I have a class and a corresponding factory function that holds some state in a closure (event_bus):

from typing import TypeVar, Generic, Callable, Any

class EventBus:

    def subscribe(self):
        print("Subscribed")

    def publish(self):
        print("Published") 

T = TypeVar('T')

def create_property(event_bus: EventBus):
    class Property(Generic[T]):
        def __init__(self, validator: Callable[[T], bool]):
            self._validator = validator

        def __set_name__(self, obj: Any, name: str):
            self.name = name

        def __get__(self, obj: Any, type: Any) -> T:
            return obj.__dict__.get(self.name)

        def __set__(self, obj: Any, value: T):
            if not self._validator(value):
                raise ValueError("Invalid value")
            obj.__dict__[self.name] = value
            event_bus.publish()

    def property(validator: Callable[[T], bool] = lambda x: True) -> Property[T]:    
        return Property(validator)

    return property

Now this compiles, and the property function has the correct type: Callable[..., Property[T]]. Property can be used as a descriptor, but when I try to do so I get compiler errors:

property: Callable[..., Property[T]] = create_property(EventBus())   


class MyComponent:

    width = property() # Type of "width" is partially unknown
                       # Type of "width" is "Property[Unknown]
    height: int = property(lambda x: x > 0) # Expression of type "Property[Unknown]" is 
                                            # incompatible with declared type "int"

What am I doing wrong? How do I call the generic property function properly?