Consider unsafely assuming in narrowing that multiple inheritance won't happen #1578
Description
Summary
Is it possible for Ty to infer the type of the Iterator Variable when Iterator is properly defined?
In the below example running, area is properly defined above
if allowed:
area: list[Area] = await user.get_allowed_areas()
else:
area: Area = await user.area_get()
but when I run ty check, I get the following
error[unresolved-attribute]: Object of type `object` has no attribute `get_model`
--> app/routers/me.py:113:36
|
112 | if isinstance(area, list):
113 | models: list[AreaModel] = [await a.get_model() for a in area]
| ^^^^^^^^^^^
114 | return JSONResponse(content=loads(dumps([a.content() for a in models])), status_code=200)
|
info: rule `unresolved-attribute` is enabled by default
I was able to resolve it by adding a: Area above line 113, but that causes ruff to throw warning Local variable 'a' is annotated but never used
One thing, I am not sure if this could be impacting it, but the variable area can actually be of type Area or type list[Area], hence the if isinstance(area, list): at line 112.
Version
ty 0.0.1-alpha.26 (b225fd8 2025-11-10)