From a13b5a60914210352755219364eadb3dd19e10ec Mon Sep 17 00:00:00 2001
From: krassowski <5832902+krassowski@users.noreply.github.com>
Date: Mon, 10 Jun 2024 10:25:51 +0100
Subject: [PATCH] Prevent overriding `server_settings` on base provider class

---
 .../jupyter-ai-magics/jupyter_ai_magics/providers.py | 12 ++++++++++++
 .../tests/test_provider_metaclass.py                 | 11 ++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/packages/jupyter-ai-magics/jupyter_ai_magics/providers.py b/packages/jupyter-ai-magics/jupyter_ai_magics/providers.py
index bef7efacc..3d39b22f4 100644
--- a/packages/jupyter-ai-magics/jupyter_ai_magics/providers.py
+++ b/packages/jupyter-ai-magics/jupyter_ai_magics/providers.py
@@ -197,6 +197,18 @@ def __new__(mcs, name, bases, namespace, **kwargs):
 
         return cls
 
+    @property
+    def server_settings(cls):
+        return cls._server_settings
+
+    @server_settings.setter
+    def server_settings(cls, value):
+        if cls._server_settings is not None:
+            raise AttributeError("'server_settings' attribute was already set")
+        cls._server_settings = value
+
+    _server_settings = None
+
 
 class BaseProvider(BaseModel, metaclass=ProviderMetaclass):
     #
diff --git a/packages/jupyter-ai-magics/jupyter_ai_magics/tests/test_provider_metaclass.py b/packages/jupyter-ai-magics/jupyter_ai_magics/tests/test_provider_metaclass.py
index ddf99a245..359fe3774 100644
--- a/packages/jupyter-ai-magics/jupyter_ai_magics/tests/test_provider_metaclass.py
+++ b/packages/jupyter-ai-magics/jupyter_ai_magics/tests/test_provider_metaclass.py
@@ -1,8 +1,10 @@
+from types import MappingProxyType
 from typing import ClassVar, Optional
 
 from langchain.pydantic_v1 import BaseModel
+from pytest import raises
 
-from ..providers import ProviderMetaclass
+from ..providers import BaseProvider, ProviderMetaclass
 
 
 def test_provider_metaclass():
@@ -24,3 +26,10 @@ class Child(Base, Parent, metaclass=ProviderMetaclass):
         test: ClassVar[str] = "expected"
 
     assert Child.test == "expected"
+
+
+def test_base_provider_server_settings_read_only():
+    BaseProvider.server_settings = MappingProxyType({})
+
+    with raises(AttributeError, match="'server_settings' attribute was already set"):
+        BaseProvider.server_settings = MappingProxyType({})