add test test_get_traces_from_request_body_with_span_links

trace-utils/src/trace_utils.rs

@@ -902,6 +902,66 @@ mod tests {
         }
     }
 
+    #[tokio::test]
+    async fn test_get_traces_from_request_body_with_span_links() {
+        let trace_input = json!([[{
+        "service": "test-service",
+        "name": "test-name",
+        "resource": "test-resource",
+        "trace_id": 111,
+        "span_id": 222,
+        "parent_id": 333,
+        "start": 1,
+        "duration": 5,
+        "error": 0,
+        "meta": {},
+        "metrics": {},
+        "span_links": [{
+            "trace_id": 999,
+            "span_id": 888,
+            "trace_id_high": 777,
+            "attributes": {"key": "value"},
+            "tracestate": "vendor=value"
+            // flags field intentionally omitted
+        }]
+    }]]);
+
+        let expected_output = vec![vec![pb::Span {
+            service: "test-service".to_string(),
+            name: "test-name".to_string(),
+            resource: "test-resource".to_string(),
+            trace_id: 111,
+            span_id: 222,
+            parent_id: 333,
+            start: 1,
+            duration: 5,
+            error: 0,
+            meta: HashMap::new(),
+            metrics: HashMap::new(),
+            meta_struct: HashMap::new(),
+            r#type: String::new(),
+            span_links: vec![pb::SpanLink {
+                trace_id: 999,
+                span_id: 888,
+                trace_id_high: 777,
+                attributes: HashMap::from([
+                    ("key".to_string(), "value".to_string())
+                ]),
+                tracestate: "vendor=value".to_string(),
+                flags: 0, // Should default to 0 when omitted
+            }],
+        }]];
+
+        let bytes = rmp_serde::to_vec(&trace_input).unwrap();
+        let request = Request::builder()
+            .body(hyper::body::Body::from(bytes))
+            .unwrap();
+
+        let res = get_traces_from_request_body(request.into_body()).await;
+        assert!(res.is_ok(), "Failed to deserialize: {:?}", res);
+        assert_eq!(res.unwrap().1, expected_output);
+    }
+
     #[test]
     fn test_get_root_span_index_from_complete_trace() {
         let trace = vec![