[PATCH v2 3/4] test-tool: migrate read-cache-again to parse_options()

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

Change the newly added (but then mostly copy/pasted) read-cache-perf
to use the parse_options() API. I have no plans to further modify
read-cache-again, but making these commands consistent has a value in
and of itself.

Since we check the "cnt = < 1" case now via more idiomatic
post-parse_options() assertions we can move from the for-loop to a
while-loop and ditch the "i" variable.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/helper/test-read-cache-again.c | 26 ++++++++++++++++++++------
 t/t7519-status-fsmonitor.sh      |  2 +-
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/t/helper/test-read-cache-again.c b/t/helper/test-read-cache-again.c
index 707db036cb1..fa456ca229e 100644
--- a/t/helper/test-read-cache-again.c
+++ b/t/helper/test-read-cache-again.c
@@ -1,20 +1,34 @@
 #include "test-tool.h"
 #include "cache.h"
+#include "parse-options.h"
+
+static const char *read_cache_again_usage[] = {
+	"test-tool read-cache-again [<options>...] <file>",
+	NULL
+};
 
 int cmd__read_cache_again(int argc, const char **argv)
 {
 	struct repository *r = the_repository;
-	int i, cnt;
+	int cnt = 2;
 	const char *name;
+	struct option options[] = {
+		OPT_INTEGER(0, "count", &cnt, "number of passes"),
+		OPT_END()
+	};
 
-	if (argc != 2)
-		die("usage: test-tool read-cache-again <count> <file>");
-
-	cnt = strtol(argv[0], NULL, 0);
+	argc = parse_options(argc, argv, "test-tools", options,
+			     read_cache_again_usage, 0);
+	if (argc != 1)
+		usage_msg_opt("Too many arguments.", read_cache_again_usage,
+			      options);
+	if (cnt < 1)
+		usage_msg_opt("Need at least one pass.", read_cache_again_usage,
+			      options);
 	name = argv[2];
 
 	setup_git_directory();
-	for (i = 0; i < cnt; i++) {
+	while (cnt--) {
 		int pos;
 		repo_read_index(r);
 		refresh_index(r->index, REFRESH_QUIET,
diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh
index 7de5fcb1bd7..817e642f58e 100755
--- a/t/t7519-status-fsmonitor.sh
+++ b/t/t7519-status-fsmonitor.sh
@@ -360,7 +360,7 @@ test_expect_success UNTRACKED_CACHE 'ignore .git changes when invalidating UNTR'
 test_expect_success 'discard_index() also discards fsmonitor info' '
 	test_config core.fsmonitor "$TEST_DIRECTORY/t7519/fsmonitor-all" &&
 	test_might_fail git update-index --refresh &&
-	test-tool read-cache-again 2 tracked >actual &&
+	test-tool read-cache-again --count=2 tracked >actual &&
 	printf "tracked is%s up to date\n" "" " not" >expect &&
 	test_cmp expect actual
 '
-- 
2.33.0.663.gbaff4edb973