NotRequired receives (T,) instead of T in Generic TypedDict

[NCPlayz]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

Pydantic seems to resolve the Generic in a TypedDict as a tuple value for NotRequired and Required, which only accepts single types. (str,) should become str.

Traceback (most recent call last):
  File "test.py", line 18, in <module>
    FooWithStrAdapter = TypeAdapter(FooWithStr)
... # truncated error
  File "env/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 830, in _match_generic_type
    return self._typed_dict_schema(obj, origin)
  File "env/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1097, in _typed_dict_schema
    annotation = replace_types(annotation, typevars_map)
  File "env/lib/python3.10/site-packages/pydantic/_internal/_generics.py", line 314, in replace_types
    return origin_type[resolved_type_args]
  File "/opt/conda/envs/py310/lib/python3.10/typing.py", line 312, in inner
    return func(*args, **kwds)
  File "/opt/conda/envs/py310/lib/python3.10/typing.py", line 403, in __getitem__
    return self._getitem(self, parameters)
  File "env/lib/python3.10/site-packages/typing_extensions.py", line 1884, in NotRequired
    item = typing._type_check(parameters, f'{self._name} accepts only a single type.')
  File "/opt/conda/envs/py310/lib/python3.10/typing.py", line 176, in _type_check
    raise TypeError(f"{msg} Got {arg!r:.100}.")
TypeError: NotRequired accepts only a single type. Got (<class 'str'>,).

Example Code

from typing_extensions import TypedDict, TypeVar, NotRequired, Generic
from pydantic import TypeAdapter

T = TypeVar("T")


class FooStr(TypedDict):
    type: NotRequired[str]


class FooGeneric(TypedDict, Generic[T]):
    type: NotRequired[T]


FooWithStr = FooGeneric[str]

FooStrAdapter = TypeAdapter(FooStr) # passes
FooWithStrAdapter = TypeAdapter(FooWithStr) # fails

Python, Pydantic & OS Version

pydantic version: 2.4.2
        pydantic-core version: 2.10.1
          pydantic-core build: profile=release pgo=true
                 install path: env/lib/python3.10/site-packages/pydantic
               python version: 3.10.5 | packaged by conda-forge | (main, Jun 14 2022, 07:06:46) [GCC 10.3.0]
                     platform: Linux
             related packages: typing_extensions-4.8.0 fastapi-0.104.0

[sydney-runkle]

Hi @NCPlayz,

Thanks for reporting this. This does look like a bug. I'll have a fix up shortly 🐛 🔨 !

[sydney-runkle]

@NCPlayz,

I just merged the fix - this fix should be active in the next release :).