [options] <nr>
#   -C <dir>:
#	Run all git commands in directory <dir>
#   --ref=<n>:
#	ref on which to create commits (default: HEAD)
#   --start=<n>:
#	number commit messages from <n> (default: 1)
#   --message=<msg>:
#	use <msg> as the commit mesasge (default: "commit %s")
#   --filename=<fn>:
#	modify <fn> in each commit (default: %s.t)
#   --contents=<string>:
#	place <string> in each file (default: "content %s")
#   --id=<string>:
#	shorthand to use <string> and %s in message, filename, and contents
#
# The message, filename, and contents strings are evaluated by printf, with the
# first "%s" replaced by the current commit number. So you can do:
#
#   test_commit_bulk --filename=file --contents="modification %s"
#
# to have every commit touch the same file, but with unique content.
#
test_commit_bulk () {
	tmpfile=.bulk-commit.input
	indir=.
	ref=HEAD
	n=1
	message='commit %s'
	filename='%s.t'
	contents='content %s'
	while test $# -gt 0
	do
		case "$1" in
		-C)
			indir=$2
			shift
			;;
		--ref=*)
			ref=${1#--*=}
			;;
		--start=*)
			n=${1#--*=}
			;;
		--message=*)
			message=${1#--*=}
			;;
		--filename=*)
			filename=${1#--*=}
			;;
		--contents=*)
			contents=${1#--*=}
			;;
		--id=*)
			message="${1#--*=} %s"
			filename="${1#--*=}-%s.t"
			contents="${1#--*=} %s"
			;;
		-*)
			BUG "invalid test_commit_bulk option: $1"
			;;
		*)
			break
			;;
		esac
		shift
	done
	total=$1

	add_from=
	if git -C "$indir" rev-parse --quiet --verify "$ref"
	then
		add_from=t
	fi

	while test "$total" -gt 0
	do
		test_tick &&
		echo "commit $ref"
		printf 'author %s <%s> %s\n' \
			"$GIT_AUTHOR_NAME" \
			"$GIT_AUTHOR_EMAIL" \
			"$GIT_AUTHOR_DATE"
		printf 'committer %s <%s> %s\n' \
			"$GIT_COMMITTER_NAME" \
			"$GIT_COMMITTER_EMAIL" \
			"$GIT_COMMITTER_DATE"
		echo "data <<EOF"
		printf "$message\n" $n
		echo "EOF"
		if test -n "$add_from"
		then
			echo "from $ref^0"
			add_from=
		fi
		printf "M 644 inline $filename\n" $n
		echo "data <<EOF"
		printf "$contents\n" $n
		echo "EOF"
		echo
		n=$((n + 1))
		total=$((total - 1))
	done >"$tmpfile"

	git -C "$indir" \
	    -c fastimport.unpacklimit=0 \
	    fast-import <"$tmpfile" || return 1

	# This will be left in place on failure, which may aid debugging.
	rm -f "$tmpfile"

	# If we updated HEAD, then be nice and update the index and working
	# tree, too.
	if test "$ref" = "HEAD"
	then
		git -C "$indir" checkout -f HEAD || return 1
	fi

}

# This function helps systems where core.filemode=false is set.
# Use it instead of plain 'chmod +x' to set or unset the executable bit
# of a file in the working directory and add it to the index.

test_chmod () {
	chmod "$@" &&
	git update-index --add "--chmod=$@"
}

# Get the modebits from a file or directory, ignoring the setgid bit (g+s).
# This bit is inherited by subdirectories at their creation. So we remove it
# from the returning string to prevent callers from having to worry about the
# state of the bit in the test directory.
#
test_modebits () {
	ls -ld "$1" | sed -e 's|^\(..........\).*|\1|' \
			  -e 's|^\(......\)S|\1-|' -e 's|^\(......\)s|\1x|'
}

# Unset a configuration variable, but don't fail if it doesn't exist.
test_unconfig () {
	config_dir=
	if test "$1" = -C
	then
		shift
		config_dir=$1
		shift
	fi
	git ${config_dir:+-C "$config_dir"} config --unset-all "$@"
	config_status=$?
	case "$config_status" in
	5) # ok, nothing to unset
		config_status=0
		;;
	esac
	return $config_status
}

# Set git config, automatically unsetting it after the test is over.
test_config () {
	config_dir=
	if test "$1" = -C
	then
		shift
		config_dir=$1
		shift
	fi
	test_when_finished "test_unconfig ${config_dir:+-C '$config_dir'} '$1'" &&
	git ${config_dir:+-C "$config_dir"} config "$@"
}

test_config_global () {
	test_when_finished "test_unconfig --global '$1'" &&
	git config --global "$@"
}

write_script () {
	{
		echo "#!${2-"$SHELL_PATH"}" &&
		cat
	} >"$1" &&
	chmod +x "$1"
}

