[PATCH 6/7] test-lib-functions: make test_todo support a --reset

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

As noted in the preceding commit that introduced "test_todo" we
couldn't run something like "git rm" since we run both the --want and
--expect variants, and if --want has removed a file the --expect won't
succeed.

Let's add a --reset option to the command, this allows us to convert a
test added in 03415ca8db2 (t3600: document failure of rm across
symbolic links, 2013-04-04) to a more exact "test_expect_todo".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/t3600-rm.sh           | 23 ++++++++++++++++++-----
 t/test-lib-functions.sh | 26 ++++++++++++++++++++++----
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index e74a318ac33..42879e9060b 100755
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -790,7 +790,7 @@ test_expect_success SYMLINKS 'rm across a symlinked leading path (no index)' '
 	test_path_is_file e/f
 '
 
-test_expect_failure SYMLINKS 'rm across a symlinked leading path (w/ index)' '
+test_expect_todo SYMLINKS 'rm across a symlinked leading path (w/ index)' '
 	rm -rf d e &&
 	mkdir d &&
 	echo content >d/f &&
@@ -798,10 +798,23 @@ test_expect_failure SYMLINKS 'rm across a symlinked leading path (w/ index)' '
 	git commit -m "d/f exists" &&
 	mv d e &&
 	ln -s e d &&
-	test_must_fail git rm d/f &&
-	git rev-parse --verify :d/f &&
-	test -h d &&
-	test_path_is_file e/f
+	test_todo \
+		--want "test_must_fail git" \
+		--reset "git reset --hard" \
+		--expect git \
+		-- \
+		rm d/f &&
+	test_todo \
+		--want git \
+		--expect "test_must_fail git" \
+		-- \
+		rev-parse --verify :d/f &&
+	test_todo \
+		--want "test -h" \
+		--expect "test_path_is_missing" \
+		-- \
+		d &&
+	todo_test_path is_file is_missing e/f
 '
 
 test_expect_success 'setup for testing rm messages' '
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 3febf4b0811..5313ab28e72 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -966,6 +966,10 @@ test_path_is_missing () {
 #	--expect <expect>
 #		The condition we have now. Injected in the same way as
 #		the arguments to --want.
+#	--reset <reset>
+#		A command to run between the <want> and <expect>
+#		conditions to reset the repository state. Used e.g. if
+#		both run a "git rm" command that might succeed.
 #
 # test_todo is a wrapper for use with "test_expect_todo". It declares
 # an outcome we want, and one we currently expect:
@@ -985,8 +989,12 @@ test_path_is_missing () {
 # Because we run both neither of them can mutate the test
 # state. I.e. they must be read-only commands such as "wc -l", and not
 # a state-altering command such as "rm".
+#
+# To run a command that mutates the repository state supply a --reset
+# option, e.g. "git reset --hard" if you need to run "git rm".
 test_todo () {
 	local common_fn= &&
+	local reset= &&
 	local have_want= &&
 	local want= &&
 	local expect= &&
@@ -1004,6 +1012,10 @@ test_todo () {
 			have_expect=t &&
 			shift
 			;;
+		--reset)
+			reset="$2" &&
+			shift
+			;;
 		--)
 			shift &&
 			break
@@ -1028,10 +1040,16 @@ test_todo () {
 	then
 		BUG "a test_todo succeeded with --want ('$want').  Turn it into a test_expect_success + $@ $want?" &&
 		return 1
-	elif $common_fn $expect "$@"
-	then
-		say "a test_todo will succeed with --expect ('$expect'), we eventually want '$want' instead" >&3 &&
-		return 0
+	else
+		if test -n "$reset"
+		then
+			$reset
+		fi &&
+		if $common_fn $expect "$@"
+		then
+			say "a test_todo will succeed with --expect ('$expect'), we eventually want '$want' instead" >&3 &&
+			return 0
+		fi
 	fi &&
 	BUG "a test_todo didn't pass with either --want ('$want') or --expect ('$expect')"
 }
-- 
2.35.1.1436.g756b814e59f