address greptile review: remove unused import, normalize model lookup, add xhigh tests

- Remove unused _get_model_info_helper import
- Normalize model via get_llm_provider in _is_reasoning_effort_level_explicitly_disabled
  so provider-prefixed names (openai/gpt-5.4-mini) resolve correctly
- Add test_gpt5_4_mini_allows_reasoning_effort_xhigh
- Add test_gpt5_4_nano_allows_reasoning_effort_xhigh
- Add test_gpt5_4_mini_provider_prefixed_rejects_minimal
- Extend test_gpt5_minimal_explicitly_disabled_check for openai/gpt-5.4-mini

litellm/llms/openai/chat/gpt_5_transformation.py

@@ -3,7 +3,7 @@
 from typing import Optional, Union
 
 import litellm
-from litellm.utils import _get_model_cost_key, _get_model_info_helper, _supports_factory
+from litellm.utils import _get_model_cost_key, _supports_factory
 
 from .gpt_transformation import OpenAIGPTConfig
 
@@ -125,11 +125,16 @@ class OpenAIGPT5Config(OpenAIGPTConfig):
         supported (i.e. this method returns False = not disabled).
 
         Use this for opt-out checks where unknown models should be allowed through.
+        Normalizes the model via get_llm_provider so provider-prefixed names
+        (e.g. openai/gpt-5.4-mini) resolve correctly.
         """
         try:
+            normalized_model, _, _, _ = litellm.get_llm_provider(
+                model=model, custom_llm_provider=None
+            )
             key = f"supports_{level}_reasoning_effort"
-            cost_key = _get_model_cost_key(model)
-            entry = litellm.model_cost.get(cost_key or model) or {}
+            cost_key = _get_model_cost_key(normalized_model)
+            entry = litellm.model_cost.get(cost_key or normalized_model) or {}
             val = entry.get(key)
             return val is False
         except Exception:

tests/test_litellm/llms/openai/test_gpt5_transformation.py

@@ -324,6 +324,28 @@ def test_gpt5_4_pro_allows_reasoning_effort_xhigh(config: OpenAIConfig):
     assert params["reasoning_effort"] == "xhigh"
 
 
+def test_gpt5_4_mini_allows_reasoning_effort_xhigh(config: OpenAIConfig):
+    """gpt-5.4-mini supports reasoning_effort='xhigh'."""
+    params = config.map_openai_params(
+        non_default_params={"reasoning_effort": "xhigh"},
+        optional_params={},
+        model="gpt-5.4-mini",
+        drop_params=False,
+    )
+    assert params["reasoning_effort"] == "xhigh"
+
+
+def test_gpt5_4_nano_allows_reasoning_effort_xhigh(config: OpenAIConfig):
+    """gpt-5.4-nano supports reasoning_effort='xhigh'."""
+    params = config.map_openai_params(
+        non_default_params={"reasoning_effort": "xhigh"},
+        optional_params={},
+        model="gpt-5.4-nano",
+        drop_params=False,
+    )
+    assert params["reasoning_effort"] == "xhigh"
+
+
 def test_gpt5_4_allows_reasoning_effort_minimal(config: OpenAIConfig):
     """gpt-5.4 supports reasoning_effort='minimal'."""
     params = config.map_openai_params(
@@ -368,6 +390,17 @@ def test_gpt5_4_nano_rejects_reasoning_effort_minimal(config: OpenAIConfig):
         )
 
 
+def test_gpt5_4_mini_provider_prefixed_rejects_minimal(config: OpenAIConfig):
+    """openai/gpt-5.4-mini correctly rejects minimal (model lookup normalizes prefix)."""
+    with pytest.raises(litellm.utils.UnsupportedParamsError):
+        config.map_openai_params(
+            non_default_params={"reasoning_effort": "minimal"},
+            optional_params={},
+            model="openai/gpt-5.4-mini",
+            drop_params=False,
+        )
+
+
 def test_gpt5_drops_reasoning_effort_minimal_when_requested(config: OpenAIConfig):
     """reasoning_effort='minimal' is dropped for unsupported models when drop_params=True."""
     params = config.map_openai_params(
@@ -414,6 +447,7 @@ def test_gpt5_minimal_explicitly_disabled_check(gpt5_config: OpenAIGPT5Config):
 
     Models with supports_minimal_reasoning_effort=false → disabled.
     Models with supports_minimal_reasoning_effort=true (or missing) → not disabled.
+    Provider-prefixed models (openai/gpt-5.4-mini) are normalized before lookup.
     """
     assert gpt5_config._is_reasoning_effort_level_explicitly_disabled(
         "gpt-5.4-mini", "minimal"
@@ -421,6 +455,9 @@ def test_gpt5_minimal_explicitly_disabled_check(gpt5_config: OpenAIGPT5Config):
     assert gpt5_config._is_reasoning_effort_level_explicitly_disabled(
         "gpt-5.4-nano", "minimal"
     )
+    assert gpt5_config._is_reasoning_effort_level_explicitly_disabled(
+        "openai/gpt-5.4-mini", "minimal"
+    )
     assert not gpt5_config._is_reasoning_effort_level_explicitly_disabled(
         "gpt-5.4", "minimal"
     )