Lookup in the implicit metaclass when checking for no-member.

If the class in question has an implicit metaclass, which is
True for new style classes, then we can look into in when we are doing
a dot access on it. Closes issue #438.

6 files changed, 25 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 8b356b1..6db44aa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -70,6 +70,10 @@ ChangeLog for Pylint
       Since we don't know what those bases might add, we simply ignore
       the error in this case. 
 
+    * Lookup in the implicit metaclass when checking for no-member,
+      if the class in question has an implicit metaclass, which is
+      True for new style classes. Closes issue #438.
+
 
 2015-03-14 -- 1.4.3
 
diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index ed3c901..c8eed30 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -126,7 +126,7 @@ def _emit_no_member(owner, owner_name, attrname,
         # of methods accessible from the metaclass itself
         # and/or subclasses only is too complicated for little to
         # no benefit.
-        metaclass = owner.metaclass()
+        metaclass = owner.metaclass() or owner.implicit_metaclass()
         try:
             if metaclass and metaclass.getattr(attrname):
                 return False
diff --git a/pylint/test/functional/class_members_py27.py b/pylint/test/functional/class_members_py27.py
index 5bbbb65..415a890 100644
--- a/pylint/test/functional/class_members_py27.py
+++ b/pylint/test/functional/class_members_py27.py
@@ -1,5 +1,5 @@
 """ Various tests for class members access. """

-# pylint: disable=R0903,print-statement,no-absolute-import, metaclass-assignment,import-error,no-init

+# pylint: disable=R0903,print-statement,no-absolute-import, metaclass-assignment,import-error,no-init,missing-docstring

 from missing import Missing

 class MyClass(object):

     """class docstring"""

@@ -55,3 +55,11 @@ class NoKnownBases(Missing):
     """Don't emit no-member if we don't know the bases of a class."""

 

 NoKnownBases().lalala()

+

+

+class MetaClass(object):

+    """Look some methods in the implicit metaclass."""

+

+    @classmethod

+    def whatever(cls):

+        return cls.mro() + cls.missing() # [no-member]

diff --git a/pylint/test/functional/class_members_py27.txt b/pylint/test/functional/class_members_py27.txt
index e5e6005..3a3be0e 100644
--- a/pylint/test/functional/class_members_py27.txt
+++ b/pylint/test/functional/class_members_py27.txt
@@ -4,3 +4,4 @@ no-member:16:MyClass.test:Instance of 'MyClass' has no 'nonexistent1' member:INF
 no-member:17:MyClass.test:Instance of 'MyClass' has no 'nonexistent2' member:INFERENCE
 no-member:50::Instance of 'TestMetaclass' has no 'register' member:INFERENCE
 no-member:51::Instance of 'UsingMetaclass' has no 'test' member:INFERENCE
+no-member:65:MetaClass.whatever:Class 'MetaClass' has no 'missing' member:INFERENCE
diff --git a/pylint/test/functional/class_members_py30.py b/pylint/test/functional/class_members_py30.py
index b8bc109..8c27703 100644
--- a/pylint/test/functional/class_members_py30.py
+++ b/pylint/test/functional/class_members_py30.py
@@ -1,5 +1,5 @@
 """ Various tests for class members access. """

-# pylint: disable=R0903,import-error,no-init

+# pylint: disable=R0903,import-error,no-init,missing-docstring

 from missing import Missing

 class MyClass(object):

     """class docstring"""

@@ -53,3 +53,11 @@ class NoKnownBases(Missing):
     """Don't emit no-member if we don't know the bases of a class."""

 

 NoKnownBases().lalala()

+

+

+class MetaClass(object):

+    """Look some methods in the implicit metaclass."""

+

+    @classmethod

+    def whatever(cls):

+        return cls.mro() + cls.missing() # [no-member]

diff --git a/pylint/test/functional/class_members_py30.txt b/pylint/test/functional/class_members_py30.txt
index 4696579..d9163ec 100644
--- a/pylint/test/functional/class_members_py30.txt
+++ b/pylint/test/functional/class_members_py30.txt
@@ -4,3 +4,4 @@ no-member:16:MyClass.test:Instance of 'MyClass' has no 'nonexistent1' member:INF
 no-member:17:MyClass.test:Instance of 'MyClass' has no 'nonexistent2' member:INFERENCE

 no-member:48::Instance of 'TestMetaclass' has no 'register' member:INFERENCE

 no-member:49::Instance of 'UsingMetaclass' has no 'test' member:INFERENCE

+no-member:63:MetaClass.whatever:Class 'MetaClass' has no 'missing' member:INFERENCE
\ No newline at end of file