Expected TypedDict key to be string literal for Union of TypedDict and dict

[AllexVeldman]

I'm getting error: Expected TypedDict key to be string literal [misc] from mypy for the following:

from typing import TypedDict

class Foo(TypedDict):
    some: str
    name: str

type Bar = dict[int, float]

type Baz = Foo | Bar

baz: Baz = {"some": "foo", "name": "x"}  # OK
bar: Bar = {1: 5.2, 2: 7.4}  # OK

baz2: Baz = {1: 5.2} # error: Expected TypedDict key to be string literal  [misc]

I would expect baz2 to be valid, or am I missing something?

It seems mypy does try to resolve to the dict[int, float]:

baz3: Baz = {"1": 5.2} # error: Dict entry 0 has incompatible type "str": "float"; expected "int": "float"  [dict-item]

[JelleZijlstra]

Yes, that seems like a bug in mypy. Zuban and ty have the same bug.

[AllexVeldman]

Should I open an Issue for mypy or do you already know of one?

[JelleZijlstra]

I don't recall an issue; I'd search for some terms like "union" "TypedDict" in the issue tracker first.

[AllexVeldman]

python/mypy#21510

[JelleZijlstra]

I also reported astral-sh/ty#3488 (apparently discussions don't get automatic backlinks?).