#!/bin/sh
#
# Copyright (c) 2019 Stefan Sperling <stsp@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

. ./common.sh

test_diff_basic() {
	local testroot=`test_init diff_basic`
	local head_rev=`git_show_head $testroot/repo`

	got checkout $testroot/repo $testroot/wt > /dev/null
	ret="$?"
	if [ "$ret" != "0" ]; then
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "modified alpha" > $testroot/wt/alpha
	(cd $testroot/wt && got rm beta >/dev/null)
	echo "new file" > $testroot/wt/new
	(cd $testroot/wt && got add new >/dev/null)

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'alpha$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + alpha' >> $testroot/stdout.expected
	echo '--- alpha' >> $testroot/stdout.expected
	echo '+++ alpha' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '+modified alpha' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'beta$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + /dev/null' >> $testroot/stdout.expected
	echo '--- beta' >> $testroot/stdout.expected
	echo '+++ /dev/null' >> $testroot/stdout.expected
	echo '@@ -1 +0,0 @@' >> $testroot/stdout.expected
	echo '-beta' >> $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected

	(cd $testroot/wt && got diff > $testroot/stdout)
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# 'got diff' in a repository without any arguments is an error
	(cd $testroot/repo && got diff 2> $testroot/stderr)
	echo "got: no got work tree found" > $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		test_done "$testroot" "$ret"
		return 1
	fi

	# 'got diff' in a repository with two arguments requires that
	# both named objects exist
	(cd $testroot/repo && got diff $head_rev foo 2> $testroot/stderr)
	echo "got: foo: object not found" > $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		test_done "$testroot" "$ret"
		return 1
	fi

	# diff non-existent path
	(cd $testroot/wt && got diff nonexistent > $testroot/stdout \
		2> $testroot/stderr)

	echo -n > $testroot/stdout.expected
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "got: nonexistent: No such file or directory" \
		> $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "modified zeta" > $testroot/wt/epsilon/zeta

	# diff several paths in a work tree
	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'alpha$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + alpha' >> $testroot/stdout.expected
	echo '--- alpha' >> $testroot/stdout.expected
	echo '+++ alpha' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '+modified alpha' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i epsilon | grep 'zeta$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + epsilon/zeta' >> $testroot/stdout.expected
	echo '--- epsilon/zeta' >> $testroot/stdout.expected
	echo '+++ epsilon/zeta' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-zeta' >> $testroot/stdout.expected
	echo '+modified zeta' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'beta$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + /dev/null' >> $testroot/stdout.expected
	echo '--- beta' >> $testroot/stdout.expected
	echo '+++ /dev/null' >> $testroot/stdout.expected
	echo '@@ -1 +0,0 @@' >> $testroot/stdout.expected
	echo '-beta' >> $testroot/stdout.expected

