option to report possibly/conditionally uninitialized instance variables

[DetachHead]

looks like this only works on top-level statements:

class C:
    x: int # error

    def __init__(self) -> None:
        if bool():
            self.reset()
        else:
            self.reset()

though this may be difficult to correctly fix. for example if we were to copy the current behavior pyright uses to check for assignments in __init__ it would also be incorrect:

class C:
    x: int # no error, even though x is never assigned

    def __init__(self) -> None:
        if bool():
            self.x = 3

i think we would need to analyze the flow to address this properly. i havent yet touched that part of the pyright codebase so i have no idea what the best way to do this would be, so maybe we can just keep the behavior you have for now and create a follow-up issue for this.

Originally posted by @DetachHead in #975 (comment)