Use shared field guards for TransformConfig numeric settings

src/hflow/transform.py

@@ -56,14 +56,18 @@
 import hashlib
 import json
 import logging
-import math
 from collections.abc import Callable, Mapping, Sequence
 from copy import copy
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any, Literal
 
 from hflow import video as video_module
+from hflow._field_guards import (
+    require_int_in_range,
+    require_positive_float,
+    require_positive_int,
+)
 from hflow._grouped_mcap_writer import (
     NO_SCHEMA_ID,
     ChannelId,
@@ -156,28 +160,11 @@ class TransformConfig:
 
     def __post_init__(self) -> None:
         """Reject invalid settings before they become a pipeline identity."""
-        if isinstance(self.crf, bool) or not isinstance(self.crf, int):
-            raise ValueError(f"crf must be an int, got {type(self.crf).__name__}")
-        if not 0 <= self.crf <= 51:
-            raise ValueError(f"crf must be between 0 and 51, got {self.crf}")
-
+        require_int_in_range(self.crf, "crf", minimum=0, maximum=51)
         if self.gop_seconds is not None:
-            if isinstance(self.gop_seconds, bool) or not isinstance(self.gop_seconds, int | float):
-                raise ValueError(
-                    f"gop_seconds must be an int or float, got {type(self.gop_seconds).__name__}"
-                )
-            if not math.isfinite(self.gop_seconds) or self.gop_seconds <= 0:
-                raise ValueError(f"gop_seconds must be positive and finite, got {self.gop_seconds}")
-
+            require_positive_float(self.gop_seconds, "gop_seconds")
         if self.chunk_size_bytes is not None:
-            if isinstance(self.chunk_size_bytes, bool) or not isinstance(
-                self.chunk_size_bytes, int
-            ):
-                raise ValueError(
-                    f"chunk_size_bytes must be an int, got {type(self.chunk_size_bytes).__name__}"
-                )
-            if self.chunk_size_bytes <= 0:
-                raise ValueError(f"chunk_size_bytes must be positive, got {self.chunk_size_bytes}")
+            require_positive_int(self.chunk_size_bytes, "chunk_size_bytes")
 
 
 @dataclass(frozen=True)

tests/test_transform.py

@@ -49,24 +49,27 @@ def test_pipeline_version_is_a_content_hash() -> None:
 
 
 @pytest.mark.parametrize(
-    ("construct", "field"),
+    ("construct", "message"),
     [
-        (lambda: TransformConfig(crf=True), "crf"),
-        (lambda: TransformConfig(crf=-1), "crf"),
-        (lambda: TransformConfig(crf=52), "crf"),
-        (lambda: TransformConfig(gop_seconds=True), "gop_seconds"),
-        (lambda: TransformConfig(gop_seconds=0), "gop_seconds"),
-        (lambda: TransformConfig(gop_seconds=float("nan")), "gop_seconds"),
-        (lambda: TransformConfig(gop_seconds=float("inf")), "gop_seconds"),
-        (lambda: TransformConfig(chunk_size_bytes=True), "chunk_size_bytes"),
-        (lambda: TransformConfig(chunk_size_bytes=0), "chunk_size_bytes"),
-        (lambda: TransformConfig(chunk_size_bytes=-1), "chunk_size_bytes"),
+        (lambda: TransformConfig(crf=True), "crf must be an int, got bool"),
+        (lambda: TransformConfig(crf=-1), "crf must be in [0, 51], got -1"),
+        (lambda: TransformConfig(crf=52), "crf must be in [0, 51], got 52"),
+        (lambda: TransformConfig(gop_seconds=True), "gop_seconds must be an int or float, got bool"),
+        (lambda: TransformConfig(gop_seconds=0), "gop_seconds must be > 0, got 0"),
+        (lambda: TransformConfig(gop_seconds=float("nan")), "gop_seconds must be finite, got nan"),
+        (lambda: TransformConfig(gop_seconds=float("inf")), "gop_seconds must be finite, got inf"),
+        (
+            lambda: TransformConfig(chunk_size_bytes=True),
+            "chunk_size_bytes must be an int, got bool",
+        ),
+        (lambda: TransformConfig(chunk_size_bytes=0), "chunk_size_bytes must be > 0, got 0"),
+        (lambda: TransformConfig(chunk_size_bytes=-1), "chunk_size_bytes must be > 0, got -1"),
     ],
 )
 def test_transform_config_rejects_invalid_numeric_settings(
-    construct: Callable[[], TransformConfig], field: str
+    construct: Callable[[], TransformConfig], message: str
 ) -> None:
-    with pytest.raises(ValueError, match=field):
+    with pytest.raises(ValueError, match=f"^{message}$"):
         construct()