[code-reusability] Reuse positive integer helper

scripts/nvx_tools/benchmark.py

@@ -510,10 +510,7 @@ def configure_parser(
 
 
 def positive_int(value: str) -> int:
-    parsed = int(value)
-    if parsed < 1:
-        raise argparse.ArgumentTypeError("must be at least 1")
-    return parsed
+    return common.positive_int(value, message="must be at least 1")
 
 
 def apply_benchmark_suite_defaults(args: argparse.Namespace) -> None:

scripts/nvx_tools/common.py

@@ -39,10 +39,10 @@ def strict_json_object(pairs: list[tuple[str, object]]) -> dict[str, object]:
     return result
 
 
-def positive_int(value: str) -> int:
+def positive_int(value: str, *, message: str = "must be greater than zero") -> int:
     parsed = int(value)
     if parsed <= 0:
-        raise argparse.ArgumentTypeError("must be greater than zero")
+        raise argparse.ArgumentTypeError(message)
     return parsed
 
 

scripts/test_nvx_tools.py

@@ -508,6 +508,21 @@ def test_benchmark_preserves_canonical_shell_memory_defaults(self):
 
         self.assertEqual(args.shell_memories, [128, 256, 512])
 
+    def test_benchmark_positive_integer_diagnostics_are_stable(self):
+        for value, message in (
+            ("not-an-int", "argument --runs: invalid positive_int value: 'not-an-int'"),
+            ("0", "argument --runs: must be at least 1"),
+        ):
+            with self.subTest(value=value):
+                with (
+                    patch("sys.stderr", new_callable=io.StringIO) as errors,
+                    self.assertRaises(SystemExit) as exit_context,
+                ):
+                    nvx.parse_args(["benchmark", "--runs", value])
+
+                self.assertEqual(exit_context.exception.code, 2)
+                self.assertIn(message, errors.getvalue())
+
     def test_release_commands_keep_their_cli_contract(self):
         download = nvx.parse_args(
             ["download", "--repository", "example/nvx", "--hypervisor", "auto"]
@@ -11858,6 +11873,10 @@ def test_rejects_non_integer_input(self):
         with self.assertRaises(ValueError):
             common.positive_int("not-an-int")
 
+    def test_accepts_custom_error_message(self):
+        with self.assertRaisesRegex(argparse.ArgumentTypeError, "^must be at least 1$"):
+            common.positive_int("0", message="must be at least 1")
+
 
 class PositiveFloatTests(unittest.TestCase):
     def test_accepts_positive_finite_float(self):