	(cd $testroot/wt && got diff new alpha epsilon beta > $testroot/stdout)
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# a branch 'new' should not collide with path 'new' if more
	# than two arguments are passed
	got br -r $testroot/repo -c master new > /dev/null
	(cd $testroot/wt && got diff new alpha epsilon beta \
		> $testroot/stdout 2> $testroot/stderr)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# different order of arguments results in different output order
	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'alpha$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + alpha' >> $testroot/stdout.expected
	echo '--- alpha' >> $testroot/stdout.expected
	echo '+++ alpha' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '+modified alpha' >> $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i epsilon | grep 'zeta$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + epsilon/zeta' >> $testroot/stdout.expected
	echo '--- epsilon/zeta' >> $testroot/stdout.expected
	echo '+++ epsilon/zeta' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-zeta' >> $testroot/stdout.expected
	echo '+modified zeta' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'beta$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + /dev/null' >> $testroot/stdout.expected
	echo '--- beta' >> $testroot/stdout.expected
	echo '+++ /dev/null' >> $testroot/stdout.expected
	echo '@@ -1 +0,0 @@' >> $testroot/stdout.expected
	echo '-beta' >> $testroot/stdout.expected
	(cd $testroot/wt && got diff alpha new epsilon beta \
		> $testroot/stdout 2> $testroot/stderr)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# Two arguments are interpreted as objects if a colliding path exists
	echo master > $testroot/wt/master
	(cd $testroot/wt && got add master > /dev/null)
	(cd $testroot/wt && got diff master new > $testroot/stdout)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "diff refs/heads/master refs/heads/new" > $testroot/stdout.expected
	# diff between the branches is empty
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi
	# same without a work tree
	(cd $testroot/repo && got diff master new > $testroot/stdout)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "diff refs/heads/master refs/heads/new" > $testroot/stdout.expected
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi
	# same with -r argument
	got diff -r $testroot/repo master new > $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "diff refs/heads/master refs/heads/new" > $testroot/stdout.expected
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# -P can be used to force use of paths
	(cd $testroot/wt && got diff -P new master > $testroot/stdout)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + master' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ master' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+master' >> $testroot/stdout.expected
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# -P can only be used in a work tree
	got diff -r $testroot/repo -P new master 2> $testroot/stderr
	ret="$?"
	if [ "$ret" == "0" ]; then
		echo "diff succeeded unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "got: -P option can only be used when diffing a work tree" \
		> $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		test_done "$testroot" "$ret"
		return 1
	fi

	# a single argument which can be resolved to a path is not ambiguous
	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected
	(cd $testroot/wt && got diff new > $testroot/stdout)
	ret="$?"
	if [ "$ret" != "0" ]; then
		echo "diff failed unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	# diff with just one object ID argument results in
	# interpretation of argument as a path
	(cd $testroot/wt && got diff $head_rev 2> $testroot/stderr)
	ret="$?"
	if [ "$ret" = "0" ]; then
		echo "diff succeeded unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "got: $head_rev: No such file or directory" \
		> $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		test_done "$testroot" "$ret"
		return 1
	fi

	# diff with more than two object arguments results in
	# interpretation of arguments as paths
	(cd $testroot/wt && got diff new $head_rev master \
		> $testroot/stout 2> $testroot/stderr)
	ret="$?"
	if [ "$ret" = "0" ]; then
		echo "diff succeeded unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + new' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "got: $head_rev: No such file or directory" \
		> $testroot/stderr.expected
	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		return 1
	fi
	test_done "$testroot" "$ret"
}

test_diff_shows_conflict() {
	local testroot=`test_init diff_shows_conflict 1`

	echo "1" > $testroot/repo/numbers
	echo "2" >> $testroot/repo/numbers
	echo "3" >> $testroot/repo/numbers
	echo "4" >> $testroot/repo/numbers
	echo "5" >> $testroot/repo/numbers
	echo "6" >> $testroot/repo/numbers
	echo "7" >> $testroot/repo/numbers
	echo "8" >> $testroot/repo/numbers
	(cd $testroot/repo && git add numbers)
	git_commit $testroot/repo -m "added numbers file"
	local base_commit=`git_show_head $testroot/repo`

	got checkout $testroot/repo $testroot/wt > /dev/null
	ret="$?"
	if [ "$ret" != "0" ]; then
		test_done "$testroot" "$ret"
		return 1
	fi

	sed -i 's/2/22/' $testroot/repo/numbers
	sed -i 's/8/33/' $testroot/repo/numbers
	git_commit $testroot/repo -m "modified line 2"
	local head_rev=`git_show_head $testroot/repo`

	# modify lines 2 and 8 in conflicting ways
	sed -i 's/2/77/' $testroot/wt/numbers
	sed -i 's/8/88/' $testroot/wt/numbers

	echo "C  numbers" > $testroot/stdout.expected
	echo -n "Updated to refs/heads/master: $head_rev" \
		>> $testroot/stdout.expected
	echo >> $testroot/stdout.expected
	echo "Files with new merge conflicts: 1" >> $testroot/stdout.expected

	(cd $testroot/wt && got update > $testroot/stdout)

