All type comments have as parent the corresponding astroid node

Until now they had as parent the builtin `ast` node which meant
we were operating with primitive objects instead of our own.

Close pylint-dev/pylint#3174

Author: PCManticore

ChangeLog

@@ -2,6 +2,18 @@
 astroid's ChangeLog
 ===================
 
+What's New in astroid 2.3.2?
+============================
+Release Date: TBA
+
+* All type comments have as parent the corresponding `astroid` node
+
+  Until now they had as parent the builtin `ast` node which meant
+  we were operating with primitive objects instead of our own.
+
+  Close PyCQA/pylint#3174
+
+
 What's New in astroid 2.3.1?
 ============================
 Release Date: 2019-09-30

astroid/node_classes.py

@@ -496,7 +496,9 @@ def scope(self):
         :returns: The first parent scope node.
         :rtype: Module or FunctionDef or ClassDef or Lambda or GenExpr
         """
-        return self.parent.scope()
+        if self.parent:
+            return self.parent.scope()
+        return None
 
     def root(self):
         """Return the root node of the syntax tree.

astroid/rebuilder.py

@@ -218,7 +218,9 @@ def visit_arguments(self, node, parent):
                 self.visit(arg.annotation, newnode) if arg.annotation else None
                 for arg in node.posonlyargs
             ]
-        type_comment_args = [self.check_type_comment(child) for child in node.args]
+        type_comment_args = [
+            self.check_type_comment(child, parent=newnode) for child in node.args
+        ]
 
         newnode.postinit(
             args=args,
@@ -250,7 +252,7 @@ def visit_assert(self, node, parent):
         newnode.postinit(self.visit(node.test, newnode), msg)
         return newnode
 
-    def check_type_comment(self, node):
+    def check_type_comment(self, node, parent):
         type_comment = getattr(node, "type_comment", None)
         if not type_comment:
             return None
@@ -261,7 +263,7 @@ def check_type_comment(self, node):
             # Invalid type comment, just skip it.
             return None
 
-        type_object = self.visit(type_comment_ast.body[0], node)
+        type_object = self.visit(type_comment_ast.body[0], parent=parent)
         if not isinstance(type_object, nodes.Expr):
             return None
 
@@ -289,8 +291,8 @@ def check_function_type_comment(self, node):
 
     def visit_assign(self, node, parent):
         """visit a Assign node by returning a fresh instance of it"""
-        type_annotation = self.check_type_comment(node)
         newnode = nodes.Assign(node.lineno, node.col_offset, parent)
+        type_annotation = self.check_type_comment(node, parent=newnode)
         newnode.postinit(
             targets=[self.visit(child, newnode) for child in node.targets],
             value=self.visit(node.value, newnode),
@@ -550,7 +552,7 @@ def visit_extslice(self, node, parent):
     def _visit_for(self, cls, node, parent):
         """visit a For node by returning a fresh instance of it"""
         newnode = cls(node.lineno, node.col_offset, parent)
-        type_annotation = self.check_type_comment(node)
+        type_annotation = self.check_type_comment(node, parent=newnode)
         newnode.postinit(
             target=self.visit(node.target, newnode),
             iter=self.visit(node.iter, newnode),
@@ -912,7 +914,7 @@ def visit_with(self, node, parent):
         else:
             optional_vars = None
 
-        type_annotation = self.check_type_comment(node)
+        type_annotation = self.check_type_comment(node, parent=newnode)
         newnode.postinit(
             items=[(expr, optional_vars)],
             body=[self.visit(child, newnode) for child in node.body],
@@ -1026,7 +1028,7 @@ def visit_child(child):
             var = _visit_or_none(child, "optional_vars", self, newnode)
             return expr, var
 
-        type_annotation = self.check_type_comment(node)
+        type_annotation = self.check_type_comment(node, parent=newnode)
         newnode.postinit(
             items=[visit_child(child) for child in node.items],
             body=[self.visit(child, newnode) for child in node.body],

astroid/tests/unittest_nodes.py

@@ -1195,5 +1195,26 @@ def test_parse_fstring_debug_mode():
     assert node.as_string() == "f'3={3}'"
 
 
+@pytest.mark.skipif(not HAS_TYPED_AST, reason="requires typed_ast")
+def test_parse_type_comments_with_proper_parent():
+    code = """
+    class D: #@
+        @staticmethod
+        def g(
+                x  # type: np.array
+        ):
+            pass
+    """
+    node = astroid.extract_node(code)
+    func = node.getattr("g")[0]
+    type_comments = func.args.type_comment_args
+    assert len(type_comments) == 1
+
+    type_comment = type_comments[0]
+    assert isinstance(type_comment, astroid.Attribute)
+    assert isinstance(type_comment.parent, astroid.Expr)
+    assert isinstance(type_comment.parent.parent, astroid.Arguments)
+
+
 if __name__ == "__main__":
     unittest.main()