[router] Add Rerank Routing Logic in Regular Router (#10219)

sgl-router/tests/api_endpoints_test.rs

@@ -1752,3 +1752,332 @@ mod request_id_tests {
         ctx.shutdown().await;
     }
 }
+
+#[cfg(test)]
+mod rerank_tests {
+    use super::*;
+    // Note: RerankRequest and RerankResult are available for future use
+
+    #[tokio::test]
+    async fn test_rerank_success() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18105,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 0.0,
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        let payload = json!({
+            "query": "machine learning algorithms",
+            "documents": [
+                "Introduction to machine learning concepts",
+                "Deep learning neural networks tutorial"
+            ],
+            "model": "test-rerank-model",
+            "top_k": 2,
+            "return_documents": true,
+            "rid": "test-request-123"
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+
+        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
+            .await
+            .unwrap();
+        let body_json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        // Verify response structure
+        assert!(body_json.get("results").is_some());
+        assert!(body_json.get("model").is_some());
+        assert_eq!(body_json["model"], "test-rerank-model");
+
+        let results = body_json["results"].as_array().unwrap();
+        assert_eq!(results.len(), 2);
+
+        // Verify results are sorted by score (highest first)
+        assert!(results[0]["score"].as_f64().unwrap() >= results[1]["score"].as_f64().unwrap());
+
+        ctx.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn test_rerank_with_top_k() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18106,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 0.0,
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        let payload = json!({
+            "query": "test query",
+            "documents": [
+                "Document 1",
+                "Document 2",
+                "Document 3"
+            ],
+            "model": "test-model",
+            "top_k": 1,
+            "return_documents": true
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+
+        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
+            .await
+            .unwrap();
+        let body_json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        // Should only return top_k results
+        let results = body_json["results"].as_array().unwrap();
+        assert_eq!(results.len(), 1);
+
+        ctx.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn test_rerank_without_documents() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18107,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 0.0,
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        let payload = json!({
+            "query": "test query",
+            "documents": ["Document 1", "Document 2"],
+            "model": "test-model",
+            "return_documents": false
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+
+        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
+            .await
+            .unwrap();
+        let body_json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        // Documents should be null when return_documents is false
+        let results = body_json["results"].as_array().unwrap();
+        for result in results {
+            assert!(result.get("document").is_none());
+        }
+
+        ctx.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn test_rerank_worker_failure() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18108,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 1.0, // Always fail
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        let payload = json!({
+            "query": "test query",
+            "documents": ["Document 1"],
+            "model": "test-model"
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        // Should return the worker's error response
+        assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
+
+        ctx.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn test_v1_rerank_compatibility() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18110,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 0.0,
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        // Test V1 API format (simplified input)
+        let payload = json!({
+            "query": "machine learning algorithms",
+            "documents": [
+                "Introduction to machine learning concepts",
+                "Deep learning neural networks tutorial",
+                "Statistical learning theory basics"
+            ]
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/v1/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+
+        let body = axum::body::to_bytes(resp.into_body(), usize::MAX)
+            .await
+            .unwrap();
+        let body_json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        // Verify response structure
+        assert!(body_json.get("results").is_some());
+        assert!(body_json.get("model").is_some());
+
+        // V1 API should use default model name
+        assert_eq!(body_json["model"], "default");
+
+        let results = body_json["results"].as_array().unwrap();
+        assert_eq!(results.len(), 3); // All documents should be returned
+
+        // Verify results are sorted by score (highest first)
+        assert!(results[0]["score"].as_f64().unwrap() >= results[1]["score"].as_f64().unwrap());
+        assert!(results[1]["score"].as_f64().unwrap() >= results[2]["score"].as_f64().unwrap());
+
+        // V1 API should return documents by default
+        for result in results {
+            assert!(result.get("document").is_some());
+        }
+
+        ctx.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn test_rerank_invalid_request() {
+        let ctx = TestContext::new(vec![MockWorkerConfig {
+            port: 18111,
+            worker_type: WorkerType::Regular,
+            health_status: HealthStatus::Healthy,
+            response_delay_ms: 0,
+            fail_rate: 0.0,
+        }])
+        .await;
+
+        let app = ctx.create_app().await;
+
+        // Test empty query string (validation should fail)
+        let payload = json!({
+            "query": "",
+            "documents": ["Document 1", "Document 2"],
+            "model": "test-model"
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.clone().oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+
+        // Test query with only whitespace (validation should fail)
+        let payload = json!({
+            "query": "   ",
+            "documents": ["Document 1", "Document 2"],
+            "model": "test-model"
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.clone().oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+
+        // Test empty documents list (validation should fail)
+        let payload = json!({
+            "query": "test query",
+            "documents": [],
+            "model": "test-model"
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.clone().oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+
+        // Test invalid top_k (validation should fail)
+        let payload = json!({
+            "query": "test query",
+            "documents": ["Document 1", "Document 2"],
+            "model": "test-model",
+            "top_k": 0
+        });
+
+        let req = Request::builder()
+            .method("POST")
+            .uri("/rerank")
+            .header(CONTENT_TYPE, "application/json")
+            .body(Body::from(serde_json::to_string(&payload).unwrap()))
+            .unwrap();
+
+        let resp = app.oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+
+        ctx.shutdown().await;
+    }
+}

