fix: Fixed api.getTraceMetadata to handle when there is an active transaction but not active segment (#2944)

Author: bizob2828

api.js

@@ -1537,18 +1537,24 @@ API.prototype.getTraceMetadata = function getTraceMetadata() {
     NAMES.SUPPORTABILITY.API + '/getTraceMetadata'
   )
   metric.incrementCallCount()
-
   const metadata = {}
 
-  const segment = this.agent.tracer.getSegment()
+  if (this.agent.config.distributed_tracing.enabled === false) {
+    return metadata
+  }
+
   const transaction = this.agent.tracer.getTransaction()
-  if (!(segment || transaction)) {
+  if (!transaction) {
     logger.debug('No transaction found when calling API#getTraceMetadata')
-  } else if (!this.agent.config.distributed_tracing.enabled) {
-    logger.debug('Distributed tracing disabled when calling API#getTraceMetadata')
   } else {
     metadata.traceId = transaction.traceId
+  }
+
+  const segment = this.agent.tracer.getSegment()
 
+  if (!segment) {
+    logger.debug('No segment found when calling API#getTraceMetadata')
+  } else {
     const spanId = segment.getSpanId()
     if (spanId) {
       metadata.spanId = spanId

test/unit/api/api-get-trace-metadata.test.js

@@ -71,4 +71,22 @@ test('Agent API - trace metadata', async (t) => {
       end()
     })
   })
+
+  await t.test('should not include transaction when not in active transaction', (t) => {
+    const { api } = t.nr
+    const metadata = api.getTraceMetadata()
+    assert.deepEqual(metadata, {})
+  })
+
+  await t.test('should not include spanId when in active active transaction but not active segment', (t, end) => {
+    const { api, agent } = t.nr
+
+    helper.runInTransaction(agent, function (txn) {
+      agent.tracer.setSegment({ segment: null })
+      const metadata = api.getTraceMetadata()
+      assert.equal(metadata.traceId, txn.traceId)
+      assert.ok(!metadata.spanId)
+      end()
+    })
+  })
 })