test(completion): web_search_options auto-bridge to Responses API

tests/test_litellm/test_web_search_auto_bridge.py

@@ -0,0 +1,132 @@
+"""
+Test automatic bridging of web_search_options to Responses API
+when a model only supports /v1/responses.
+"""
+
+import os
+import sys
+from unittest.mock import patch
+
+sys.path.insert(0, os.path.abspath("../.."))
+
+import pytest
+
+from litellm.main import responses_api_bridge_check
+
+
+def _make_model_info(
+    mode="chat",
+    supports_web_search=False,
+    supported_endpoints=None,
+):
+    """Return a minimal model_info dict for mocking."""
+    return {
+        "key": "openai/gpt-5.4",
+        "max_tokens": 100000,
+        "max_input_tokens": 1000000,
+        "max_output_tokens": 100000,
+        "input_cost_per_token": 0.000003,
+        "output_cost_per_token": 0.000015,
+        "litellm_provider": "openai",
+        "mode": mode,
+        "supports_web_search": supports_web_search,
+        "supported_endpoints": supported_endpoints,
+    }
+
+
+class TestWebSearchAutoBridge:
+    """Test that web_search_options triggers auto-bridge to Responses API
+    when the model supports web search only via /v1/responses."""
+
+    @patch("litellm.main._get_model_info_helper")
+    def test_auto_bridge_when_model_only_supports_responses(self, mock_get_model_info):
+        """Model supports web search + /v1/responses but mode is chat.
+        web_search_options should trigger bridge to responses mode."""
+        mock_get_model_info.return_value = _make_model_info(
+            mode="chat",
+            supports_web_search=True,
+            supported_endpoints=["/v1/chat/completions", "/v1/responses"],
+        )
+
+        model_info, updated_model = responses_api_bridge_check(
+            model="gpt-5.4",
+            custom_llm_provider="openai",
+            web_search_options={},
+        )
+
+        assert model_info.get("mode") == "responses"
+        assert updated_model == "gpt-5.4"
+
+    @patch("litellm.main._get_model_info_helper")
+    def test_no_bridge_without_web_search_options(self, mock_get_model_info):
+        """Without web_search_options, no auto-bridge even if model supports it."""
+        mock_get_model_info.return_value = _make_model_info(
+            mode="chat",
+            supports_web_search=True,
+            supported_endpoints=["/v1/chat/completions", "/v1/responses"],
+        )
+
+        model_info, updated_model = responses_api_bridge_check(
+            model="gpt-5.4",
+            custom_llm_provider="openai",
+            web_search_options=None,
+        )
+
+        assert model_info.get("mode") == "chat"
+        assert updated_model == "gpt-5.4"
+
+    @patch("litellm.main._get_model_info_helper")
+    def test_no_bridge_when_no_responses_endpoint(self, mock_get_model_info):
+        """Model supports web search but NOT /v1/responses -- no bridge."""
+        mock_get_model_info.return_value = _make_model_info(
+            mode="chat",
+            supports_web_search=True,
+            supported_endpoints=["/v1/chat/completions"],
+        )
+
+        model_info, updated_model = responses_api_bridge_check(
+            model="gpt-4o",
+            custom_llm_provider="openai",
+            web_search_options={},
+        )
+
+        assert model_info.get("mode") == "chat"
+
+    @patch("litellm.main._get_model_info_helper")
+    def test_no_bridge_when_supports_web_search_false(self, mock_get_model_info):
+        """Model has /v1/responses but supports_web_search is False -- no bridge."""
+        mock_get_model_info.return_value = _make_model_info(
+            mode="chat",
+            supports_web_search=False,
+            supported_endpoints=["/v1/chat/completions", "/v1/responses"],
+        )
+
+        model_info, updated_model = responses_api_bridge_check(
+            model="some-model",
+            custom_llm_provider="openai",
+            web_search_options={},
+        )
+
+        assert model_info.get("mode") == "chat"
+
+    @patch("litellm.main._get_model_info_helper")
+    def test_no_bridge_when_already_responses_mode(self, mock_get_model_info):
+        """Model is already in responses mode -- no double-bridge."""
+        mock_get_model_info.return_value = _make_model_info(
+            mode="responses",
+            supports_web_search=True,
+            supported_endpoints=["/v1/responses"],
+        )
+
+        model_info, updated_model = responses_api_bridge_check(
+            model="gpt-5.4",
+            custom_llm_provider="openai",
+            web_search_options={},
+        )
+
+        # Still responses, but did not change -- already was responses
+        assert model_info.get("mode") == "responses"
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])