fix(llmobs): avoid stale version on latest dataset pulls

Author: mehulsonowal

packages/dd-trace/src/llmobs/experiments/index.js

@@ -98,7 +98,8 @@ class Experiments {
             if (dataset.name() === name) {
               pulledDataset = dataset
               latestVersion = dataset.latestVersion()
-              datasetVersion = version ?? latestVersion
+              // Let an unversioned records request resolve the latest snapshot. Dataset metadata can lag record
+              // ingestion.
               break
             }
           }
@@ -158,7 +159,7 @@ class Experiments {
       pulledDataset.id(),
       projectId,
       records,
-      datasetVersion,
+      datasetVersion ?? latestVersion,
       latestVersion,
       filterTags
     )

packages/dd-trace/test/llmobs/experiments/index.spec.js

@@ -300,7 +300,7 @@ describe('LLMObs Experiments facade', () => {
       assert.deepEqual(listDatasetRecords.secondCall.args, ['proj', 'ds', { cursor: 'next-page', tags: [], version: 2 }])
     })
 
-    it('uses the latest dataset version when no version is requested', async () => {
+    it('uses the latest records when no version is requested', async () => {
       const { listDatasetRecords } = stubPullDatasetClient({
         datasets: [datasetResource({ name: 'remote-dataset', latestVersion: 5 })],
         pages: [{ records: [], after: '' }],
@@ -309,7 +309,7 @@ describe('LLMObs Experiments facade', () => {
       const dataset = await createExperiments(enabledConfig()).pullDataset('remote-dataset', { maxWaitMs: 0 })
 
       assert.equal(dataset.version(), 5)
-      assert.deepEqual(listDatasetRecords.firstCall.args, ['proj', 'ds', { cursor: '', tags: [], version: 5 }])
+      assert.deepEqual(listDatasetRecords.firstCall.args, ['proj', 'ds', { cursor: '', tags: [], version: null }])
     })
 
     it('surfaces list failures from the backend client', async () => {