Pylint: False positive: no-member on "property"-like decorator

[TBoshoven]

Steps to reproduce

1. Have Pylint (1.6.4) evaluate the following snippet:

   class prop(object):
      def __init__(self, fn):
          self.value = 5
   
   class my_class(object):
      @prop
      def my_property(self):
          pass
   
   print(my_class().my_property.value)
   

   Current behavior

Pylint returns the following, even with prop added to property_classes:
E: 10, 6: Method 'my_property' has no 'value' member (no-member)

Expected behavior

No no-member errors. A decorated function should not be assumed to be a function.

pylint --version output

    No config file found, using default configuration
    pylint 1.6.4, 
    astroid 1.4.8
    Python 3.5.2 (default, Jun 28 2016, 08:46:01) 
    [GCC 6.1.1 20160602]

[ngeraedts]

I've run into a similar issue with value injection on our unit tests. The following snippet runs without issue under pytest, but throws a no-member error under pylint.

from unittest import TestCase

def with_value(Cls):
    Cls_setUp = Cls.setUp

    def _setUp(self):
        self.value = 5
        self.addCleanup(delattr, self, 'value')
        Cls_setUp(self)

    Cls.setUp = _setUp

    return Cls

@with_value
class TestValue(TestCase):
    def test_value(self):
        value = self.value
        self.assertEqual(value, 5)

pylint --version

pylint 1.6.4,
astroid 1.4.8
Python 2.7.9 (default, Sep 26 2016, 12:51:32)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)]

[craiga]

Is this a duplicate of #1061 ?

[Xunnamius]

Bug still bites in 2019. My case is similar, I believe:

def _experiment(name):
    def __experiment(fn):
        fn.experiment_name = name
        return fn
    return __experiment

class Librunner():
    ...
@_experiment('sequential_freerun')
    def sequentialFreerun(self, some_parameter):
        ...

lib = Librunner()

experiments = [
    lib.sequentialFreerun
]

runFn = experiments[0]
print(runFn.experiment_name)

Error: Method 'sequentialFreerun' has no 'experiment_name' member

pylint 2.3.1
astroid 2.2.5
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD64)]