# Usage: test_hook [options] <hook-name> <<-\EOF
#
#   -C <dir>:
#	Run all git commands in directory <dir>
#   --setup
#	Setup a hook for subsequent tests, i.e. don't remove it in a
#	"test_when_finished"
#   --clobber
#	Overwrite an existing <hook-name>, if it exists. Implies
#	--setup (i.e. the "test_when_finished" is assumed to have been
#	set up already).
#    --disable
#	Disable (chmod -x) an existing <hook-name>, which must exist.
#    --remove
#	Remove (rm -f) an existing <hook-name>, which must exist.
test_hook () {
	setup= &&
	clobber= &&
	disable= &&
	remove= &&
	indir= &&
	while test $# != 0
	do
		case "$1" in
		-C)
			indir="$2" &&
			shift
			;;
		--setup)
			setup=t
			;;
		--clobber)
			clobber=t
			;;
		--disable)
			disable=t
			;;
		--remove)
			remove=t
			;;
		-*)
			BUG "invalid argument: $1"
			;;
		*)
			break
			;;
		esac &&
		shift
	done &&

	git_dir=$(git -C "$indir" rev-parse --absolute-git-dir) &&
	hook_dir="$git_dir/hooks" &&
	hook_file="$hook_dir/$1" &&
	if test -n "$disable$remove"
	then
		test_path_is_file "$hook_file" &&
		if test -n "$disable"
		then
			chmod -x "$hook_file"
		elif test -n "$remove"
		then
			rm -f "$hook_file"
		fi &&
		return 0
	fi &&
	if test -z "$clobber"
	then
		test_path_is_missing "$hook_file"
	fi &&
	if test -z "$setup$clobber"
	then
		test_when_finished "rm \"$hook_file\""
	fi &&
	write_script "$hook_file"
}

# Use test_set_prereq to tell that a particular prerequisite is available.
# The prerequisite can later be checked for in two ways:
#
# - Explicitly using test_have_prereq.
#
# - Implicitly by specifying the prerequisite tag in the calls to
#   test_expect_{success,failure}
#
# The single parameter is the prerequisite tag (a simple word, in all
# capital letters by convention).

test_unset_prereq () {
	! test_have_prereq "$1" ||
	satisfied_prereq="${satisfied_prereq% $1 *} ${satisfied_prereq#* $1 }"
}

test_set_prereq () {
	if test -n "$GIT_TEST_FAIL_PREREQS_INTERNAL"
	then
		case "$1" in
		# The "!" case is handled below with
		# test_unset_prereq()
		!*)
			;;
		# List of things we can't easily pretend to not support
		SYMLINKS)
			;;
		# Inspecting whether GIT_TEST_FAIL_PREREQS is on
		# should be unaffected.
		FAIL_PREREQS)
			;;
		*)
			return
		esac
	fi

	case "$1" in
	!*)
		test_unset_prereq "${1#!}"
		;;
	*)
		satisfied_prereq="$satisfied_prereq$1 "
		;;
	esac
}
satisfied_prereq=" "
lazily_testable_prereq= lazily_tested_prereq=

# Usage: test_lazy_prereq PREREQ 'script'
test_lazy_prereq () {
	lazily_testable_prereq="$lazily_testable_prereq$1 "
	eval test_prereq_lazily_$1=\$2
}

test_run_lazy_prereq_ () {
	script='
mkdir -p "$TRASH_DIRECTORY/prereq-test-dir-'"$1"'" &&
(
	cd "$TRASH_DIRECTORY/prereq-test-dir-'"$1"'" &&'"$2"'
)'
	say >&3 "checking prerequisite: $1"
	say >&3 "$script"
	test_eval_ "$script"
	eval_ret=$?
	rm -rf "$TRASH_DIRECTORY/prereq-test-dir-$1"
	if test "$eval_ret" = 0; then
		say >&3 "prerequisite $1 ok"
	else
		say >&3 "prerequisite $1 not satisfied"
	fi
	return $eval_ret
}

test_have_prereq () {
	# prerequisites can be concatenated with ','
	save_IFS=$IFS
	IFS=,
	set -- $*
	IFS=$save_IFS

	total_prereq=0
	ok_prereq=0
	missing_prereq=

	for prerequisite
	do
		case "$prerequisite" in
		!*)
			negative_prereq=t
			prerequisite=${prerequisite#!}
			;;
		*)
			negative_prereq=
		esac

		case " $lazily_tested_prereq " in
		*" $prerequisite "*)
			;;
		*)
			case " $lazily_testable_prereq " in
			*" $prerequisite "*)
				eval "script=\$test_prereq_lazily_$prerequisite" &&
				if test_run_lazy_prereq_ "$prerequisite" "$script"
				then
					test_set_prereq $prerequisite
				fi
				lazily_tested_prereq="$lazily_tested_prereq$prerequisite "
			esac
			;;
		esac

		total_prereq=$(($total_prereq + 1))
		case "$satisfied_prereq" in
		*" $prerequisite "*)
			satisfied_this_prereq=t
			;;
		*)
			satisfied_this_prereq=
		esac

		case "$satisfied_this_prereq,$negative_prereq" in
		t,|,t)
			ok_prereq=$(($ok_prereq + 1))
			;;
		*)
			# Keep a list of missing prerequisites; restore
			# the negative marker if necessary.
			prerequisite=${negative_prereq:+!}$prerequisite

