Anders Kaseorg ca1d9603cb decorator: Fix type of signature-changing decorators. ...

In a decorator annotated with generic type (ViewFuncT) -> ViewFuncT,
the type variable ViewFuncT = TypeVar(…) must be instantiated to
the *same* type in both places.  This amounts to a claim that the
decorator preserves the signature of the view function, which is not
the case for decorators that add a user_profile parameter.

The corrected annotations enforce no particular relationship between
the input and output signatures, which is not the ideal type we might
get if mypy supported variadic generics, but is better than enforcing
a relationship that is guaranteed to be wrong.

This removes a bunch of ‘# type: ignore[call-arg] # mypy doesn't seem
to apply the decorator’ annotations.  Mypy does apply the decorator,
but the decorator’s incorrect annotation as signature-preserving made
it appear as if it didn’t.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

2020-06-23 11:29:54 -07:00

7.5 KiB

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