Merge pull request #21279 from BerriAI/fix/tokenizer-cache-test-isolation

fix(test): clear tokenizer LRU cache for test isolation

tests/test_litellm/litellm_core_utils/test_token_counter.py

@@ -491,7 +491,20 @@ from unittest.mock import MagicMock, patch
 from litellm.utils import _select_tokenizer_helper, claude_json_str, encoding
 
 
+# Clear the cache at module load to ensure clean state
+_select_tokenizer_helper.cache_clear()
+
+
 class TestTokenizerSelection(unittest.TestCase):
+    def setUp(self):
+        """Clear the LRU cache before each test method.
+
+        The _select_tokenizer_helper function is decorated with @lru_cache,
+        which can cause cache hits from previous tests when running with
+        --dist=loadscope (tests from same file run on same worker).
+        """
+        _select_tokenizer_helper.cache_clear()
+
     @patch("litellm.utils.Tokenizer.from_pretrained")
     def test_llama3_tokenizer_api_failure(self, mock_from_pretrained):
         # Setup mock to raise an error