Incorrect typing for register_structure_hook() and register_unstructure_hook()

[JimDabell]

• cattrs version: 24.1.1
• Python version: 3.12.6
• Operating System: macOS Sequoia 15.0 (24A335)

Description

Custom (un)structuring hooks appear to have incorrect typing information. cattrs v24.1.1 already seems to have fixed this for the factory variant, as described in #578 and #579, but the individual hooks still seem to be incorrect.

What I Did

The following sample code is provided by the documentation :

@converter.register_structure_hook
def my_int_hook(val: Any, _) -> int:
    """This hook will be registered for `int`s."""
    return int(val)

This causes the following type warning (using Pylance in VS Code):

No overloads for "register_structure_hook" match the provided arguments
  Argument types: ((val: Any, _: Unknown) -> int)

[Tinche]

Bleh, guess I need to do another pass on this.

Wish there was a good way to test types; I've used the pytest-mypy-plugins package on a branch but wasn't super happy with it.

[Tinche]

Alright, think I got this fixed. Thanks!

[JimDabell]

Just confirming that’s fixed for me. Thanks!