			# Abort if this prereq was marked as required
			if test -n "$GIT_TEST_REQUIRE_PREREQ"
			then
				case " $GIT_TEST_REQUIRE_PREREQ " in
				*" $prerequisite "*)
					BAIL_OUT "required prereq $prerequisite failed"
					;;
				esac
			fi

			if test -z "$missing_prereq"
			then
				missing_prereq=$prerequisite
			else
				missing_prereq="$prerequisite,$missing_prereq"
			fi
		esac
	done

	test $total_prereq = $ok_prereq
}

test_declared_prereq () {
	case ",$test_prereq," in
	*,$1,*)
		return 0
		;;
	esac
	return 1
}

test_verify_prereq () {
	test -z "$test_prereq" ||
	expr >/dev/null "$test_prereq" : '[A-Z0-9_,!]*$' ||
	BUG "'$test_prereq' does not look like a prereq"
}

test_expect_failure () {
	test_start_ "$@"
	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
	test "$#" = 2 ||
	BUG "not 2 or 3 parameters to test-expect-failure"
	test_verify_prereq
	export test_prereq
	if ! test_skip "$@"
	then
		test -n "$test_skip_test_preamble" ||
		say >&3 "checking known breakage of $TEST_NUMBER.$test_count '$1': $2"
		if test_run_ "$2" expecting_failure
		then
			test_known_broken_ok_ "$1"
		else
			test_known_broken_failure_ "$1"
		fi
	fi
	test_finish_
}

test_expect_success () {
	test_start_ "$@"
	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
	test "$#" = 2 ||
	BUG "not 2 or 3 parameters to test-expect-success"
	test_verify_prereq
	export test_prereq
	if ! test_skip "$@"
	then
		test -n "$test_skip_test_preamble" ||
		say >&3 "expecting success of $TEST_NUMBER.$test_count '$1': $2"
		if test_run_ "$2"
		then
			test_ok_ "$1"
		else
			test_failure_ "$@"
		fi
	fi
	test_finish_
}

# debugging-friendly alternatives to "test [-f|-d|-e]"
# The commands test the existence or non-existence of $1
test_path_is_file () {
	test "$#" -ne 1 && BUG "1 param"
	if ! test -f "$1"
	then
		echo "File $1 doesn't exist"
		false
	fi
}

test_path_is_file_not_symlink () {
	test "$#" -ne 1 && BUG "1 param"
	test_path_is_file "$1" &&
	if test -h "$1"
	then
		echo "$1 shouldn't be a symbolic link"
		false
	fi
}

test_path_is_dir () {
	test "$#" -ne 1 && BUG "1 param"
	if ! test -d "$1"
	then
		echo "Directory $1 doesn't exist"
		false
	fi
}

test_path_is_dir_not_symlink () {
	test "$#" -ne 1 && BUG "1 param"
	test_path_is_dir "$1" &&
	if test -h "$1"
	then
		echo "$1 shouldn't be a symbolic link"
		false
	fi
}

test_path_exists () {
	test "$#" -ne 1 && BUG "1 param"
	if ! test -e "$1"
	then
		echo "Path $1 doesn't exist"
		false
	fi
}

test_path_is_symlink () {
	test "$#" -ne 1 && BUG "1 param"
	if ! test -h "$1"
	then
		echo "Symbolic link $1 doesn't exist"
		false
	fi
}

# Check if the directory exists and is empty as expected, barf otherwise.
test_dir_is_empty () {
	test "$#" -ne 1 && BUG "1 param"
	test_path_is_dir "$1" &&
	if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
	then
		echo "Directory '$1' is not empty, it contains:"
		ls -la "$1"
		return 1
	fi
}

# Check if the file exists and has a size greater than zero
test_file_not_empty () {
	test "$#" = 2 && BUG "2 param"
	if ! test -s "$1"
	then
		echo "'$1' is not a non-empty file."
		false
	fi
}

test_path_is_missing () {
	test "$#" -ne 1 && BUG "1 param"
	if test -e "$1"
	then
		echo "Path exists:"
		ls -ld "$1"
		if test $# -ge 1
		then
			echo "$*"
		fi
		false
	fi
}

