Allow to register new class/dataclass/attribute makers in attrs plugin

This is a feature request.

attrs is very much intended to be composable (e.g. https://github.com/hynek/environ_config) but currently the attrs plugin only works on the core library's functions: https://github.com/python/mypy/blob/b2d61741623f2a0573f2b1bdb8391ceed862cf69/mypy/plugins/attrs.py#L24-L37

I would like to be able to signal somehow to mypy, that some function is a wrapper around @attr.s/@attr.ib/@attr.dataclass. Not only would third-party applications benefit, but I could really use it while experimenting on https://github.com/python-attrs/attrs/issues/408.

Any ideas/plans how we could achieve that?

cc also @euresti & @chadrik

Inizia da mypy/plugins/attrs.py, in particolare dalle funzioni della libreria principale elencate intorno alle righe 24–37, e segui il modo in cui il plugin attrs riconosce @attr.s, @attr.ib e @attr.dataclass. Esamina la issue di attrs collegata per il caso d’uso motivante dei wrapper. Il lavoro è completato quando esiste un modo documentato e testato che consenta ai wrapper di terze parti di registrare un comportamento equivalente per classi, dataclass o creatori di attributi.