From 5bed73958abf904e458722aeaa7d3f55a088b07e Mon Sep 17 00:00:00 2001
From: Elijah <elijahahianyo@gmail.com>
Date: Wed, 2 Oct 2024 17:27:41 +0000
Subject: [PATCH] use custom exception

---
 reflex/state.py            | 5 +++--
 reflex/utils/exceptions.py | 4 ++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/reflex/state.py b/reflex/state.py
index 0abca47038..3b35a2d893 100644
--- a/reflex/state.py
+++ b/reflex/state.py
@@ -71,6 +71,7 @@
     EventHandlerShadowsBuiltInStateMethod,
     ImmutableStateError,
     LockExpiredError,
+    SetUndefinedStateVarError,
 )
 from reflex.utils.exec import is_testing_env
 from reflex.utils.serializers import SerializedType, serialize, serializer
@@ -1218,7 +1219,7 @@ def __setattr__(self, name: str, value: Any):
             value: The value of the attribute.
 
         Raises:
-            AttributeError: If a value of a var is set without first defining it.
+            SetUndefinedStateVar: If a value of a var is set without first defining it.
         """
         if isinstance(value, MutableProxy):
             # unwrap proxy objects when assigning back to the state
@@ -1243,7 +1244,7 @@ def __setattr__(self, name: str, value: Any):
             and name not in self.vars
             and name not in self.get_skip_vars()
         ):
-            raise AttributeError(
+            raise SetUndefinedStateVarError(
                 f"The state variable '{name}' has not been defined in '{type(self).__name__}'. "
                 f"All state variables must be declared before they can be set."
             )
diff --git a/reflex/utils/exceptions.py b/reflex/utils/exceptions.py
index 95d68c3b8b..d77897bcde 100644
--- a/reflex/utils/exceptions.py
+++ b/reflex/utils/exceptions.py
@@ -111,3 +111,7 @@ class GeneratedCodeHasNoFunctionDefs(ReflexError):
 
 class PrimitiveUnserializableToJSON(ReflexError, ValueError):
     """Raised when a primitive type is unserializable to JSON. Usually with NaN and Infinity."""
+
+
+class SetUndefinedStateVarError(ReflexError, AttributeError):
+    """Raised when setting the value of a var without first declaring it."""