# test_line_count checks that a file has the number of lines it
# ought to. For example:
#
#	test_expect_success 'produce exactly one line of output' '
#		do something >output &&
#		test_line_count = 1 output
#	'
#
# is like "test $(wc -l <output) = 1" except that it passes the
# output through when the number of lines is wrong.

test_line_count () {
	if test $# != 3
	then
		BUG "not 3 parameters to test_line_count"
	elif ! test $(wc -l <"$3") "$1" "$2"
	then
		echo "test_line_count: line count for $3 !$1 $2"
		cat "$3"
		return 1
	fi
}

# SYNOPSIS:
# 	test_stdout_line_count <bin-ops> <value> <cmd> [<args>...]
#
# test_stdout_line_count checks that the output of a command has the number
# of lines it ought to. For example:
#
# test_stdout_line_count = 3 git ls-files -u
# test_stdout_line_count -gt 10 ls
test_stdout_line_count () {
	local ops val trashdir &&
	if test "$#" -le 3
	then
		BUG "expect 3 or more arguments"
	fi &&
	ops="$1" &&
	val="$2" &&
	shift 2 &&
	if ! trashdir="$(git rev-parse --git-dir)/trash"; then
		BUG "expect to be run inside a worktree"
	fi &&
	mkdir -p "$trashdir" &&
	"$@" >"$trashdir/output" &&
	test_line_count "$ops" "$val" "$trashdir/output"
}


test_file_size () {
	test "$#" -ne 1 && BUG "1 param"
	test-tool path-utils file-size "$1"
}

# Returns success if a comma separated string of keywords ($1) contains a
# given keyword ($2).
# Examples:
# `list_contains "foo,bar" bar` returns 0
# `list_contains "foo" bar` returns 1

list_contains () {
	case ",$1," in
	*,$2,*)
		return 0
		;;
	esac
	return 1
}

# Returns success if the arguments indicate that a command should be
# accepted by test_must_fail(). If the command is run with env, the env
# and its corresponding variable settings will be stripped before we
# test the command being run.
test_must_fail_acceptable () {
	if test "$1" = "env"
	then
		shift
		while test $# -gt 0
		do
			case "$1" in
			*?=*)
				shift
				;;
			*)
				break
				;;
			esac
		done
	fi

	case "$1" in
	git|__git*|test-tool|test_terminal)
		return 0
		;;
	*)
		return 1
		;;
	esac
}

# This is not among top-level (test_expect_success | test_expect_failure)
# but is a prefix that can be used in the test script, like:
#
#	test_expect_success 'complain and die' '
#           do something &&
#           do something else &&
#	    test_must_fail git checkout ../outerspace
#	'
#
# Writing this as "! git checkout ../outerspace" is wrong, because
# the failure could be due to a segv.  We want a controlled failure.
#
# Accepts the following options:
#
#   ok=<signal-name>[,<...>]:
#     Don't treat an exit caused by the given signal as error.
#     Multiple signals can be specified as a comma separated list.
#     Currently recognized signal names are: sigpipe, success.
#     (Don't use 'success', use 'test_might_fail' instead.)
#
# Do not use this to run anything but "git" and other specific testable
# commands (see test_must_fail_acceptable()).  We are not in the
# business of vetting system supplied commands -- in other words, this
# is wrong:
#
#    test_must_fail grep pattern output
#
# Instead use '!':
#
#    ! grep pattern output

test_must_fail () {
	case "$1" in
	ok=*)
		_test_ok=${1#ok=}
		shift
		;;
	*)
		_test_ok=
		;;
	esac
	if ! test_must_fail_acceptable "$@"
	then
		echo >&7 "test_must_fail: only 'git' is allowed: $*"
		return 1
	fi
	"$@" 2>&7
	exit_code=$?
	if test $exit_code -eq 0 && ! list_contains "$_test_ok" success
	then
		echo >&4 "test_must_fail: command succeeded: $*"
		return 1
	elif test_match_signal 13 $exit_code && list_contains "$_test_ok" sigpipe
	then
		return 0
	elif test $exit_code -gt 129 && test $exit_code -le 192
	then
		echo >&4 "test_must_fail: died by signal $(($exit_code - 128)): $*"
		return 1
	elif test $exit_code -eq 127
	then
		echo >&4 "test_must_fail: command not found: $*"
		return 1
	elif test $exit_code -eq 126
	then
		echo >&4 "test_must_fail: valgrind error: $*"
		return 1
	fi
	return 0
} 7>&2 2>&4

# Similar to test_must_fail, but tolerates success, too.  This is
# meant to be used in contexts like:
#
#	test_expect_success 'some command works without configuration' '
#		test_might_fail git config --unset all.configuration &&
#		do something
#	'
#
# Writing "git config --unset all.configuration || :" would be wrong,
# because we want to notice if it fails due to segv.
#
# Accepts the same options as test_must_fail.

