MutableProxy: do not rebind self for classmethods (#6045)

When the method's `__self__` is a class, then we just return the classmethod
value directly with no rebinding.

Author: masenf

reflex/istate/proxy.py

@@ -560,11 +560,15 @@ def __getattr__(self, __name: str) -> Any:
                 )
 
             if (
-                not isinstance(self.__wrapped__, Base)
-                or __name not in NEVER_WRAP_BASE_ATTRS
-            ) and hasattr(value, "__func__"):
+                (
+                    not isinstance(self.__wrapped__, Base)
+                    or __name not in NEVER_WRAP_BASE_ATTRS
+                )
+                and (func := getattr(value, "__func__", None)) is not None
+                and not inspect.isclass(getattr(value, "__self__", None))
+            ):
                 # Rebind `self` to the proxy on methods to capture nested mutations.
-                return functools.partial(value.__func__, self)  # pyright: ignore [reportFunctionMemberAccess, reportAttributeAccessIssue]
+                return functools.partial(func, self)
 
         if is_mutable_type(type(value)) and __name not in (
             "__wrapped__",

tests/units/test_state.py

@@ -2089,6 +2089,18 @@ def append_to_ls(self, item: dict):
         """
         self.ls.append(item)
 
+    @classmethod
+    def from_dict(cls, data: dict) -> ModelDC:
+        """Create an instance of ModelDC from a dictionary.
+
+        Args:
+            data: The dictionary to create the instance from.
+
+        Returns:
+            An instance of ModelDC.
+        """
+        return cls(**data)
+
 
 @pytest.mark.asyncio
 async def test_state_proxy(
@@ -3945,6 +3957,11 @@ def test_mutable_models():
     assert state.dirty_vars == set()
     state.dc.append_to_ls({"new": "item"})
     assert state.dirty_vars == {"dc"}
+    state.dirty_vars.clear()
+
+    dc_from_dict = state.dc.from_dict({"foo": "from_dict", "ls": []})
+    assert dc_from_dict == ModelDC(foo="from_dict", ls=[])
+    assert state.dirty_vars == set()
 
 
 def test_dict_and_get_delta():