fix(llmobs): send batches of span events (#5493)

* batch span events

* try to fix test

---------

Co-authored-by: lievan <evan.li@datadoqhq.com>

Author: 2 people

packages/dd-trace/src/llmobs/writers/spans/base.js

@@ -41,12 +41,12 @@ class LLMObsSpanWriter extends BaseWriter {
   }
 
   makePayload (events) {
-    return {
+    return events.map(event => ({
       '_dd.stage': 'raw',
       '_dd.tracer_version': tracerVersion,
       event_type: this._eventType,
-      spans: events
-    }
+      spans: [event]
+    }))
   }
 
   _truncateSpanEvent (event) {

packages/dd-trace/test/llmobs/sdk/typescript/index.spec.js

@@ -38,7 +38,7 @@ const testCases = [
     file: 'index',
     setup: (agent, results = {}) => {
       const llmobsRes = agent.assertLlmObsPayloadReceived(({ payload }) => {
-        results.llmobsSpans = payload.spans
+        results.llmobsSpans = payload.flatMap(item => item.spans)
       })
 
       const apmRes = agent.assertMessageReceived(({ payload }) => {

packages/dd-trace/test/llmobs/writers/spans/base.spec.js

@@ -92,8 +92,8 @@ describe('LLMObsSpanWriter', () => {
 
     const payload = writer.makePayload(events)
 
-    expect(payload['_dd.stage']).to.equal('raw')
-    expect(payload.event_type).to.equal('span')
-    expect(payload.spans).to.deep.equal(events)
+    expect(payload[0]['_dd.stage']).to.equal('raw')
+    expect(payload[0].event_type).to.equal('span')
+    expect(payload[0].spans).to.deep.equal(events)
   })
 })