test_might_fail () {
	test_must_fail ok=success "$@" 2>&7
} 7>&2 2>&4

# Similar to test_must_fail and test_might_fail, but check that a
# given command exited with a given exit code. Meant to be used as:
#
#	test_expect_success 'Merge with d/f conflicts' '
#		test_expect_code 1 git merge "merge msg" B master
#	'

test_expect_code () {
	want_code=$1
	shift
	"$@" 2>&7
	exit_code=$?
	if test $exit_code = $want_code
	then
		return 0
	fi

	echo >&4 "test_expect_code: command exited with $exit_code, we wanted $want_code $*"
	return 1
} 7>&2 2>&4

# test_cmp is a helper function to compare actual and expected output.
# You can use it like:
#
#	test_expect_success 'foo works' '
#		echo expected >expected &&
#		foo >actual &&
#		test_cmp expected actual
#	'
#
# This could be written as either "cmp" or "diff -u", but:
# - cmp's output is not nearly as easy to read as diff -u
# - not all diff versions understand "-u"

test_cmp () {
	test "$#" -ne 2 && BUG "2 param"
	eval "$GIT_TEST_CMP" '"$@"'
}

# Check that the given config key has the expected value.
#
#    test_cmp_config [-C <dir>] <expected-value>
#                    [<git-config-options>...] <config-key>
#
# for example to check that the value of core.bar is foo
#
#    test_cmp_config foo core.bar
#
test_cmp_config () {
	local GD &&
	if test "$1" = "-C"
	then
		shift &&
		GD="-C $1" &&
		shift
	fi &&
	printf "%s\n" "$1" >expect.config &&
	shift &&
	git $GD config "$@" >actual.config &&
	test_cmp expect.config actual.config
}

# test_cmp_bin - helper to compare binary files

test_cmp_bin () {
	test "$#" -ne 2 && BUG "2 param"
	cmp "$@"
}

# Wrapper for grep which used to be used for
# GIT_TEST_GETTEXT_POISON=false. Only here as a shim for other
# in-flight changes. Should not be used and will be removed soon.
test_i18ngrep () {
	eval "last_arg=\${$#}"

	test -f "$last_arg" ||
	BUG "test_i18ngrep requires a file to read as the last parameter"

	if test $# -lt 2 ||
	   { test "x!" = "x$1" && test $# -lt 3 ; }
	then
		BUG "too few parameters to test_i18ngrep"
	fi

	if test "x!" = "x$1"
	then
		shift
		! grep "$@" && return 0

		echo >&4 "error: '! grep $@' did find a match in:"
	else
		grep "$@" && return 0

		echo >&4 "error: 'grep $@' didn't find a match in:"
	fi

	if test -s "$last_arg"
	then
		cat >&4 "$last_arg"
	else
		echo >&4 "<File '$last_arg' is empty>"
	fi

	return 1
}

# Call any command "$@" but be more verbose about its
# failure. This is handy for commands like "test" which do
# not output anything when they fail.
verbose () {
	"$@" && return 0
	echo >&4 "command failed: $(git rev-parse --sq-quote "$@")"
	return 1
}

# Check if the file expected to be empty is indeed empty, and barfs
# otherwise.

test_must_be_empty () {
	test "$#" -ne 1 && BUG "1 param"
	test_path_is_file "$1" &&
	if test -s "$1"
	then
		echo "'$1' is not empty, it contains:"
		cat "$1"
		return 1
	fi
}

# Tests that its two parameters refer to the same revision, or if '!' is
# provided first, that its other two parameters refer to different
# revisions.
test_cmp_rev () {
	local op='=' wrong_result=different

	if test $# -ge 1 && test "x$1" = 'x!'
	then
	    op='!='
	    wrong_result='the same'
	    shift
	fi
	if test $# != 2
	then
		BUG "test_cmp_rev requires two revisions, but got $#"
	else
		local r1 r2
		r1=$(git rev-parse --verify "$1") &&
		r2=$(git rev-parse --verify "$2") || return 1

		if ! test "$r1" "$op" "$r2"
		then
			cat >&4 <<-EOF
			error: two revisions point to $wrong_result objects:
			  '$1': $r1
			  '$2': $r2
			EOF
			return 1
		fi
	fi
}

# Compare paths respecting core.ignoreCase
test_cmp_fspath () {
	if test "x$1" = "x$2"
	then
		return 0
	fi

	if test true != "$(git config --get --type=bool core.ignorecase)"
	then
		return 1
	fi

	test "x$(echo "$1" | tr A-Z a-z)" =  "x$(echo "$2" | tr A-Z a-z)"
}

# Print a sequence of integers in increasing order, either with
# two arguments (start and end):
#
#     test_seq 1 5 -- outputs 1 2 3 4 5 one line at a time
#
# or with one argument (end), in which case it starts counting
# from 1.

