#!/bin/sh

test_description='Test diff-highlight'

CURR_DIR=$(pwd)
TEST_OUTPUT_DIRECTORY=$(pwd)
TEST_DIRECTORY="$CURR_DIR"/../../../t
DIFF_HIGHLIGHT="$CURR_DIR"/../diff-highlight

GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
. "$TEST_DIRECTORY"/test-lib.sh

if ! test_have_prereq PERL
then
	skip_all='skipping diff-highlight tests; perl not available'
	test_done
fi

# dh_test is a test helper function which takes 3 file names as parameters. The
# first 2 files are used to generate diff and commit output, which is then
# piped through diff-highlight. The 3rd file should contain the expected output
# of diff-highlight (minus the diff/commit header, ie. everything after and
# including the first @@ line).
dh_test () {
	a="$1" b="$2" &&

	cat >patch.exp &&

	{
		cat "$a" >file &&
		git add file &&
		git commit -m "Add a file" &&

		cat "$b" >file &&
		git diff file >diff.raw &&
		git commit -a -m "Update a file" &&
		git show >commit.raw
	} >/dev/null &&

	"$DIFF_HIGHLIGHT" <diff.raw >diff.hi &&
	test_strip_patch_header <diff.hi | test_decode_color >diff.act &&
	"$DIFF_HIGHLIGHT" <commit.raw >commit.hi &&
	test_strip_patch_header <commit.hi | test_decode_color >commit.act &&
	test_cmp patch.exp diff.act &&
	test_cmp patch.exp commit.act
}

test_strip_patch_header () {
	sed -n '/^@@/,$p' $*
}

# dh_test_setup_history generates a contrived graph such that we have at least
# 1 nesting (E) and 2 nestings (F).
#
#	  A---B master
#	 /
#	D---E---F branch
#
#	git log --all --graph
#	* commit
#	|    B
#	| * commit
#	| |    F
#	* | commit
#	| |    A
#	| * commit
#	|/
#	|    E
#	* commit
#	     D
#
dh_test_setup_history () {
	echo file1 >file &&
	git add file &&
	test_tick &&
	git commit -m "D" &&

	git checkout -b branch &&
	echo file2 >file &&
	test_tick &&
	git commit -a -m "E" &&

	git checkout master &&
	echo file2 >file &&
	test_tick &&
	git commit -a -m "A" &&

	git checkout branch &&
	echo file3 >file &&
	test_tick &&
	git commit -a -m "F" &&

	git checkout master &&
	echo file3 >file &&
	test_tick &&
	git commit -a -m "B"
}

left_trim () {
	"$PERL_PATH" -pe 's/^\s+//'
}

trim_graph () {
	# graphs start with * or |
	# followed by a space or / or \
	"$PERL_PATH" -pe 's@^((\*|\|)( |/|\\))+@@'
}

test_expect_success 'diff-highlight highlights the beginning of a line' '
	cat >a <<-\EOF &&
		aaa
		bbb
		ccc
	EOF

	cat >b <<-\EOF &&
		aaa
		0bb
		ccc
	EOF

	dh_test a b <<-EOF
		@@ -1,3 +1,3 @@
		 aaa
		-<REVERSE>b<NOREVERSE>bb
		+<REVERSE>0<NOREVERSE>bb
		 ccc
	EOF
'

test_expect_success 'diff-highlight highlights the end of a line' '
	cat >a <<-\EOF &&
		aaa
		bbb
		ccc
	EOF

	cat >b <<-\EOF &&
		aaa
		bb0
		ccc
	EOF

	dh_test a b <<-EOF
		@@ -1,3 +1,3 @@
		 aaa
		-bb<REVERSE>b<NOREVERSE>
		+bb<REVERSE>0<NOREVERSE>
		 ccc
	EOF
'

test_expect_success 'diff-highlight highlights the middle of a line' '
	cat >a <<-\EOF &&
		aaa
		bbb
		ccc
	EOF

	cat >b <<-\EOF &&
		aaa
		b0b
		ccc
	EOF

	dh_test a b <<-EOF
		@@ -1,3 +1,3 @@
		 aaa
		-b<REVERSE>b<NOREVERSE>b
		+b<REVERSE>0<NOREVERSE>b
		 ccc
	EOF
'

test_expect_success 'diff-highlight does not highlight whole line' '
	cat >a <<-\EOF &&
		aaa
		bbb
		ccc
	EOF

	cat >b <<-\EOF &&
		aaa
		000
		ccc
	EOF

	dh_test a b <<-EOF
		@@ -1,3 +1,3 @@
		 aaa
		-bbb
		+000
		 ccc
	EOF
'

test_expect_failure 'diff-highlight highlights mismatched hunk size' '
	cat >a <<-\EOF &&
		aaa
		bbb
	EOF

	cat >b <<-\EOF &&
		aaa
		b0b
		ccc
	EOF

	dh_test a b <<-EOF
		@@ -1,3 +1,3 @@
		 aaa
		-b<REVERSE>b<NOREVERSE>b
		+b<REVERSE>0<NOREVERSE>b
		+ccc
	EOF
'

