tinche/incant

incant's Issues

How to integrate a notion of scopes

I'm looking at this project and I like the relative simplicity of it compared to a lot of DI libs for python. But I'm wracking my head trying to figure out how I'd introduce dependency scope. That is...caching what was returned for a factory through multiple invocations on the same incantor object.

To me, this would be necessary to use incantor to inject longer-lived things like a database connection or a requests session or something like that.

Any plans or ideas on this? I'd be interested in helping if I could get an angle on how this might work.

UnboundLocalError when reusing dependencies

Incant fails when the invoked function uses a dependency, that is already used by another dependency:

import incant

incanter = incant.Incanter()


@incanter.register_by_name
def x() -> int:
    return 1


@incanter.register_by_name
def y(x: int) -> int:
    return x + 1


def func(x: int, y: int) -> None:
    assert x + 1 == y


incanter.invoke(func)

Traceback (most recent call last):
  File "/home/stefan/.../lib/tasks.py", line 28, in <module>
    incanter.invoke(func)
  File "/home/stefan/emsconda/lib/python3.10/site-packages/incant/__init__.py", line 112, in invoke
    return self.prepare(fn, is_async=False)(*args, **kwargs)
  File "<incant generated invoke of func>", line 2, in invoke_func
UnboundLocalError: local variable '_incant_local_1' referenced before assignment

It does not matter whether I use register_by_name or register_by_type.

Python is 3.10, incant is 22.1.0.