	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'numbers$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + numbers' >> $testroot/stdout.expected
	echo '--- numbers' >> $testroot/stdout.expected
	echo '+++ numbers' >> $testroot/stdout.expected
	echo '@@ -1,8 +1,20 @@' >> $testroot/stdout.expected
	echo ' 1' >> $testroot/stdout.expected
	echo "+<<<<<<< merged change: commit $head_rev" \
		>> $testroot/stdout.expected
	echo ' 22' >> $testroot/stdout.expected
	echo "+||||||| 3-way merge base: commit $base_commit" \
		>> $testroot/stdout.expected
	echo '+2' >> $testroot/stdout.expected
	echo '+=======' >> $testroot/stdout.expected
	echo '+77' >> $testroot/stdout.expected
	echo '+>>>>>>>' >> $testroot/stdout.expected
	echo ' 3' >> $testroot/stdout.expected
	echo ' 4' >> $testroot/stdout.expected
	echo ' 5' >> $testroot/stdout.expected
	echo ' 6' >> $testroot/stdout.expected
	echo ' 7' >> $testroot/stdout.expected
	echo "+<<<<<<< merged change: commit $head_rev" \
		>> $testroot/stdout.expected
	echo ' 33' >> $testroot/stdout.expected
	echo "+||||||| 3-way merge base: commit $base_commit" \
		>> $testroot/stdout.expected
	echo '+8' >> $testroot/stdout.expected
	echo '+=======' >> $testroot/stdout.expected
	echo '+88' >> $testroot/stdout.expected
	echo '+>>>>>>>' >> $testroot/stdout.expected

	(cd $testroot/wt && got diff > $testroot/stdout)

	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_tag() {
	local testroot=`test_init diff_tag`
	local commit_id0=`git_show_head $testroot/repo`
	local tag1=1.0.0
	local tag2=2.0.0

	echo "modified alpha" > $testroot/repo/alpha
	git_commit $testroot/repo -m "changed alpha"
	local commit_id1=`git_show_head $testroot/repo`

	(cd $testroot/repo && git tag -m "test" $tag1)

	echo "new file" > $testroot/repo/new
	(cd $testroot/repo && git add new)
	git_commit $testroot/repo -m "new file"
	local commit_id2=`git_show_head $testroot/repo`

	(cd $testroot/repo && git tag -m "test" $tag2)

	echo "diff $commit_id0 refs/tags/$tag1" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id0 -i | grep 'alpha$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'alpha$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo '--- alpha' >> $testroot/stdout.expected
	echo '+++ alpha' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '+modified alpha' >> $testroot/stdout.expected

	got diff -r $testroot/repo $commit_id0 $tag1 > $testroot/stdout
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "diff refs/tags/$tag1 refs/tags/$tag2" > $testroot/stdout.expected
	echo "blob - /dev/null" >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i -c $commit_id2 | grep 'new$' | \
		cut -d' ' -f 1 | tr -d '\n' >> $testroot/stdout.expected
	echo " (mode 644)" >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected

	got diff -r $testroot/repo $tag1 $tag2 > $testroot/stdout
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_lightweight_tag() {
	local testroot=`test_init diff_tag`
	local commit_id0=`git_show_head $testroot/repo`
	local tag1=1.0.0
	local tag2=2.0.0

	echo "modified alpha" > $testroot/repo/alpha
	git_commit $testroot/repo -m "changed alpha"
	local commit_id1=`git_show_head $testroot/repo`

	(cd $testroot/repo && git tag $tag1)

	echo "new file" > $testroot/repo/new
	(cd $testroot/repo && git add new)
	git_commit $testroot/repo -m "new file"
	local commit_id2=`git_show_head $testroot/repo`