# These two code points share the same leading byte in UTF-8 representation;
# a naive byte-wise diff would highlight only the second byte.
#
#   - U+00f3 ("o" with acute)
o_accent=$(printf '\303\263')
#   - U+00f8 ("o" with stroke)
o_stroke=$(printf '\303\270')

test_expect_success 'diff-highlight treats multibyte utf-8 as a unit' '
	echo "unic${o_accent}de" >a &&
	echo "unic${o_stroke}de" >b &&
	dh_test a b <<-EOF
		@@ -1 +1 @@
		-unic<REVERSE>${o_accent}<NOREVERSE>de
		+unic<REVERSE>${o_stroke}<NOREVERSE>de
	EOF
'

# Unlike the UTF-8 above, these are combining code points which are meant
# to modify the character preceding them:
#
#   - U+0301 (combining acute accent)
combine_accent=$(printf '\314\201')
#   - U+0302 (combining circumflex)
combine_circum=$(printf '\314\202')

test_expect_failure 'diff-highlight treats combining code points as a unit' '
	echo "unico${combine_accent}de" >a &&
	echo "unico${combine_circum}de" >b &&
	dh_test a b <<-EOF
		@@ -1 +1 @@
		-unic<REVERSE>o${combine_accent}<NOREVERSE>de
		+unic<REVERSE>o${combine_circum}<NOREVERSE>de
	EOF
'

test_expect_success 'diff-highlight works with the --graph option' '
	dh_test_setup_history &&

	# date-order so that the commits are interleaved for both
	# trim graph elements so we can do a diff
	# trim leading space because our trim_graph is not perfect
	git log --branches -p --date-order |
		"$DIFF_HIGHLIGHT" | left_trim >graph.exp &&
	git log --branches -p --date-order --graph |
		"$DIFF_HIGHLIGHT" | trim_graph | left_trim >graph.act &&
	test_cmp graph.exp graph.act
'

# Just reuse the previous graph test, but with --color.  Our trimming
# doesn't know about color, so just sanity check that something got
# highlighted.
test_expect_success 'diff-highlight works with color graph' '
	git log --branches -p --date-order --graph --color |
		"$DIFF_HIGHLIGHT" | trim_graph | left_trim >graph &&
	grep "\[7m" graph
'

# Most combined diffs won't meet diff-highlight's line-number filter. So we
# create one here where one side drops a line and the other modifies it. That
# should result in a diff like:
#
#    - modified content
#    ++resolved content
#
# which naively looks like one side added "+resolved".
test_expect_success 'diff-highlight ignores combined diffs' '
	echo "content" >file &&
	git add file &&
	git commit -m base &&

	>file &&
	git commit -am master &&

	git checkout -b other HEAD^ &&
	echo "modified content" >file &&
	git commit -am other &&

	test_must_fail git merge master &&
	echo "resolved content" >file &&
	git commit -am resolved &&

	cat >expect <<-\EOF &&
	--- a/file
	+++ b/file
	@@@ -1,1 -1,0 +1,1 @@@
	- modified content
	++resolved content
	EOF

	git show -c | "$DIFF_HIGHLIGHT" >actual.raw &&
	sed -n "/^---/,\$p" <actual.raw >actual &&
	test_cmp expect actual
'

test_expect_success 'diff-highlight handles --graph with leading dash' '
	cat >file <<-\EOF &&
	before
	the old line
	-leading dash
	EOF
	git add file &&
	git commit -m before &&

	sed s/old/new/ <file >file.tmp &&
	mv file.tmp file &&
	git add file &&
	git commit -m after &&

	cat >expect <<-EOF &&
	--- a/file
	+++ b/file
	@@ -1,3 +1,3 @@
	 before
	-the <REVERSE>old<NOREVERSE> line
	+the <REVERSE>new<NOREVERSE> line
	 -leading dash
	EOF
	git log --graph -p -1 | "$DIFF_HIGHLIGHT" >actual.raw &&
	trim_graph <actual.raw | sed -n "/^---/,\$p" | test_decode_color >actual &&
	test_cmp expect actual
'

test_expect_success 'highlight diff that removes final newline' '
	printf "content\n" >a &&
	printf "content" >b &&
	dh_test a b <<-\EOF
	@@ -1 +1 @@
	-content
	+content
	\ No newline at end of file
	EOF
'

test_expect_success 'configure set/reset colors' '
	test_config color.diff-highlight.oldhighlight bold &&
	test_config color.diff-highlight.oldreset nobold &&
	test_config color.diff-highlight.newhighlight italic &&
	test_config color.diff-highlight.newreset noitalic &&
	echo "prefix a suffix" >a &&
	echo "prefix b suffix" >b &&
	dh_test a b <<-\EOF
	@@ -1 +1 @@
	-prefix <BOLD>a<NORMAL_INTENSITY> suffix
	+prefix <ITALIC>b<NOITALIC> suffix
	EOF
'

test_expect_success 'configure normal/highlight colors' '
	test_config color.diff-highlight.oldnormal red &&
	test_config color.diff-highlight.oldhighlight magenta &&
	test_config color.diff-highlight.newnormal green &&
	test_config color.diff-highlight.newhighlight yellow &&
	echo "prefix a suffix" >a &&
	echo "prefix b suffix" >b &&
	dh_test a b <<-\EOF
	@@ -1 +1 @@
	<RED>-prefix <RESET><MAGENTA>a<RESET><RED> suffix<RESET>
	<GREEN>+prefix <RESET><YELLOW>b<RESET><GREEN> suffix<RESET>
	EOF
'

test_done
