fix: traceId conversion using jsonValue instead of regular value

Author: daniel-mohedano

dd-trace-core/src/main/java/datadog/trace/common/writer/FileBasedPayloadDispatcher.java

@@ -243,14 +243,16 @@ private String serializeTestEvent(CoreSpan<?> span) {
     w.name("content");
     w.beginObject();
 
+    // trace/span/parent ids are unsigned 64-bit integers; emit as raw JSON numbers
+    // (value(long) would reinterpret ids >= 2^63 as negative signed longs).
     if (traceId != null) {
-      w.name("trace_id").value(Long.toUnsignedString(traceId));
+      w.name("trace_id").jsonValue(Long.toUnsignedString(traceId));
     }
     if (spanId != null) {
-      w.name("span_id").value(Long.toUnsignedString(spanId));
+      w.name("span_id").jsonValue(Long.toUnsignedString(spanId));
     }
     if (parentId != null) {
-      w.name("parent_id").value(Long.toUnsignedString(parentId));
+      w.name("parent_id").jsonValue(Long.toUnsignedString(parentId));
     }
     if (testSessionId != null) {
       w.name(Tags.TEST_SESSION_ID).value(testSessionId.toLong());

dd-trace-core/src/test/java/datadog/trace/common/writer/FileBasedPayloadDispatcherTest.java

@@ -102,6 +102,10 @@ void citestcycleFlushWritesEnvelopeWithVersionMetadataAndEvents(@TempDir Path ou
     assertEquals(456L, content.get(Tags.TEST_MODULE_ID).asLong());
     assertEquals(789L, content.get(Tags.TEST_SUITE_ID).asLong());
     assertEquals("corr-1", content.get(Tags.ITR_CORRELATION_ID).asText());
+    // trace/span/parent ids must be JSON numbers (backend schema rejects strings)
+    assertTrue(content.get("trace_id").isNumber(), "trace_id should be a JSON number");
+    assertTrue(content.get("span_id").isNumber(), "span_id should be a JSON number");
+    assertTrue(content.get("parent_id").isNumber(), "parent_id should be a JSON number");
   }
 
   @Test