shared/options: add helper function to count positional args

src/shared/options.c

@@ -240,7 +240,7 @@ int option_parse(
         return option->id;
 }
 
-char** option_parser_get_args(OptionParser *state, int argc, char *argv[]) {
+char** option_parser_get_args(const OptionParser *state, int argc, char *argv[]) {
         /* Returns positional args as a strv.
          * If "--" was found, it has been removed. */
 

src/shared/options.h

@@ -2,6 +2,7 @@
 #pragma once
 
 #include "shared-forward.h"
+#include "strv.h"
 
 typedef enum OptionFlags {
         OPTION_OPTIONAL_ARG  = 1U << 0,  /* Same as optional_argument in getopt */
@@ -89,7 +90,11 @@ int option_parse(
 #define FOREACH_OPTION(parser, opt, argc, argv, ret_a, on_error) \
         FOREACH_OPTION_FULL(parser, opt, argc, argv, /* ret_o= */ NULL, ret_a, on_error)
 
-char** option_parser_get_args(OptionParser *state, int argc, char *argv[]);
+char** option_parser_get_args(const OptionParser *state, int argc, char *argv[]);
+static inline size_t option_parser_get_n_args(const OptionParser *state, int argc, char *argv[]) {
+        return strv_length(option_parser_get_args(state, argc, argv));
+}
+
 int _option_parser_get_help_table(
                 const Option options[],
                 const Option options_end[],

src/test/test-options.c

@@ -57,6 +57,8 @@ static void test_option_parse_one(
         char **args = option_parser_get_args(&state, argc, argv);
         ASSERT_TRUE(strv_equal(args, remaining));
         ASSERT_STREQ(argv[0], saved_argv0);
+
+        ASSERT_EQ(option_parser_get_n_args(&state, argc, argv), strv_length(remaining));
 }
 
 static void test_option_invalid_one(