Enum Literal Handling Regression

[max-muoto]

To preface, apologies if there's a simpler reproducible example here, mostly trying to replicate what's happening across modules in my codebase. In Pyright 1.1.362, something like this would have been fine:

import enum
from typing import TypeAlias

class MyEnum(enum.StrEnum):
    ARG_1 = "ARG_1"
    ARG_2 = "ARG_1"
    

MyEnumAlias: TypeAlias = MyEnum

def get_enum() -> MyEnumAlias: ...

z = get_enum()

def foo(enum: MyEnum): ...

foo(z.ARG_1)

That being, we alias an enum, and pass in value off the aliased type, now in 1.1.362, you'll get a warning when trying to pass in ARG_1:

In this example, it's obviously pointless to alias, in reality, we have an enum setting that's we're aliasing to change the typing of, think, MY_ENUM as MyEnum, for a wrapper we have on some project settings.

Pyright Playground

Version: 1.1.363

[erictraut]

I agree this is a bug, but I think the code sample is suspect and arguably should be considered a bug. Accessing enum members from an instance of an enum happens to work with Python's enum class, but it's probably not intended.

Consider the following. Does this really make sense?

print(MyEnum.ARG_1.ARG_2.ARG_1.ARG_2.ARG_1)

Perhaps your code sample intends to return type[MyEnumAlias] from get_enum?

I'll update pyright to match the runtime behavior even though I think it doesn't make much sense in this case.

[max-muoto]

I agree this is a bug, but I think the code sample is suspect and arguably should be considered a bug. Accessing enum members from an instance of an enum happens to work with Python's enum class, but it's probably not intended.

Consider the following. Does this really make sense?

print(MyEnum.ARG_1.ARG_2.ARG_1.ARG_2.ARG_1)

Perhaps your code sample intends to return type[MyEnumAlias] from get_enum?

I'll update pyright to match the runtime behavior even though I think it doesn't make much sense in this case.

You're right! My code did mean to do that, unfortunately we're accessing some configuration settings through Django typed as Any, so didn't catch this. Thanks.

[erictraut]

This is addressed in pyright 1.1.364.