submodule update: add tests for --filter

Test the "--filter" option to make sure we don't break anything while
refactoring "git submodule update".

Signed-off-by: Glen Choo <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: chooglen

t/t7406-submodule-update.sh

@@ -1071,4 +1071,16 @@ test_expect_success 'submodule update --quiet passes quietness to fetch with a s
 	)
 '
 
+test_expect_success 'submodule update --filter requires --init' '
+	test_expect_code 129 git -C super submodule update --filter blob:none
+'
+
+test_expect_success 'submodule update --filter sets partial clone settings' '
+	test_when_finished "rm -rf super-filter" &&
+	git clone cloned super-filter &&
+	git -C super-filter submodule update --init --filter blob:none &&
+	test_cmp_config -C super-filter/submodule true remote.origin.promisor &&
+	test_cmp_config -C super-filter/submodule blob:none remote.origin.partialclonefilter
+'
+
 test_done