Merging two TypedDict into one dict[K, V]

[moosbruggerj]

Hi,
I currently have a piece of code, that receives two incompatible typed dicts, and I need to pass them as one merged dictionary along.
Preferably, I would like to use the | operator to merge the two dictionaries, however, this raises type errors in both mypy and pyright.

If I use unpacking, both type checkers accept the code.

from typing import TypedDict
from typing_extensions import reveal_type

class A(TypedDict):
    x: str
    z: str

class B(TypedDict):
    x: str
    y: str

a: A = {'x': 'a', 'z': 'a'}
b: B = {'x': 'b', 'y': 'b'}
c = a | b  # <-- error: Operator "|" not supported for types "A" and "B"
reveal_type(c)  # pyright: unknown, mypy:  TypedDict('typed_dict_merge.A', {'x': builtins.str, 'z': builtins.str})
d = {**a, **b}
reveal_type(d)  # pyright: dict[str, str], mypy: builtins.dict[builtins.str, builtins.object]
print(c == d)  # prints True at runtime

Is there a way to annotate the code in a way to use the | operator? Preferably without using cast.
Explicitly annotating c does not seem to work:

c: dict[str, str] = a | b  # error still persists

Creating a compatible TypedDict seems not to be a solution either. It only works with unpacking and pyright:

class C(A, B, TypedDict):
    pass

c: C = a | b  # same as before
e: C = {'x': 'b', 'z': 'a', 'y': 'b'}  # ok
d: C = {**a, **b}  # ok in pyright, error in mypy: Expected TypedDict key to be string literal
reveal_type(d)  # revealed as C

Context
This piece of code comes from a django webserver and the two TypedDicts passed into this method contain data from different sources. The merged dictionary is passed along to django factory methods. This makes exact type information (TypedDicts) nice, but not necessary. However, the codebase uses the | operator to merge dicts a lot. Using unpacking here would stand out.

Version
python: Python 3.10.8
pyright: pyright 1.1.276
mypy: mypy 0.961 (compiled: yes)

[Gobot1234]

I think the ideal solution here is just to wait for Intersection to be finished (see #213)