python-injector / python-injector/injector
Mypy error when getting abstract classes
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 1.5k
- Forks
- 94
- PR merge metrics
- No merged PRs in 30d
Description
Using Injector to bind a concrete class to an abstract interface, and then getting an instance of that interface causes a mypy error:
class MyABC(ABC): pass
class MyClass(MyABC): pass
injector = Injector()
injector.binder.bind(MyABC, to=MyClass) # error: Only concrete class can be given where "Type[MyABC]" is expected
injector.get(MyABC) # error: Only concrete class can be given where "Type[MyABC]" is expected
I hope that this can be resolved by fixing type hints (although it's certainly possible to configure Injector so that the type hints will be incorrect).
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the mypy errors in the examples using binder.bind and injector.get, then inspect the type hints for those entry points. The work is done when the abstract-interface binding and retrieval examples type-check without errors while preserving the intended Injector API.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- developer-experience
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100