[fix] allow to modify _formatting attributes on CodeBlockNodes

redbaron.py

@@ -1021,6 +1021,9 @@ def _string_to_node_list(self, string, parent, on_attribute):
         if on_attribute == "value":
             return self.parse_code_block(string, parent=parent, on_attribute=on_attribute)
 
+        elif on_attribute.endswith("_formatting"):
+            return super(CodeBlockNode, self)._string_to_node_list(string, parent, on_attribute)
+
         else:
             raise Exception("Unhandled case")
 

tests/test_regressions.py

@@ -6,3 +6,9 @@ def test_mixmatch_with_redbaron_base_node_and_proxy_list_on_parent():
     red.insert(0, "baz")
     assert red[0].on_attribute == "root"
     assert red[0].parent is red
+
+
+def test_can_modify_formatting_attributes_on_codeblocknodes():
+    red = RedBaron("class Foo:\n    def bar(): pass")
+    red.class_.first_formatting = "    "  # shouldn't raise
+    red.def_.second_formatting = "      "  # same