[classes checker] fix access-member-before-definition false negative wrt aug assign. Closes #164

1 files changed, 17 insertions, 0 deletions

diff --git a/checkers/classes.py b/checkers/classes.py
index 6dd5df0..f5e2783 100644
--- a/checkers/classes.py
+++ b/checkers/classes.py
@@ -458,6 +458,10 @@ a metaclass class method.'}
 
         self._check_protected_attribute_access(node)
 
+    def visit_assattr(self, node):
+        if isinstance(node.ass_type(), astroid.AugAssign) and self.is_first_attr(node):
+            self._accessed[-1].setdefault(node.attrname, []).append(node)
+
     @check_messages('protected-access')
     def visit_assign(self, assign_node):
         node = assign_node.targets[0]
@@ -540,6 +544,19 @@ a metaclass class method.'}
             except astroid.NotFoundError:
                 pass
             else:
+                # filter out augment assignment nodes
+                defstmts = [stmt for stmt in defstmts if stmt not in nodes]
+                if not defstmts:
+                    # only augment assignment for this node, no-member should be
+                    # triggered by the typecheck checker
+                    continue
+                # filter defstmts to only pick the first one when there are
+                # several assignments in the same scope
+                scope = defstmts[0].scope()
+                defstmts = [stmt for i, stmt in enumerate(defstmts)
+                            if i == 0 or stmt.scope() is not scope]
+                # if there are still more than one, don't attempt to be smarter
+                # than we can be
                 if len(defstmts) == 1:
                     defstmt = defstmts[0]
                     # check that if the node is accessed in the same method as