Allow keyword errors for UTF-8 decoders

stdlib/@tests/test_cases/check_codecs.py

@@ -7,6 +7,8 @@
 assert_type(codecs.decode(b"x", "unicode-escape"), str)
 
 assert_type(codecs.decode(b"x", "utf-8"), str)
+assert_type(codecs.lookup("UTF-8").decode(b"potato", errors="replace"), tuple[str, int])
+codecs.lookup("ascii").decode(b"potato", errors="replace")  # type: ignore
 codecs.decode("x", "utf-8")  # type: ignore
 
 assert_type(codecs.decode("ab", "hex"), bytes)

stdlib/_codecs.pyi

@@ -70,7 +70,13 @@ def decode(obj: str, encoding: Literal["hex", "hex_codec"], errors: str = "stric
 @overload
 def decode(obj: ReadableBuffer, encoding: str = "utf-8", errors: str = "strict") -> str: ...
 
+_UTF8Encoding: TypeAlias = Literal["UTF-8", "utf-8", "UTF_8", "utf_8", "UTF8", "utf8"]
+
+@overload
+def lookup(encoding: _UTF8Encoding, /) -> codecs._UTF8CodecInfo: ...
+@overload
 def lookup(encoding: str, /) -> codecs.CodecInfo: ...
+
 def charmap_build(map: str, /) -> dict[int, int] | _EncodingMap: ...
 def ascii_decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
 def ascii_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...

stdlib/codecs.pyi

@@ -182,6 +182,15 @@ else:
             _is_text_encoding: bool | None = None,
         ) -> Self: ...
 
+@type_check_only
+class _UTF8Decoder(Protocol):
+    def __call__(self, input: ReadableBuffer, /, errors: str = ...) -> tuple[str, int]: ...
+
+@type_check_only
+class _UTF8CodecInfo(CodecInfo):
+    @property
+    def decode(self) -> _UTF8Decoder: ...
+
 def getencoder(encoding: str) -> _Encoder: ...
 def getdecoder(encoding: str) -> _Decoder: ...
 def getincrementalencoder(encoding: str) -> _IncrementalEncoder: ...