uuid4() - become unusuable for safe typing without casting or ignoring about faker

[stefan6419846]

Feel free to provide a corresponding PR which improves this.

[sshishov]

@stefan6419846 it will require breaking changes, is it okay? I definitely can provide PR for this one

[fcurella]

Can't this be fixed by using some kind of TypeVar in the type hint of uuid4?

[steve-mavens]

Based on the type in the docs:

def uuid4(cast_to: ~typing.Callable[[~uuid.UUID], str] | ~typing.Callable[[~uuid.UUID], bytes] | None = <class 'str'>) → bytes | str | UUID

Like fcurella says, I think it should be possible to overload it like:

T = TypeVar('T', str, bytes)

@overload
def uuid4() -> str: ...
@overload
def uuid4(cast_to: Callable[[UUID], T]) -> T: ...
@overload
def uuid4(cast_to: None) -> UUID: ...

Failing that, get rid of T by explicitly listing both possibilities:

@overload
def uuid4() -> str: ...
@overload
def uuid4(cast_to: Callable[[UUID], str]) -> str: ...
@overload
def uuid4(cast_to: Callable[[UUID], bytes]) -> bytes: ...
@overload
def uuid4(cast_to: None) -> UUID: ...

I don't think that should be a breaking change.

Or potentially you could make the function more general, allowing cast_to to convert to any type at all instead of just str or bytes:

T = TypeVar('T')

@overload
def uuid4() -> str: ...
@overload
def uuid4(cast_to: Callable[[UUID], T]) -> T: ...
@overload
def uuid4(cast_to: None) -> UUID: ...