t: use test_decode_color rather than literal ANSI codes

When we put literal ANSI terminal codes into our test
scripts, it makes diffs on those scripts hard to read (the
colors may be indistinguishable from diff coloring, or in
the case of a reset, may not be visible at all).

Some scripts get around this by including human-readable
names and converting to literal codes with a git-config
hack. This makes the actual code diffs look OK, but test_cmp
output suffers from the same problem.

Let's use test_decode_color instead, which turns the codes
into obvious text tags.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4207-log-decoration-colors.sh

@@ -7,11 +7,6 @@ test_description='Test for "git log --decorate" colors'
 
 . ./test-lib.sh
 
-get_color ()
-{
-	git config --get-color no.such.slot "$1"
-}
-
 test_expect_success setup '
 	git config diff.color.commit yellow &&
 	git config color.decorate.branch green &&
@@ -20,14 +15,14 @@ test_expect_success setup '
 	git config color.decorate.stash magenta &&
 	git config color.decorate.HEAD cyan &&
 
-	c_reset=$(get_color reset) &&
+	c_reset="<RESET>" &&
 
-	c_commit=$(get_color yellow) &&
-	c_branch=$(get_color green) &&
-	c_remoteBranch=$(get_color red) &&
-	c_tag=$(get_color "reverse bold yellow") &&
-	c_stash=$(get_color magenta) &&
-	c_HEAD=$(get_color cyan) &&
+	c_commit="<YELLOW>" &&
+	c_branch="<GREEN>" &&
+	c_remoteBranch="<RED>" &&
+	c_tag="<BOLD;REVERSE;YELLOW>" &&
+	c_stash="<MAGENTA>" &&
+	c_HEAD="<CYAN>" &&
 
 	test_commit A &&
 	git clone . other &&
@@ -59,7 +54,8 @@ EOF
 # to this test since it does not contain any decoration, hence --first-parent
 test_expect_success 'Commit Decorations Colored Correctly' '
 	git log --first-parent --abbrev=10 --all --decorate --oneline --color=always |
-	sed "s/[0-9a-f]\{10,10\}/COMMIT_ID/" >out &&
+	sed "s/[0-9a-f]\{10,10\}/COMMIT_ID/" |
+	test_decode_color >out &&
 	test_cmp expected out
 '
 

t/t6006-rev-list-format.sh

@@ -61,8 +61,9 @@ test_format () {
 # Feed to --format to provide predictable colored sequences.
 AUTO_COLOR='%C(auto,red)foo%C(auto,reset)'
 has_color () {
-	printf '\033[31mfoo\033[m\n' >expect &&
-	test_cmp expect "$1"
+	test_decode_color <"$1" >decoded &&
+	echo "<RED>foo<RESET>" >expect &&
+	test_cmp expect decoded
 }
 
 has_no_color () {
@@ -170,19 +171,27 @@ $added
 
 EOF
 
-test_format colors %Credfoo%Cgreenbar%Cbluebaz%Cresetxyzzy <<EOF
-commit $head2
-foobarbazxyzzy
-commit $head1
-foobarbazxyzzy
-EOF
+test_expect_success 'basic colors' '
+	cat >expect <<-EOF &&
+	commit $head2
+	<RED>foo<GREEN>bar<BLUE>baz<RESET>xyzzy
+	EOF
+	format="%Credfoo%Cgreenbar%Cbluebaz%Cresetxyzzy" &&
+	git rev-list --format="$format" -1 master >actual.raw &&
+	test_decode_color <actual.raw >actual &&
+	test_cmp expect actual
+'
 
-test_format advanced-colors '%C(red yellow bold)foo%C(reset)' <<EOF
-commit $head2
-foo
-commit $head1
-foo
-EOF
+test_expect_success 'advanced colors' '
+	cat >expect <<-EOF &&
+	commit $head2
+	<BOLD;RED;BYELLOW>foo<RESET>
+	EOF
+	format="%C(red yellow bold)foo%C(reset)" &&
+	git rev-list --format="$format" -1 master >actual.raw &&
+	test_decode_color <actual.raw >actual &&
+	test_cmp expect actual
+'
 
 test_expect_success '%C(auto,...) does not enable color by default' '
 	git log --format=$AUTO_COLOR -1 >actual &&
@@ -224,8 +233,9 @@ test_expect_success '%C(auto,...) respects --color=auto (stdout not tty)' '
 '
 
 test_expect_success '%C(auto) respects --color' '
-	git log --color --format="%C(auto)%H" -1 >actual &&
-	printf "\\033[33m%s\\033[m\\n" $(git rev-parse HEAD) >expect &&
+	git log --color --format="%C(auto)%H" -1 >actual.raw &&
+	test_decode_color <actual.raw >actual &&
+	echo "<YELLOW>$(git rev-parse HEAD)<RESET>" >expect &&
 	test_cmp expect actual
 '
 

t/t6300-for-each-ref.sh

@@ -412,20 +412,18 @@ test_expect_success 'Check for invalid refname format' '
 	test_must_fail git for-each-ref --format="%(refname:INVALID)"
 '
 
-get_color ()
-{
-	git config --get-color no.such.slot "$1"
-}
-
 cat >expected <<EOF
-$(git rev-parse --short refs/heads/master) $(get_color green)master$(get_color reset)
-$(git rev-parse --short refs/remotes/origin/master) $(get_color green)origin/master$(get_color reset)
-$(git rev-parse --short refs/tags/testtag) $(get_color green)testtag$(get_color reset)
-$(git rev-parse --short refs/tags/two) $(get_color green)two$(get_color reset)
+$(git rev-parse --short refs/heads/master) <GREEN>master<RESET>
+$(git rev-parse --short refs/remotes/origin/master) <GREEN>origin/master<RESET>
+$(git rev-parse --short refs/tags/testtag) <GREEN>testtag<RESET>
+$(git rev-parse --short refs/tags/two) <GREEN>two<RESET>
 EOF
 
 test_expect_success 'Check %(color:...) ' '
-	git for-each-ref --format="%(objectname:short) %(color:green)%(refname:short)" >actual &&
+	git for-each-ref \
+		--format="%(objectname:short) %(color:green)%(refname:short)" \
+		>actual.raw &&
+	test_decode_color <actual.raw >actual &&
 	test_cmp expected actual
 '
 

t/test-lib-functions.sh

@@ -42,6 +42,7 @@ test_decode_color () {
 		function name(n) {
 			if (n == 0) return "RESET";
 			if (n == 1) return "BOLD";
+			if (n == 7) return "REVERSE";
 			if (n == 30) return "BLACK";
 			if (n == 31) return "RED";
 			if (n == 32) return "GREEN";