dry-python / dry-python/returns

Incorrect result type for `returns.curry.partial` with keyword arguments for positional parameters

Ouverte
#2,191 1 commentaire 0 réactions 0 personnes assignées Voir sur GitHub
bug
Langage dominant
Python
Étoiles
4.4k
Forks
155
Merge moyen
2 h 27 min
PR mergées (30 j)
22

Description

# Bug report

## What's wrong

When using `returns.curry.partial`, if you partially apply a positional parameter using a keyword argument, the resulting type is incorrect. Result type of callable allows passing the remaining arguments as positional, but this leads to a runtime error.

### Example

```python
def foo(x: int, y: int) -> None:
...

bar = returns.curry.partial(foo, x=1)
reveal_type(bar)
# => Mypy: "def (y: builtins.int)"
# => Expected: "def (*, y: builtins.int)"

bar(2)
# No errors from mypy, but got runtime error
# TypeError: foo() got multiple values for argument 'x'
```

## How is that should be

In this scenario, the remaining parameters should be strictly keyword-only. The resulting type should reflect this restriction, and passing a positional argument should be flagged as an error at type checking time.

## System information

- `python` version: `3.13.4`
- `returns` version: `0.25.0`
- `mypy` version: `1.15.0`

Guide de contribution

Ouvrir le guide de contribution

Évaluation

Cette issue n'a pas encore été évaluée.

Recevez les nouvelles issues par e-mail

Un résumé court des issues GitHub adaptées aux débutants.