test_seq () {
	case $# in
	1)	set 1 "$@" ;;
	2)	;;
	*)	BUG "not 1 or 2 parameters to test_seq" ;;
	esac
	test_seq_counter__=$1
	while test "$test_seq_counter__" -le "$2"
	do
		echo "$test_seq_counter__"
		test_seq_counter__=$(( $test_seq_counter__ + 1 ))
	done
}

# This function can be used to schedule some commands to be run
# unconditionally at the end of the test to restore sanity:
#
#	test_expect_success 'test core.capslock' '
#		git config core.capslock true &&
#		test_when_finished "git config --unset core.capslock" &&
#		hello world
#	'
#
# That would be roughly equivalent to
#
#	test_expect_success 'test core.capslock' '
#		git config core.capslock true &&
#		hello world
#		git config --unset core.capslock
#	'
#
# except that the greeting and config --unset must both succeed for
# the test to pass.
#
# Note that under --immediate mode, no clean-up is done to help diagnose
# what went wrong.

test_when_finished () {
	# We cannot detect when we are in a subshell in general, but by
	# doing so on Bash is better than nothing (the test will
	# silently pass on other shells).
	test "${BASH_SUBSHELL-0}" = 0 ||
	BUG "test_when_finished does nothing in a subshell"
	test_cleanup="{ $*
		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_cleanup"
}

# This function can be used to schedule some commands to be run
# unconditionally at the end of the test script, e.g. to stop a daemon:
#
#	test_expect_success 'test git daemon' '
#		git daemon &
#		daemon_pid=$! &&
#		test_atexit 'kill $daemon_pid' &&
#		hello world
#	'
#
# The commands will be executed before the trash directory is removed,
# i.e. the atexit commands will still be able to access any pidfiles or
# socket files.
#
# Note that these commands will be run even when a test script run
# with '--immediate' fails.  Be careful with your atexit commands to
# minimize any changes to the failed state.

test_atexit () {
	# We cannot detect when we are in a subshell in general, but by
	# doing so on Bash is better than nothing (the test will
	# silently pass on other shells).
	test "${BASH_SUBSHELL-0}" = 0 ||
	BUG "test_atexit does nothing in a subshell"
	test_atexit_cleanup="{ $*
		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_atexit_cleanup"
}

# Deprecated wrapper for "git init", use "git init" directly instead
# Usage: test_create_repo <directory>
test_create_repo () {
	git init "$@"
}

# This function helps on symlink challenged file systems when it is not
# important that the file system entry is a symbolic link.
# Use test_ln_s_add instead of "ln -s x y && git add y" to add a
# symbolic link entry y to the index.

test_ln_s_add () {
	if test_have_prereq SYMLINKS
	then
		ln -s "$1" "$2" &&
		git update-index --add "$2"
	else
		printf '%s' "$1" >"$2" &&
		ln_s_obj=$(git hash-object -w "$2") &&
		git update-index --add --cacheinfo 120000 $ln_s_obj "$2" &&
		# pick up stat info from the file
		git update-index "$2"
	fi
}

# This function writes out its parameters, one per line
test_write_lines () {
	printf "%s\n" "$@"
}

perl () {
	command "$PERL_PATH" "$@" 2>&7
} 7>&2 2>&4

# Given the name of an environment variable with a bool value, normalize
# its value to a 0 (true) or 1 (false or empty string) return code.
#
#   test_bool_env GIT_TEST_HTTPD <default-value>
#
# Return with code corresponding to the given default value if the variable
# is unset.
# Abort the test script if either the value of the variable or the default
# are not valid bool values.

test_bool_env () {
	if test $# != 2
	then
		BUG "test_bool_env requires two parameters (variable name and default value)"
	fi

	git env--helper --type=bool --default="$2" --exit-code "$1"
	ret=$?
	case $ret in
	0|1)	# unset or valid bool value
		;;
	*)	# invalid bool value or something unexpected
		error >&7 "test_bool_env requires bool values both for \$$1 and for the default fallback"
		;;
	esac
	return $ret
}

# Exit the test suite, either by skipping all remaining tests or by
# exiting with an error. If our prerequisite variable $1 falls back
# on a default assume we were opportunistically trying to set up some
# tests and we skip. If it is explicitly "true", then we report a failure.
#
# The error/skip message should be given by $2.
#
test_skip_or_die () {
	if ! test_bool_env "$1" false
	then
		skip_all=$2
		test_done
	fi
	error "$2"
}

