Address code review feedback: Windows-only patch, proper restoration, improved tests

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/patches/litellm_patch.py

@@ -4,6 +4,10 @@ Patch for litellm to fix UnicodeDecodeError on Windows systems.
 This patch ensures that all file open operations in litellm use UTF-8 encoding,
 which prevents UnicodeDecodeError when loading JSON files on Windows systems
 where the default encoding is cp1252 or cp1254.
+
+WARNING: This patch monkey-patches the built-in open() function globally on Windows. 
+It forces UTF-8 encoding on all text-mode file opens, which could affect third-party 
+libraries expecting default platform encodings. Apply with caution and test comprehensively.
 """
 
 import builtins
@@ -12,6 +16,7 @@ import io
 import json
 import logging
 import os
+import sys
 from importlib import resources
 from typing import Any, Optional, Union
 
@@ -19,12 +24,26 @@ logger = logging.getLogger(__name__)
 
 
 def apply_patches():
-    """Apply all patches to fix litellm encoding issues."""
-    logger.info("Applying litellm encoding patches")
+    """
+    Apply patches to fix litellm encoding issues on Windows systems.
     
-    original_open = builtins.open
+    This function only applies the patch on Windows platforms where the issue occurs.
+    It stores the original open function for proper restoration later.
+    """
+    # Only apply patch on Windows systems
+    if sys.platform != "win32":
+        logger.debug("Skipping litellm encoding patches on non-Windows platform")
+        return
     
-    @functools.wraps(original_open)
+    if hasattr(builtins, '_original_open'):
+        logger.debug("Litellm encoding patches already applied")
+        return
+    
+    logger.debug("Applying litellm encoding patches on Windows")
+    
+    builtins._original_open = builtins.open
+    
+    @functools.wraps(builtins._original_open)
     def patched_open(
         file, mode='r', buffering=-1, encoding=None, 
         errors=None, newline=None, closefd=True, opener=None
@@ -32,18 +51,23 @@ def apply_patches():
         if 'r' in mode and encoding is None and 'b' not in mode:
             encoding = 'utf-8'
         
-        return original_open(
+        return builtins._original_open(
             file, mode, buffering, encoding, 
             errors, newline, closefd, opener
         )
     
     builtins.open = patched_open
     
-    logger.info("Successfully applied litellm encoding patches")
+    logger.debug("Successfully applied litellm encoding patches")
 
 
 def remove_patches():
-    """Remove all patches (for testing purposes)."""
+    """
+    Remove all patches (for testing purposes).
+    
+    This function properly restores the original open function if it was patched.
+    """
     if hasattr(builtins, '_original_open'):
         builtins.open = builtins._original_open
-        logger.info("Removed litellm encoding patches")
+        delattr(builtins, '_original_open')
+        logger.debug("Removed litellm encoding patches")

tests/litellm_tests/test_encoding.py

@@ -4,14 +4,21 @@ import sys
 import unittest
 from unittest.mock import mock_open, patch
 
-import pytest
-
 from crewai.llm import LLM
+from crewai.patches.litellm_patch import apply_patches, remove_patches
 
 
 class TestLitellmEncoding(unittest.TestCase):
     """Test that the litellm encoding patch works correctly."""
 
+    def setUp(self):
+        """Set up the test environment by applying the patch."""
+        apply_patches()
+
+    def tearDown(self):
+        """Clean up the test environment by removing the patch."""
+        remove_patches()
+
     def test_json_load_with_utf8_encoding(self):
         """Test that json.load is called with UTF-8 encoding."""
         
@@ -25,3 +32,20 @@ class TestLitellmEncoding(unittest.TestCase):
             with open('test.json', 'r') as f:
                 data = json.load(f)
                 self.assertEqual(data['test'], '日本語テキスト')
+    
+    def test_without_patch(self):
+        """Test that demonstrates the issue without the patch."""
+        remove_patches()
+        
+        mock_content = '{"test": "日本語テキスト"}'  # Japanese text that would fail with cp1252
+        
+        with patch('sys.platform', 'win32'):
+            mock_open_without_encoding = mock_open(read_data=mock_content)
+            mock_open_without_encoding.side_effect = UnicodeDecodeError('cp1252', b'\x81', 0, 1, 'invalid start byte')
+            
+            with patch('builtins.open', mock_open_without_encoding):
+                with self.assertRaises(UnicodeDecodeError):
+                    with open('test.json', 'r') as f:
+                        json.load(f)
+        
+        apply_patches()