fix(lint): remove duplicate test import, LIT002 dict literal, and mock-echo otel test

- drop redundant in-function import of callback_config_error (F811)
- avoid the `or {}` mutable literal in _set_langfuse_specific_attributes (LIT002)
- rewrite the dynamic-env otel test to observe span.set_attribute output
  instead of patching litellm internals (TQ002/TQ008)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

litellm/integrations/langfuse/langfuse_otel.py

@@ -226,10 +226,10 @@ class LangfuseOtelLogger(OpenTelemetry):
         from litellm.integrations.arize._utils import safe_set_attribute
         from litellm.litellm_core_utils.safe_json_dumps import safe_dumps
 
-        dynamic_params: Final = kwargs.get("standard_callback_dynamic_params") or {}
-        langfuse_environment: Final = dynamic_params.get("langfuse_environment") or os.environ.get(
-            "LANGFUSE_TRACING_ENVIRONMENT"
-        )
+        dynamic_params: Final = kwargs.get("standard_callback_dynamic_params")
+        langfuse_environment: Final = (
+            dynamic_params.get("langfuse_environment") if dynamic_params else None
+        ) or os.environ.get("LANGFUSE_TRACING_ENVIRONMENT")
         if langfuse_environment:
             safe_set_attribute(
                 span,

tests/test_litellm/integrations/test_langfuse_otel.py

@@ -139,7 +139,15 @@ class TestLangfuseOtelIntegration:
 
     def test_set_langfuse_environment_attribute_prefers_dynamic_param(self):
         """Per-key/team langfuse_environment beats the deployment env var."""
-        mock_span = MagicMock()
+
+        class _RecordingSpan:
+            def __init__(self):
+                self.attributes = {}
+
+            def set_attribute(self, key, value):
+                self.attributes[key] = value
+
+        span = _RecordingSpan()
         mock_kwargs = {
             "standard_callback_dynamic_params": {
                 "langfuse_environment": "team-a-env"
@@ -149,16 +157,11 @@ class TestLangfuseOtelIntegration:
         with patch.dict(
             os.environ, {"LANGFUSE_TRACING_ENVIRONMENT": "deployment-wide"}
         ):
-            with patch(
-                "litellm.integrations.arize._utils.safe_set_attribute"
-            ) as mock_safe_set_attribute:
-                LangfuseOtelLogger._set_langfuse_specific_attributes(
-                    mock_span, mock_kwargs, {}
-                )
+            LangfuseOtelLogger._set_langfuse_specific_attributes(
+                span, mock_kwargs, {}
+            )
 
-                mock_safe_set_attribute.assert_called_once_with(
-                    mock_span, "langfuse.environment", "team-a-env"
-                )
+        assert span.attributes["langfuse.environment"] == "team-a-env"
 
     def test_extract_langfuse_metadata_basic(self):
         """Ensure metadata is correctly pulled from litellm_params."""

tests/test_litellm/proxy/common_utils/test_callback_config_validation.py

@@ -4,10 +4,6 @@ from litellm.proxy.common_utils.callback_config_validation import (
 
 
 def test_callback_config_error_rejects_invalid_langfuse_environment():
-    from litellm.proxy.common_utils.callback_config_validation import (
-        callback_config_error,
-    )
-
     for callback in ["langfuse", "langfuse_otel"]:
         error = callback_config_error(callback, {"langfuse_environment": "Production"})
         assert error is not None and "langfuse_environment" in error