	(cd $testroot/repo && git tag $tag2)

	echo "diff $commit_id0 refs/tags/$tag1" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id0 -i | grep 'alpha$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'alpha$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo '--- alpha' >> $testroot/stdout.expected
	echo '+++ alpha' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '+modified alpha' >> $testroot/stdout.expected

	got diff -r $testroot/repo $commit_id0 $tag1 > $testroot/stdout
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "diff refs/tags/$tag1 refs/tags/$tag2" > $testroot/stdout.expected
	echo "blob - /dev/null" >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i -c $commit_id2 | grep 'new$' | \
		cut -d' ' -f 1 | tr -d '\n' >> $testroot/stdout.expected
	echo " (mode 644)" >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ new' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+new file' >> $testroot/stdout.expected

	got diff -r $testroot/repo $tag1 $tag2 > $testroot/stdout
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_ignore_whitespace() {
	local testroot=`test_init diff_ignore_whitespace`
	local commit_id0=`git_show_head $testroot/repo`

	got checkout $testroot/repo $testroot/wt > /dev/null
	ret="$?"
	if [ "$ret" != "0" ]; then
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "alpha   " > $testroot/wt/alpha

	(cd $testroot/wt && got diff -w > $testroot/stdout)

	echo "diff $commit_id0 $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id0 -i | grep 'alpha$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + alpha' >> $testroot/stdout.expected

	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_submodule_of_same_repo() {
	local testroot=`test_init diff_submodule_of_same_repo`

	(cd $testroot && git clone -q repo repo2 >/dev/null)
	(cd $testroot/repo && git submodule -q add ../repo2)
	(cd $testroot/repo && git commit -q -m 'adding submodule')

	epsilon_id=$(got tree -r $testroot/repo -i | grep 'epsilon/$' | \
		cut -d ' ' -f 1)
	submodule_id=$(got tree -r $testroot/repo -i | grep 'repo2\$$' | \
		cut -d ' ' -f 1)

	# Attempt a (nonsensical) diff between a tree object and a submodule.
	# Currently fails with "wrong type of object" error
	got diff -r $testroot/repo $epsilon_id $submodule_id \
		> $testroot/stdout 2> $testroot/stderr
	ret="$?"
	if [ "$ret" = "0" ]; then
		echo "diff command succeeded unexpectedly" >&2
		test_done "$testroot" "1"
		return 1
	fi
	echo "got: wrong type of object" > $testroot/stderr.expected

	cmp -s $testroot/stderr.expected $testroot/stderr
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stderr.expected $testroot/stderr
		return 1
	fi
	test_done "$testroot" "$ret"
}

test_diff_symlinks_in_work_tree() {
	local testroot=`test_init diff_symlinks_in_work_tree`

	(cd $testroot/repo && ln -s alpha alpha.link)
	(cd $testroot/repo && ln -s epsilon epsilon.link)
	(cd $testroot/repo && ln -s /etc/passwd passwd.link)
	(cd $testroot/repo && ln -s ../beta epsilon/beta.link)
	(cd $testroot/repo && ln -s nonexistent nonexistent.link)
	(cd $testroot/repo && ln -s .got/foo dotgotfoo.link)
	(cd $testroot/repo && git add .)
	git_commit $testroot/repo -m "add symlinks"
	local commit_id1=`git_show_head $testroot/repo`

	got checkout $testroot/repo $testroot/wt > /dev/null
	ret="$?"
	if [ "$ret" != "0" ]; then
		test_done "$testroot" "$ret"
		return 1
	fi

	(cd $testroot/wt && ln -sf beta alpha.link)
	(cd $testroot/wt && ln -sfh gamma epsilon.link)
	(cd $testroot/wt && ln -sf ../gamma/delta epsilon/beta.link)
	echo -n '.got/bar' > $testroot/wt/dotgotfoo.link
	(cd $testroot/wt && got rm nonexistent.link > /dev/null)
	(cd $testroot/wt && ln -sf epsilon/zeta zeta.link)
	(cd $testroot/wt && got add zeta.link > /dev/null)
	(cd $testroot/wt && got diff > $testroot/stdout)

