Look in the metaclass, if defined, for members not found in the current class. Closes issue #306.

6 files changed, 74 insertions, 36 deletions

diff --git a/ChangeLog b/ChangeLog
index d533162..7b70fa7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -59,6 +59,9 @@ ChangeLog for Pylint
 
     * Don't emit 'unused-import' when a special object is imported
       (__all__, __doc__ etc.). Closes issue #309.
+ 
+    * Look in the metaclass, if defined, for members not found in the current
+      class. Closes issue #306.
 
 2014-07-26  --  1.3.0
 
diff --git a/checkers/typecheck.py b/checkers/typecheck.py
index 537a220..a8851a2 100644
--- a/checkers/typecheck.py
+++ b/checkers/typecheck.py
@@ -249,6 +249,20 @@ accessed. Python regular expressions are accepted.'}
                 # explicit skipping of module member access
                 if owner.root().name in self.config.ignored_modules:
                     continue
+                if isinstance(owner, astroid.Class):
+                    # Look up in the metaclass only if the owner is itself
+                    # a class.
+                    # TODO: getattr doesn't return by default members
+                    # from the metaclass, because handling various cases
+                    # of methods accessible from the metaclass itself
+                    # and/or subclasses only is too complicated for little to
+                    # no benefit.
+                    metaclass = owner.metaclass()
+                    try:
+                        if metaclass and metaclass.getattr(node.attrname):
+                            continue
+                    except NotFoundError:
+                        pass
                 missingattr.add((owner, name))
                 continue
             # stop on the first found
diff --git a/test/functional/class_members.py b/test/functional/class_members.py
new file mode 100644
index 0000000..d60458b
--- /dev/null
+++ b/test/functional/class_members.py
@@ -0,0 +1,51 @@
+""" Various tests for class members access. """

+# pylint: disable=R0903

+

+class MyClass(object):

+    """class docstring"""

+

+    def __init__(self):

+        """init"""

+        self.correct = 1

+

+    def test(self):

+        """test"""

+        self.correct += 2

+        self.incorrect += 2 # [no-member]

+        del self.havenot # [no-member]

+        self.nonexistent1.truc() # [no-member]

+        self.nonexistent2[1] = 'hehe' # [no-member]

+

+class XYZMixin(object):

+    """access to undefined members should be ignored in mixin classes by

+    default

+    """

+    def __init__(self):

+        print self.nonexistent

+

+

+class NewClass(object):

+    """use object.__setattr__"""

+    def __init__(self):

+        self.__setattr__('toto', 'tutu')

+

+from abc import ABCMeta

+

+class TestMetaclass(object):

+    """ Test attribute access for metaclasses. """

+    __metaclass__ = ABCMeta

+

+class Metaclass(type):

+    """ metaclass """

+    @classmethod

+    def test(mcs):

+        """ classmethod """

+

+class UsingMetaclass(object):

+    """ empty """

+    __metaclass__ = Metaclass

+

+TestMetaclass.register(int)

+UsingMetaclass.test()

+TestMetaclass().register(int) # [no-member]

+UsingMetaclass().test() # [no-member]

diff --git a/test/functional/class_members.txt b/test/functional/class_members.txt
new file mode 100644
index 0000000..0cb808f
--- /dev/null
+++ b/test/functional/class_members.txt
@@ -0,0 +1,6 @@
+no-member:14:MyClass.test:Instance of 'MyClass' has no 'incorrect' member

+no-member:15:MyClass.test:Instance of 'MyClass' has no 'havenot' member

+no-member:16:MyClass.test:Instance of 'MyClass' has no 'nonexistent1' member

+no-member:17:MyClass.test:Instance of 'MyClass' has no 'nonexistent2' member

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

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

diff --git a/test/input/func_class_members.py b/test/input/func_class_members.py
deleted file mode 100644
index ad147e5..0000000
--- a/test/input/func_class_members.py
+++ /dev/null
@@ -1,32 +0,0 @@
-# pylint: disable=R0903
-"""test class members"""
-
-__revision__ = ''
-
-class MyClass(object):
-    """class docstring"""
-
-    def __init__(self):
-        """init"""
-        self.correct = 1
-
-    def test(self):
-        """test"""
-        self.correct += 2
-        self.incorrect += 2
-        del self.havenot
-        self.nonexistent1.truc()
-        self.nonexistent2[1] = 'hehe'
-
-class XYZMixin(object):
-    """access to undefined members should be ignored in mixin classes by
-    default
-    """
-    def __init__(self):
-        print self.nonexistent
-
-
-class NewClass(object):
-    """use object.__setattr__"""
-    def __init__(self):
-        self.__setattr__('toto', 'tutu')
diff --git a/test/messages/func_class_members.txt b/test/messages/func_class_members.txt
deleted file mode 100644
index 054e21a..0000000
--- a/test/messages/func_class_members.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-E: 16:MyClass.test: Instance of 'MyClass' has no 'incorrect' member
-E: 17:MyClass.test: Instance of 'MyClass' has no 'havenot' member
-E: 18:MyClass.test: Instance of 'MyClass' has no 'nonexistent1' member
-E: 19:MyClass.test: Instance of 'MyClass' has no 'nonexistent2' member