sgl-router/tests/common/mock_worker.rs

@@ -81,6 +81,7 @@ impl MockWorker {
             .route("/generate", post(generate_handler))
             .route("/v1/chat/completions", post(chat_completions_handler))
             .route("/v1/completions", post(completions_handler))
+            .route("/v1/rerank", post(rerank_handler))
             .route("/v1/responses", post(responses_handler))
             .route("/flush_cache", post(flush_cache_handler))
             .route("/v1/models", get(v1_models_handler))
@@ -687,6 +688,56 @@ async fn v1_models_handler(State(config): State<Arc<RwLock<MockWorkerConfig>>>)
     .into_response()
 }
 
+async fn rerank_handler(
+    State(config): State<Arc<RwLock<MockWorkerConfig>>>,
+    Json(payload): Json<serde_json::Value>,
+) -> impl IntoResponse {
+    let config = config.read().await;
+
+    // Simulate response delay
+    if config.response_delay_ms > 0 {
+        tokio::time::sleep(tokio::time::Duration::from_millis(config.response_delay_ms)).await;
+    }
+
+    // Simulate failure rate
+    if rand::random::<f32>() < config.fail_rate {
+        return (StatusCode::INTERNAL_SERVER_ERROR, "Simulated failure").into_response();
+    }
+
+    // Extract documents from the request to create mock results
+    let empty_vec = vec![];
+    let documents = payload
+        .get("documents")
+        .and_then(|d| d.as_array())
+        .unwrap_or(&empty_vec);
+
+    // Create mock rerank results with scores based on document index
+    let mut mock_results = Vec::new();
+    for (i, doc) in documents.iter().enumerate() {
+        let score = 0.95 - (i as f32 * 0.1); // Decreasing scores
+        let result = serde_json::json!({
+            "score": score,
+            "document": doc.as_str().unwrap_or(""),
+            "index": i,
+            "meta_info": {
+                "confidence": if score > 0.9 { "high" } else { "medium" }
+            }
+        });
+        mock_results.push(result);
+    }
+
+    // Sort by score (highest first) to simulate proper ranking
+    mock_results.sort_by(|a, b| {
+        b["score"]
+            .as_f64()
+            .unwrap()
+            .partial_cmp(&a["score"].as_f64().unwrap())
+            .unwrap()
+    });
+
+    (StatusCode::OK, Json(mock_results)).into_response()
+}
+
 impl Default for MockWorkerConfig {
     fn default() -> Self {
         Self {