Polish ex_data variable initialization

Author: estcarisimo

qlog/src/testing/event_tests.rs

@@ -173,11 +173,10 @@ fn packet_header() {
 #[test]
 fn metrics_updated_with_ex_data() {
     // Test that ex_data fields are flattened into the same object
-    let mut ex_data = ExData::new();
-    ex_data.insert(
+    let mut ex_data = ExData::from([(
         "delivery_rate".to_string(),
         serde_json::json!(DELIVERY_RATE),
-    );
+    )]);
 
     let metrics = MetricsUpdated {
         min_rtt: Some(MIN_RTT),
@@ -202,8 +201,11 @@ fn metrics_updated_ex_data_collision() {
     // Test collision: same field set via struct AND ex_data.
     // With serde's preserve_order feature and ex_data at the top of the
     // struct, standard fields are serialized last and take precedence.
-    let mut ex_data = ExData::new();
-    ex_data.insert("min_rtt".to_string(), serde_json::json!(COLLISION_VALUE));
+
+    let mut ex_data = ExData::from([(
+        "min_rtt".to_string(),
+        serde_json::json!(COLLISION_VALUE),
+    )]);
 
     let metrics = MetricsUpdated {
         min_rtt: Some(MIN_RTT), // struct field value
@@ -221,11 +223,10 @@ fn metrics_updated_ex_data_collision() {
 #[test]
 fn metrics_updated_round_trip() {
     // Test serialization -> deserialization round-trip
-    let mut ex_data = ExData::new();
-    ex_data.insert(
+    let ex_data = ExData::from([(
         "delivery_rate".to_string(),
         serde_json::json!(DELIVERY_RATE),
-    );
+    )]);
 
     let original = MetricsUpdated {
         min_rtt: Some(MIN_RTT),