Typing spec update: `ClassVar` and `Final` within `TypedDict`

[InSyncWithFoo]

• PR: #1890: Specs clarification: Forbid ClassVar and Final within TypedDict body
• Discussion: What does it mean for a TypedDict to have a ClassVar field?

As discussed in the thread linked above, major type checkers currently don't consider such a ClassVar an error.

As for Final, Pyright and Mypy do reports it, but their messages are unclear; Pytype and Pyre, on the other hand, ignores such items completely:

(playgrounds: Pyright, Mypy, Pyre)

class TD(TypedDict):
    v: ClassVar[int]     # all     => fine

    f: Final[int]        # pyright => error: "f" is declared Final, but value is not assigned
                         # mypy    => error: Final can be only used as an outermost qualifier in a variable annotation
                         # pyre    => fine
                         # pytype  => fine

    a: Final[int] = 42   # pyright => error: TypedDict classes can contain only type annotations
                         # mypy    => error: Right hand side values are not supported in TypedDict
                         # pyre    => fine
                         # pytype  => fine

Reference implementation: None.

TC Sign-off

• Carl
• Eric
• Jelle
• Jukka
• Rebecca

[InSyncWithFoo]

I'm closing this as the PR has been merged.