	echo "diff $commit_id1 $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'alpha.link@ -> alpha$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + alpha.link' >> $testroot/stdout.expected
	echo '--- alpha.link' >> $testroot/stdout.expected
	echo '+++ alpha.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+beta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'dotgotfoo.link@ -> .got/foo$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + dotgotfoo.link' >> $testroot/stdout.expected
	echo '--- dotgotfoo.link' >> $testroot/stdout.expected
	echo '+++ dotgotfoo.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-.got/foo' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+.got/bar' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i epsilon | \
		grep 'beta.link@ -> ../beta$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + epsilon/beta.link' >> $testroot/stdout.expected
	echo '--- epsilon/beta.link' >> $testroot/stdout.expected
	echo '+++ epsilon/beta.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-../beta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+../gamma/delta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'epsilon.link@ -> epsilon$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + epsilon.link' >> $testroot/stdout.expected
	echo '--- epsilon.link' >> $testroot/stdout.expected
	echo '+++ epsilon.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-epsilon' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+gamma' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'nonexistent.link@ -> nonexistent$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo 'file + /dev/null' >> $testroot/stdout.expected
	echo '--- nonexistent.link' >> $testroot/stdout.expected
	echo '+++ /dev/null' >> $testroot/stdout.expected
	echo '@@ -1 +0,0 @@' >> $testroot/stdout.expected
	echo '-nonexistent' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + zeta.link' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ zeta.link' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+epsilon/zeta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected

	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_symlinks_in_repo() {
	local testroot=`test_init diff_symlinks_in_repo`

	(cd $testroot/repo && ln -s alpha alpha.link)
	(cd $testroot/repo && ln -s epsilon epsilon.link)
	(cd $testroot/repo && ln -s /etc/passwd passwd.link)
	(cd $testroot/repo && ln -s ../beta epsilon/beta.link)
	(cd $testroot/repo && ln -s nonexistent nonexistent.link)
	(cd $testroot/repo && ln -s .got/foo dotgotfoo.link)
	(cd $testroot/repo && git add .)
	git_commit $testroot/repo -m "add symlinks"
	local commit_id1=`git_show_head $testroot/repo`

	(cd $testroot/repo && ln -sf beta alpha.link)
	(cd $testroot/repo && ln -sfh gamma epsilon.link)
	(cd $testroot/repo && ln -sf ../gamma/delta epsilon/beta.link)
	(cd $testroot/repo && ln -sf .got/bar $testroot/repo/dotgotfoo.link)
	(cd $testroot/repo && git rm -q nonexistent.link)
	(cd $testroot/repo && ln -sf epsilon/zeta zeta.link)
	(cd $testroot/repo && git add .)
	git_commit $testroot/repo -m "change symlinks"
	local commit_id2=`git_show_head $testroot/repo`

	got diff -r $testroot/repo $commit_id1 $commit_id2 > $testroot/stdout

	echo "diff $commit_id1 $commit_id2" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'alpha.link@ -> alpha$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id2 -i | \
		grep 'alpha.link@ -> beta$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo '--- alpha.link' >> $testroot/stdout.expected
	echo '+++ alpha.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-alpha' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+beta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'dotgotfoo.link@ -> .got/foo$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id2 -i | \
		grep 'dotgotfoo.link@ -> .got/bar$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo '--- dotgotfoo.link' >> $testroot/stdout.expected
	echo '+++ dotgotfoo.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-.got/foo' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+.got/bar' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i epsilon | \
		grep 'beta.link@ -> ../beta$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id2 -i epsilon | \
		grep 'beta.link@ -> ../gamma/delta$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo '--- epsilon/beta.link' >> $testroot/stdout.expected
	echo '+++ epsilon/beta.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-../beta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+../gamma/delta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'epsilon.link@ -> epsilon$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id2 -i | \
		grep 'epsilon.link@ -> gamma$' | \
		cut -d' ' -f 1 >> $testroot/stdout.expected
	echo '--- epsilon.link' >> $testroot/stdout.expected
	echo '+++ epsilon.link' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	echo '-epsilon' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo '+gamma' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id1 -i | \
		grep 'nonexistent.link@ -> nonexistent$' | \
		cut -d' ' -f 1 | sed -e 's/$/ (mode 120000)/' \
		>> $testroot/stdout.expected
	echo 'blob + /dev/null' >> $testroot/stdout.expected
	echo '--- nonexistent.link' >> $testroot/stdout.expected
	echo '+++ /dev/null' >> $testroot/stdout.expected
	echo '@@ -1 +0,0 @@' >> $testroot/stdout.expected
	echo '-nonexistent' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo -n 'blob + ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -c $commit_id2 -i | \
		grep 'zeta.link@ -> epsilon/zeta$' | \
		cut -d' ' -f 1 | sed -e 's/$/ (mode 120000)/' \
		>> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ zeta.link' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	echo '+epsilon/zeta' >> $testroot/stdout.expected
	echo '\ No newline at end of file' >> $testroot/stdout.expected

