W0223 does not get raised correctly

[alibeyram]

Bug description

The not implemented warning does not get raised

here is a simple code that shows it

from abc import ABC, abstractmethod


class Base(ABC):
    @abstractmethod
    def do_something(self):
        pass


class Derived(Base):
    def do_something_else(self):
        pass

One way to test it is to recreate abc.ABC and use that for inheriting

from abc import ABCMeta, abstractmethod


class MYABC(metaclass=ABCMeta):
   __slots__ = ()


class Base(MYABC):
   @abstractmethod
   def do_something(self):
       pass


class Derived(Base):  #### the W0223:abstract-method raised here
   def do_something_else(self):
       pass

### Configuration

_No response_

### Command used

```shell
pylint test.py

Pylint output

Your code has been rated at 10.00/10

Expected behavior

W0223: Method 'do_something' is abstract in class 'Base' but is not overridden in child class 'Derived' (abstract-method)

Pylint version

pylint 3.3.1
astroid 3.3.4
Python 3.12.5 | packaged by conda-forge | (main, Aug  8 2024, 18:32:50) [Clang 16.0.6 ]

OS / Environment

No response

Additional dependencies

No response

[alibeyram]

@mbyrnepr2 are you gonna merge the PR?

[mbyrnepr2]

@alibeyram I need to assess the output of the CI primer results to make sure the behaviour is expected. It seems the change triggers the message quite a bit more with the PR.

[mbyrnepr2]

After looking into this further, and with the helpful output of the home-assistant primer in the CI, I think the original example is not a false negative since we don't know if the Derived subclass will be instantiated or not. If we emit abstract-method for Derived we get potentially a lot of false positives as can be seen from the home-assistant output.

Here is a manufactured example which is something like the home-assistant structure where we have subclasses of the original abc.ABC class, each implementing some of abstractmethods:

# Python is happy to instantiate Class3 since it implements all 3 abstractmethods.
import abc


class Base(abc.ABC):
    @abc.abstractmethod
    def method1(self):
        print("abstract")

    @abc.abstractmethod
    def method2(self):
        print("abstract")

    @abc.abstractmethod
    def method3(self):
        print("abstract")


class Class1(Base):
    def method1(self):
        print("method1 implemented")


class Class2(Class1):
    def method2(self):
        print("method2 implemented")


class Class3(Class2):
    """Concrete class with all abstract methods implemented"""
    def method3(self):
        print("method3 implemented")


myclass = Class3()

I'll change the label to false positive for the second example that was provided:

from abc import ABCMeta, abstractmethod


class MYABC(metaclass=ABCMeta):
   __slots__ = ()


class Base(MYABC):
   @abstractmethod
   def do_something(self):
       pass


class Derived(Base):  #### the W0223:abstract-method raised here
   def do_something_else(self):
       pass

[mbyrnepr2]

Also looks related to #7950