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Factory for TypeVar type can't be used for a specific type #527
Description
If we try to use a factory for TypeVar type T without a wrapper Something[T] we will get dishka.exceptions.NoFactoryError. Slightly modified example from the documentation shows the problem:
from typing import TypeVar
from dishka import make_container, Provider, provide, Scope
T = TypeVar("T", bound=int)
class MyProvider(Provider):
@provide(scope=Scope.APP)
def make_a(self, t: type[T]) -> T:
print("Requested type", t)
return 42
container = make_container(MyProvider())
container.get(int)Traceback (most recent call last):
File "xxx/test.py", line 16, in <module>
container.get(int)
File "xxx/python3.12/site-packages/dishka/container.py", line 164, in get
return self._get_unlocked(key)
^^^^^^^^^^^^^^^^^^^^^^^
File "xxx/python3.12/site-packages/dishka/container.py", line 195, in _get_unlocked
return self.parent_container._get(key) # noqa: SLF001
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "xxx/python3.12/site-packages/dishka/container.py", line 174, in _get
return self._get_unlocked(key)
^^^^^^^^^^^^^^^^^^^^^^^
File "xxx/python3.12/site-packages/dishka/container.py", line 189, in _get_unlocked
raise NoFactoryError(
dishka.exceptions.NoFactoryError: Cannot find factory for (int, component='', scope=Scope.APP). Check scopes in your providers. It is missing or has invalid scope.
Process finished with exit code 1
I expected to get 42.
Activity
Tishka17 commentedon Aug 23, 2025
Looks like solving this can highly affect performance when accessing parent scopes. We need a faster way to distinguish objects with incorrect scope and absent ones
Tishka17 commentedon Sep 13, 2025
Probably related to implementation of #543