# Like "env FOO=BAR some-program", but run inside a subshell, which means
# it also works for shell functions (though those functions cannot impact
# the environment outside of the test_env invocation).
test_env () {
	(
		while test $# -gt 0
		do
			case "$1" in
			*=*)
				eval "${1%%=*}=\${1#*=}"
				eval "export ${1%%=*}"
				shift
				;;
			*)
				"$@" 2>&7
				exit
				;;
			esac
		done
	)
} 7>&2 2>&4

# Returns true if the numeric exit code in "$2" represents the expected signal
# in "$1". Signals should be given numerically.
test_match_signal () {
	if test "$2" = "$((128 + $1))"
	then
		# POSIX
		return 0
	elif test "$2" = "$((256 + $1))"
	then
		# ksh
		return 0
	fi
	return 1
}

# Read up to "$1" bytes (or to EOF) from stdin and write them to stdout.
test_copy_bytes () {
	perl -e '
		my $len = $ARGV[1];
		while ($len > 0) {
			my $s;
			my $nread = sysread(STDIN, $s, $len);
			die "cannot read: $!" unless defined($nread);
			last unless $nread;
			print $s;
			$len -= $nread;
		}
	' - "$1"
}

# run "$@" inside a non-git directory
nongit () {
	test -d non-repo ||
	mkdir non-repo ||
	return 1

	(
		GIT_CEILING_DIRECTORIES=$(pwd) &&
		export GIT_CEILING_DIRECTORIES &&
		cd non-repo &&
		"$@" 2>&7
	)
} 7>&2 2>&4

# These functions are historical wrappers around "test-tool pkt-line"
# for older tests. Use "test-tool pkt-line" itself in new tests.
packetize () {
	if test $# -gt 0
	then
		packet="$*"
		printf '%04x%s' "$((4 + ${#packet}))" "$packet"
	else
		test-tool pkt-line pack
	fi
}

packetize_raw () {
	test-tool pkt-line pack-raw-stdin
}

depacketize () {
	test-tool pkt-line unpack
}

# Converts base-16 data into base-8. The output is given as a sequence of
# escaped octals, suitable for consumption by 'printf'.
hex2oct () {
	perl -ne 'printf "\\%03o", hex for /../g'
}

# Set the hash algorithm in use to $1.  Only useful when testing the testsuite.
test_set_hash () {
	test_hash_algo="$1"
}

# Detect the hash algorithm in use.
test_detect_hash () {
	test_hash_algo="${GIT_TEST_DEFAULT_HASH:-sha1}"
}

# Load common hash metadata and common placeholder object IDs for use with
# test_oid.
test_oid_init () {
	test -n "$test_hash_algo" || test_detect_hash &&
	test_oid_cache <"$TEST_DIRECTORY/oid-info/hash-info" &&
	test_oid_cache <"$TEST_DIRECTORY/oid-info/oid"
}

# Load key-value pairs from stdin suitable for use with test_oid.  Blank lines
# and lines starting with "#" are ignored.  Keys must be shell identifier
# characters.
#
# Examples:
# rawsz sha1:20
# rawsz sha256:32
test_oid_cache () {
	local tag rest k v &&

	{ test -n "$test_hash_algo" || test_detect_hash; } &&
	while read tag rest
	do
		case $tag in
		\#*)
			continue;;
		?*)
			# non-empty
			;;
		*)
			# blank line
			continue;;
		esac &&

		k="${rest%:*}" &&
		v="${rest#*:}" &&

		if ! expr "$k" : '[a-z0-9][a-z0-9]*$' >/dev/null
		then
			BUG 'bad hash algorithm'
		fi &&
		eval "test_oid_${k}_$tag=\"\$v\""
	done
}

# Look up a per-hash value based on a key ($1).  The value must have been loaded
# by test_oid_init or test_oid_cache.
test_oid () {
	local algo="${test_hash_algo}" &&

	case "$1" in
	--hash=*)
		algo="${1#--hash=}" &&
		shift;;
	*)
		;;
	esac &&

	local var="test_oid_${algo}_$1" &&

	# If the variable is unset, we must be missing an entry for this
	# key-hash pair, so exit with an error.
	if eval "test -z \"\${$var+set}\""
	then
		BUG "undefined key '$1'"
	fi &&
	eval "printf '%s' \"\${$var}\""
}

# Insert a slash into an object ID so it can be used to reference a location
# under ".git/objects".  For example, "deadbeef..." becomes "de/adbeef..".
test_oid_to_path () {
	local basename=${1#??}
	echo "${1%$basename}/$basename"
}

