From 4d21d5a87d5e9dad17500078ea251db0cd7e941c Mon Sep 17 00:00:00 2001
From: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Date: Thu, 3 Feb 2022 14:20:11 -0800
Subject: [PATCH] codecs: allow str to bytes decoding for "hex", fix overloads
 (#7118)

Fixes #7115

Co-authored-by: hauntsaninja <>
---
 stdlib/codecs.pyi | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/stdlib/codecs.pyi b/stdlib/codecs.pyi
index aa5756fec..a9fa9c5d0 100644
--- a/stdlib/codecs.pyi
+++ b/stdlib/codecs.pyi
@@ -35,8 +35,8 @@ class _IncrementalDecoder(Protocol):
     def __call__(self, errors: str = ...) -> IncrementalDecoder: ...
 
 # The type ignore on `encode` and `decode` is to avoid issues with overlapping overloads, for more details, see #300
-# mypy and pytype disagree about where the type ignore can and cannot go, so alias the long type
-_BytesToBytesEncodingT = Literal[
+# https://docs.python.org/3/library/codecs.html#binary-transforms
+_BytesToBytesEncoding = Literal[
     "base64",
     "base_64",
     "base64_codec",
@@ -54,17 +54,23 @@ _BytesToBytesEncodingT = Literal[
     "zlib",
     "zlib_codec",
 ]
+# https://docs.python.org/3/library/codecs.html#text-transforms
+_StrToStrEncoding = Literal["rot13", "rot_13"]
 
 @overload
-def encode(obj: bytes, encoding: _BytesToBytesEncodingT, errors: str = ...) -> bytes: ...
+def encode(obj: bytes, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...
 @overload
-def encode(obj: str, encoding: Literal["rot13", "rot_13", "hex"] = ..., errors: str = ...) -> str: ...  # type: ignore[misc]
+def encode(obj: str, encoding: _StrToStrEncoding, errors: str = ...) -> str: ...  # type: ignore[misc]
 @overload
 def encode(obj: str, encoding: str = ..., errors: str = ...) -> bytes: ...
 @overload
-def decode(obj: bytes, encoding: _BytesToBytesEncodingT, errors: str = ...) -> bytes: ...  # type: ignore[misc]
+def decode(obj: bytes, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...  # type: ignore[misc]
 @overload
-def decode(obj: str, encoding: Literal["rot13", "rot_13", "hex"] = ..., errors: str = ...) -> str: ...
+def decode(obj: str, encoding: _StrToStrEncoding, errors: str = ...) -> str: ...
+
+# hex is officially documented as a bytes to bytes encoding, but it appears to also work with str
+@overload
+def decode(obj: str, encoding: Literal["hex", "hex_codec"], errors: str = ...) -> bytes: ...
 @overload
 def decode(obj: bytes, encoding: str = ..., errors: str = ...) -> str: ...
 def lookup(__encoding: str) -> CodecInfo: ...