Summary

On the following code, ty correctly reports that the argument to function f is incorrect (playground):

class A: pass
B = A
def f(b: B): pass
f("")  # Argument to function `f` is incorrect: Expected `A`, found `Literal[""]` (invalid-argument-type) [Ln 4, Col 3]

When the last two lines are moved into a separate file, and B is imported, ty no longer detects the error (playground):

from main import B
def f(b: B): pass
f("")

In the main file, the implicit type alias B is correctly inferred to be <class 'A'>. But when it's imported from another module, ty infers Unknown | <class 'A'>.

I'm not sure how broad the actual underlying issue is.

Version

No response