from mypy.types import LiteralType, AnyType, TypeOfAny, Type

from mypy.plugin import Plugin, MethodContext

from typing import Callable, Optional

# If radd exists, there shouldn't be an error. If it doesn't exist, then there will be an error

def type_add(ctx: MethodContext) -> Type:

ctx.api.fail("fail", ctx.context)

return AnyType(TypeOfAny.from_error)

def type_radd(ctx: MethodContext) -> Type:

return LiteralType(7, fallback=ctx.api.named_generic_type('builtins.int', []))

class TestPlugin(Plugin):

def get_method_hook(self, fullname: str) -> Optional[Callable[[MethodContext], Type]]:

if fullname == 'builtins.int.__add__':

return type_add

if fullname == 'builtins.int.__radd__':

return type_radd

return None

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

return TestPlugin