from __future__ import annotations

from typing import Callable

from mypy.plugin import FunctionContext, Plugin

from mypy.types import CallableType, Type, get_proper_type

class MyPlugin(Plugin):

def get_function_hook(self, fullname: str) -> Callable[[FunctionContext], Type] | None:

if fullname == "m.decorator1":

return decorator_call_hook

if fullname == "m._decorated": # This is a dummy name generated by the plugin

return decorate_hook

return None

def decorator_call_hook(ctx: FunctionContext) -> Type:

default = get_proper_type(ctx.default_return_type)

if isinstance(default, CallableType):

return default.copy_modified(name="m._decorated")

return ctx.default_return_type

def decorate_hook(ctx: FunctionContext) -> Type:

default = get_proper_type(ctx.default_return_type)

if isinstance(default, CallableType):

return default.copy_modified(ret_type=ctx.api.named_generic_type("builtins.str", []))

return ctx.default_return_type

def plugin(version: str) -> type[MyPlugin]:

return MyPlugin