1 files changed, 95 insertions, 0 deletions
diff --git a/t/lib-subtest.sh b/t/lib-subtest.sh
new file mode 100644
index 0000000000..56ee927f0c
--- /dev/null
+++ b/t/lib-subtest.sh
@@ -0,0 +1,95 @@
+write_sub_test_lib_test () {
+	name="$1" # stdin is the body of the test code
+	mkdir "$name" &&
+	write_script "$name/$name.sh" "$TEST_SHELL_PATH" <<-EOF &&
+	test_description='A test of test-lib.sh itself'
+
+	# Point to the t/test-lib.sh, which isn't in ../ as usual
+	. "\$TEST_DIRECTORY"/test-lib.sh
+	EOF
+	cat >>"$name/$name.sh"
+}
+
+_run_sub_test_lib_test_common () {
+	cmp_op="$1" want_code="$2" name="$3" # stdin is the body of the test code
+	shift 3
+
+	# intercept pseudo-options at the front of the argument list that we
+	# will not pass to child script
+	skip=
+	while test $# -gt 0
+	do
+		case "$1" in
+		--skip=*)
+			skip=${1#--*=}
+			shift
+			;;
+		*)
+			break
+			;;
+		esac
+	done
+
+	(
+		cd "$name" &&
+
+		# Pretend we're not running under a test harness, whether we
+		# are or not. The test-lib output depends on the setting of
+		# this variable, so we need a stable setting under which to run
+		# the sub-test.
+		sane_unset HARNESS_ACTIVE &&
+
+		export TEST_DIRECTORY &&
+		# The child test re-sources GIT-BUILD-OPTIONS and may thus
+		# override the test output directory. We thus pass it as an
+		# explicit override to the child.
+		TEST_OUTPUT_DIRECTORY_OVERRIDE=$(pwd) &&
+		export TEST_OUTPUT_DIRECTORY_OVERRIDE &&
+		GIT_SKIP_TESTS=$skip &&
+		export GIT_SKIP_TESTS &&
+		sane_unset GIT_TEST_FAIL_PREREQS &&
+		./"$name.sh" "$@" >out 2>err;
+		ret=$? &&
+		test "$ret" "$cmp_op" "$want_code"
+	)
+}
+
+write_and_run_sub_test_lib_test () {
+	name="$1" descr="$2" # stdin is the body of the test code
+	write_sub_test_lib_test "$@" || return 1
+	_run_sub_test_lib_test_common -eq 0 "$@"
+}
+
+write_and_run_sub_test_lib_test_err () {
+	name="$1" descr="$2" # stdin is the body of the test code
+	write_sub_test_lib_test "$@" || return 1
+	_run_sub_test_lib_test_common -eq 1 "$@"
+}
+
+run_sub_test_lib_test () {
+	_run_sub_test_lib_test_common -eq 0 "$@"
+}
+
+run_sub_test_lib_test_err () {
+	_run_sub_test_lib_test_common -eq 1 "$@"
+}
+
+_check_sub_test_lib_test_common () {
+	name="$1" &&
+	sed -e 's/^> //' -e 's/Z$//' >"$name"/expect.out &&
+	test_cmp "$name"/expect.out "$name"/out
+}
+
+check_sub_test_lib_test () {
+	name="$1" # stdin is the expected output from the test
+	_check_sub_test_lib_test_common "$name" &&
+	test_must_be_empty "$name"/err
+}
+
+check_sub_test_lib_test_err () {
+	name="$1" # stdin is the expected output from the test
+	_check_sub_test_lib_test_common "$name" &&
+	# expected error output is in descriptor 3
+	sed -e 's/^> //' -e 's/Z$//' <&3 >"$name"/expect.err &&
+	test_cmp "$name"/expect.err "$name"/err
+}