add tests for Perplexity provider handling in LLM module

crates/brightstaff/src/handlers/llm/mod.rs

@@ -782,3 +782,104 @@ async fn get_provider_info(
         (hermesllm::ProviderId::OpenAI, None, false)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{get_provider_info, get_upstream_path};
+    use common::configuration::{LlmProvider, LlmProviderType};
+    use common::llm_providers::LlmProviders;
+    use hermesllm::apis::OpenAIApi;
+    use hermesllm::clients::SupportedAPIsFromClient;
+    use std::sync::Arc;
+    use tokio::sync::RwLock;
+
+    fn build_provider(name: &str, model: &str) -> LlmProvider {
+        LlmProvider {
+            name: name.to_string(),
+            provider_interface: LlmProviderType::OpenAI,
+            access_key: Some("test_key".to_string()),
+            model: Some(model.to_string()),
+            default: Some(false),
+            ..Default::default()
+        }
+    }
+
+    fn providers_lock(providers: Vec<LlmProvider>) -> Arc<RwLock<LlmProviders>> {
+        Arc::new(RwLock::new(
+            LlmProviders::try_from(providers).expect("test providers should be valid"),
+        ))
+    }
+
+    #[tokio::test]
+    async fn test_get_provider_info_marks_perplexity_as_unversioned() {
+        let providers = providers_lock(vec![build_provider("perplexity/sonar-pro", "sonar-pro")]);
+
+        let (provider_id, prefix, use_unversioned_paths) =
+            get_provider_info(&providers, "perplexity/sonar-pro").await;
+
+        assert_eq!(provider_id, hermesllm::ProviderId::OpenAI);
+        assert_eq!(prefix, None);
+        assert!(use_unversioned_paths);
+    }
+
+    #[tokio::test]
+    async fn test_get_upstream_path_for_perplexity_uses_unversioned_chat_endpoint() {
+        let providers = providers_lock(vec![build_provider("perplexity/sonar-pro", "sonar-pro")]);
+
+        let upstream_path = get_upstream_path(
+            &providers,
+            "perplexity/sonar-pro",
+            "/v1/chat/completions",
+            "sonar-pro",
+            false,
+        )
+        .await;
+
+        assert_eq!(upstream_path, "/chat/completions");
+    }
+
+    #[tokio::test]
+    async fn test_get_upstream_path_for_non_perplexity_keeps_v1_chat_endpoint() {
+        let providers = providers_lock(vec![build_provider("openai/gpt-4o-mini", "gpt-4o-mini")]);
+
+        let upstream_path = get_upstream_path(
+            &providers,
+            "openai/gpt-4o-mini",
+            "/v1/chat/completions",
+            "gpt-4o-mini",
+            false,
+        )
+        .await;
+
+        assert_eq!(upstream_path, "/v1/chat/completions");
+    }
+
+    #[tokio::test]
+    async fn test_perplexity_with_and_without_versioning_paths() {
+        let providers = providers_lock(vec![build_provider("perplexity/sonar-pro", "sonar-pro")]);
+
+        // This is the path Plano should use for Perplexity (works).
+        let success_path = get_upstream_path(
+            &providers,
+            "perplexity/sonar-pro",
+            "/v1/chat/completions",
+            "sonar-pro",
+            false,
+        )
+        .await;
+        assert_eq!(success_path, "/chat/completions");
+
+        // This is the generic OpenAI default path; for Perplexity this would 404.
+        let fail_path = SupportedAPIsFromClient::OpenAIChatCompletions(OpenAIApi::ChatCompletions)
+            .target_endpoint_for_provider(
+                &hermesllm::ProviderId::OpenAI,
+                "/v1/chat/completions",
+                "sonar-pro",
+                false,
+                None,
+                false,
+            );
+        assert_eq!(fail_path, "/v1/chat/completions");
+        assert_ne!(success_path, fail_path);
+    }
+}