	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_diff_binary_files() {
	local testroot=`test_init diff_binary_files`
	local head_rev=`git_show_head $testroot/repo`

	got checkout $testroot/repo $testroot/wt > /dev/null
	ret="$?"
	if [ "$ret" != "0" ]; then
		test_done "$testroot" "$ret"
		return 1
	fi

	printf '\377\377\0\0\377\377\0\0' > $testroot/wt/foo
	(cd $testroot/wt && got add foo >/dev/null)

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + foo' >> $testroot/stdout.expected
	echo "Binary files /dev/null and foo differ" \
		>> $testroot/stdout.expected

	(cd $testroot/wt && got diff > $testroot/stdout)
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -a -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo 'blob - /dev/null' >> $testroot/stdout.expected
	echo 'file + foo' >> $testroot/stdout.expected
	echo '--- /dev/null' >> $testroot/stdout.expected
	echo '+++ foo' >> $testroot/stdout.expected
	echo '@@ -0,0 +1 @@' >> $testroot/stdout.expected
	printf '+\377\377\0\0\377\377\0\0\n' >> $testroot/stdout.expected
	printf '\\ No newline at end of file\n' >> $testroot/stdout.expected

	(cd $testroot/wt && got diff -a > $testroot/stdout)
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -a -u $testroot/stdout.expected $testroot/stdout
		test_done "$testroot" "$ret"
		return 1
	fi

	(cd $testroot/wt && got commit -m 'add binary file' > /dev/null)
	local head_rev=`git_show_head $testroot/repo`

	printf '\377\200\0\0\377\200\0\0' > $testroot/wt/foo

	echo "diff $head_rev $testroot/wt" > $testroot/stdout.expected
	echo -n 'blob - ' >> $testroot/stdout.expected
	got tree -r $testroot/repo -i | grep 'foo$' | cut -d' ' -f 1 \
		>> $testroot/stdout.expected
	echo 'file + foo' >> $testroot/stdout.expected
	echo '--- foo' >> $testroot/stdout.expected
	echo '+++ foo' >> $testroot/stdout.expected
	echo '@@ -1 +1 @@' >> $testroot/stdout.expected
	printf -- '-\377\377\0\0\377\377\0\0\n' >> $testroot/stdout.expected
	printf '\\ No newline at end of file\n' >> $testroot/stdout.expected
	printf '+\377\200\0\0\377\200\0\0\n' >> $testroot/stdout.expected
	printf '\\ No newline at end of file\n' >> $testroot/stdout.expected

	(cd $testroot/wt && got diff -a > $testroot/stdout)
	cmp -s $testroot/stdout.expected $testroot/stdout
	ret="$?"
	if [ "$ret" != "0" ]; then
		diff -a -u $testroot/stdout.expected $testroot/stdout
	fi
	test_done "$testroot" "$ret"
}

test_parseargs "$@"
run_test test_diff_basic
run_test test_diff_shows_conflict
run_test test_diff_tag
run_test test_diff_lightweight_tag
run_test test_diff_ignore_whitespace
run_test test_diff_submodule_of_same_repo
run_test test_diff_symlinks_in_work_tree
run_test test_diff_symlinks_in_repo
run_test test_diff_binary_files
