NoReturn on contravariant generic #11508Description
from typing import Generic, Mapping, NoReturn, Sequence, TypeVar
T = TypeVar("T", contravariant=True)
class Foo(Generic[T]):
...
foo = Foo[int]()
bar = Foo[str]()
a1: Sequence[Foo[NoReturn]] = [foo] # no error
a2: Sequence[Foo[NoReturn]] = [bar] # no error
# error (this one seemed to be fixed around commit 32448b88370f8327c390f4e21666065c87ca95e2, then broken again)
a3: Sequence[Foo[NoReturn]] = [foo, bar]
a4: Sequence[Foo[NoReturn]] = [foo] or [bar] # error
a5: Mapping[str, Sequence[Foo[NoReturn]]] = { # error
"foo": [foo],
"bar": [], # error goes away if you change this to [foo]
}
a6: Sequence[Sequence[Foo[NoReturn]]] = [[foo], []] # errorhttps://mypy-play.net/?mypy=latest&python=3.10&gist=175deca029e02ea95af74f7c4a02856c