Address reviews

Author: ubaskota

packages/aws-sdk-signers/.changes/next-release/aws-sdk-signers-breaking-9b52e1c29eb541999e2239be4c725d00.json

@@ -1,4 +1,4 @@
 {
   "type": "breaking",
-  "description": "Replace FieldPosition enum with a Literal type"
+  "description": "Replace `FieldPosition` enum values with string literals for `Field.kind`. Use \"header\" and \"trailer\" instead of `FieldPosition.HEADER` and `FieldPosition.TRAILER`."
 }

packages/aws-sdk-signers/src/aws_sdk_signers/_http.py

@@ -15,11 +15,13 @@
 from copy import deepcopy
 from dataclasses import dataclass
 from functools import cached_property
-from typing import TypedDict
+from typing import TypedDict, get_args
 from urllib.parse import urlunparse
 
 import aws_sdk_signers.interfaces.http as interfaces_http
 
+_VALID_FIELD_POSITIONS = frozenset(get_args(interfaces_http.FieldPosition))
+
 
 class Field(interfaces_http.Field):
     """A name-value pair representing a single field in an HTTP Request or Response.
@@ -40,6 +42,8 @@ def __init__(
     ):
         self.name = name
         self.values: list[str] = list(values) if values is not None else []
+        if kind not in _VALID_FIELD_POSITIONS:
+            raise ValueError(f"Unknown field kind: {kind!r}")
         self.kind = kind
 
     def add(self, value: str) -> None:

packages/aws-sdk-signers/tests/unit/test_fields.py

@@ -313,3 +313,8 @@ def test_fields_delitem_missing() -> None:
     fields = Fields([Field(name="fname1")])
     with pytest.raises(KeyError):
         del fields["fname2"]
+
+
+def test_field_invalid_kind() -> None:
+    with pytest.raises(ValueError, match="Unknown field kind"):
+        Field(name="fname", kind="metadata")  # type: ignore

packages/smithy-http/.changes/next-release/smithy-http-breaking-f567cc46e12d4f61ac5f85b65a0e4426.json

@@ -1,4 +1,4 @@
 {
   "type": "breaking",
-  "description": "Replace FieldPosition enum with a Literal type"
+  "description": "Replace `FieldPosition` enum values with string literals for `Field.kind`. Use \"header\" and \"trailer\" instead of `FieldPosition.HEADER` and `FieldPosition.TRAILER`."
 }

packages/smithy-http/src/smithy_http/__init__.py

@@ -2,12 +2,15 @@
 # SPDX-License-Identifier: Apache-2.0
 from collections import Counter, OrderedDict
 from collections.abc import Iterable, Iterator
+from typing import get_args
 
 from . import interfaces
 from .interfaces import FieldPosition
 
 __version__ = "0.3.1"
 
+_VALID_FIELD_POSITIONS = frozenset(get_args(FieldPosition))
+
 
 class Field(interfaces.Field):
     """A name-value pair representing a single field in an HTTP Request or Response.
@@ -28,6 +31,8 @@ def __init__(
     ):
         self.name = name
         self.values: list[str] = list(values) if values is not None else []
+        if kind not in _VALID_FIELD_POSITIONS:
+            raise ValueError(f"Unknown field kind: {kind!r}")
         self.kind = kind
 
     def add(self, value: str) -> None:

packages/smithy-http/tests/unit/test_fields.py

@@ -316,3 +316,8 @@ def test_fields_delitem_missing() -> None:
     fields = Fields([Field(name="fname1")])
     with pytest.raises(KeyError):
         del fields["fname2"]
+
+
+def test_field_invalid_kind() -> None:
+    with pytest.raises(ValueError, match="Unknown field kind"):
+        Field(name="fname", kind="metadata")  # type: ignore