[Bug Fix] Perplexity - LiteLLM doesn't support 'web_search_options' for Perplexity' Sonar Pro model (#11983)

* TestPerplexityWebSearch

* use supports_web_search

* Update tests/test_litellm/llms/perplexity/test_perplexity.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

litellm/llms/perplexity/chat/transformation.py

@@ -55,4 +55,13 @@ class PerplexityChatConfig(OpenAIGPTConfig):
                 base_openai_params.append("reasoning_effort")
         except Exception as e:
             verbose_logger.debug(f"Error checking if model supports reasoning: {e}")
+        
+        try:
+            if litellm.supports_web_search(
+                model=model, custom_llm_provider=self.custom_llm_provider
+            ):
+                base_openai_params.append("web_search_options")
+        except Exception as e:
+            verbose_logger.debug(f"Error checking if model supports web search: {e}")
+        
         return base_openai_params

tests/test_litellm/llms/perplexity/test_perplexity.py

@@ -0,0 +1,25 @@
+import os
+import sys
+
+sys.path.insert(0, os.path.abspath("../../.."))
+
+import pytest
+
+
+class TestPerplexityWebSearch:
+    """Test suite for Perplexity web search functionality."""
+
+    @pytest.mark.parametrize(
+        "model",
+        ["perplexity/sonar", "perplexity/sonar-pro"]
+    )
+    def test_web_search_options_in_supported_params(self, model):
+        """
+        Test that web_search_options is in the list of supported parameters for Perplexity sonar models
+        """
+        from litellm.llms.perplexity.chat.transformation import PerplexityChatConfig
+        
+        config = PerplexityChatConfig()
+        supported_params = config.get_supported_openai_params(model=model)
+        
+        assert "web_search_options" in supported_params, f"web_search_options should be supported for {model}"