# Parse oids from git ls-files --staged output
test_parse_ls_files_stage_oids () {
	awk '{print $2}' -
}

# Parse oids from git ls-tree output
test_parse_ls_tree_oids () {
	awk '{print $3}' -
}

# Choose a port number based on the test script's number and store it in
# the given variable name, unless that variable already contains a number.
test_set_port () {
	local var=$1 port

	if test $# -ne 1 || test -z "$var"
	then
		BUG "test_set_port requires a variable name"
	fi

	eval port=\$$var
	case "$port" in
	"")
		# No port is set in the given env var, use the test
		# number as port number instead.
		# Remove not only the leading 't', but all leading zeros
		# as well, so the arithmetic below won't (mis)interpret
		# a test number like '0123' as an octal value.
		port=${this_test#${this_test%%[1-9]*}}
		if test "${port:-0}" -lt 1024
		then
			# root-only port, use a larger one instead.
			port=$(($port + 10000))
		fi
		;;
	*[!0-9]*|0*)
		error >&7 "invalid port number: $port"
		;;
	*)
		# The user has specified the port.
		;;
	esac

	# Make sure that parallel '--stress' test jobs get different
	# ports.
	port=$(($port + ${GIT_TEST_STRESS_JOB_NR:-0}))
	eval $var=$port
}

# Tests for the hidden file attribute on Windows
test_path_is_hidden () {
	test_have_prereq MINGW ||
	BUG "test_path_is_hidden can only be used on Windows"

	# Use the output of `attrib`, ignore the absolute path
	case "$("$SYSTEMROOT"/system32/attrib "$1")" in *H*?:*) return 0;; esac
	return 1
}

# Check that the given command was invoked as part of the
# trace2-format trace on stdin.
#
#	test_subcommand [!] <command> <args>... < <trace>
#
# For example, to look for an invocation of "git upload-pack
# /path/to/repo"
#
#	GIT_TRACE2_EVENT=event.log git fetch ... &&
#	test_subcommand git upload-pack "$PATH" <event.log
#
# If the first parameter passed is !, this instead checks that
# the given command was not called.
#
test_subcommand () {
	local negate=
	if test "$1" = "!"
	then
		negate=t
		shift
	fi

	local expr=$(printf '"%s",' "$@")
	expr="${expr%,}"

	if test -n "$negate"
	then
		! grep "\[$expr\]"
	else
		grep "\[$expr\]"
	fi
}

# Check that the given command was invoked as part of the
# trace2-format trace on stdin.
#
#	test_region [!] <category> <label> git <command> <args>...
#
# For example, to look for trace2_region_enter("index", "do_read_index", repo)
# in an invocation of "git checkout HEAD~1", run
#
#	GIT_TRACE2_EVENT="$(pwd)/trace.txt" GIT_TRACE2_EVENT_NESTING=10 \
#		git checkout HEAD~1 &&
#	test_region index do_read_index <trace.txt
#
# If the first parameter passed is !, this instead checks that
# the given region was not entered.
#
test_region () {
	local expect_exit=0
	if test "$1" = "!"
	then
		expect_exit=1
		shift
	fi

	grep -e	'"region_enter".*"category":"'"$1"'","label":"'"$2"\" "$3"
	exitcode=$?

	if test $exitcode != $expect_exit
	then
		return 1
	fi

	grep -e	'"region_leave".*"category":"'"$1"'","label":"'"$2"\" "$3"
	exitcode=$?

	if test $exitcode != $expect_exit
	then
		return 1
	fi

	return 0
}

# Print the destination of symlink(s) provided as arguments. Basically
# the same as the readlink command, but it's not available everywhere.
test_readlink () {
	perl -le 'print readlink($_) for @ARGV' "$@"
}

# Set mtime to a fixed "magic" timestamp in mid February 2009, before we
# run an operation that may or may not touch the file.  If the file was
# touched, its timestamp will not accidentally have such an old timestamp,
# as long as your filesystem clock is reasonably correct.  To verify the
# timestamp, follow up with test_is_magic_mtime.
#
# An optional increment to the magic timestamp may be specified as second
# argument.
test_set_magic_mtime () {
	local inc=${2:-0} &&
	local mtime=$((1234567890 + $inc)) &&
	test-tool chmtime =$mtime "$1" &&
	test_is_magic_mtime "$1" $inc
}

# Test whether the given file has the "magic" mtime set.  This is meant to
# be used in combination with test_set_magic_mtime.
#
# An optional increment to the magic timestamp may be specified as second
# argument.  Usually, this should be the same increment which was used for
# the associated test_set_magic_mtime.
test_is_magic_mtime () {
	local inc=${2:-0} &&
	local mtime=$((1234567890 + $inc)) &&
	echo $mtime >.git/test-mtime-expect &&
	test-tool chmtime --get "$1" >.git/test-mtime-actual &&
	test_cmp .git/test-mtime-expect .git/test-mtime-actual
	local ret=$?
	rm -f .git/test-mtime-expect
	rm -f .git/test-mtime-actual
	return $ret
}