Update test and add a TODO

Author: tejasd

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/GaugeManager.java

@@ -221,8 +221,6 @@ public void stopCollectingGauges() {
 
     // This is needed, otherwise the Runnable might use a stale value.
 
-    // AQS is guaranteed to be available when stopping gauge collection.
-    final String sessionIdForScheduledTask = session.aqsSessionId();
     final ApplicationProcessState applicationProcessStateForScheduledTask = applicationProcessState;
 
     cpuGaugeCollector.get().stopCollecting();
@@ -232,6 +230,14 @@ public void stopCollectingGauges() {
       gaugeManagerDataCollectionJob.cancel(false);
     }
 
+
+    final String sessionIdForScheduledTask = session.aqsSessionId();
+    this.session = null;
+    if (sessionIdForScheduledTask.equals(Constants.UNDEFINED_AQS_ID)) {
+      // TODO(b/394127311): Use DebugEnforcementCheck.
+      return;
+    }
+
     // Flush any data that was collected for this session one last time.
     @SuppressWarnings("FutureReturnValueIgnored")
     ScheduledFuture<?> unusedFuture =
@@ -244,7 +250,6 @@ public void stopCollectingGauges() {
                 TIME_TO_WAIT_BEFORE_FLUSHING_GAUGES_QUEUE_MS,
                 TimeUnit.MILLISECONDS);
 
-    this.session = null;
   }
 
   /**
@@ -270,7 +275,6 @@ private void syncFlush(String sessionId, ApplicationProcessState appState) {
 
     // Adding Session ID info.
     gaugeMetricBuilder.setSessionId(sessionId);
-
     transportManager.log(gaugeMetricBuilder.build(), appState);
   }
 

firebase-perf/src/test/java/com/google/firebase/perf/session/gauges/GaugeManagerTest.java

@@ -451,13 +451,19 @@ public void testGaugeManagerDoesNotClearTheQueueUnlessUpdated() {
     assertThat(fakeCpuGaugeCollector.cpuMetricReadings).isNotEmpty();
     assertThat(fakeMemoryGaugeCollector.memoryMetricReadings).isNotEmpty();
 
+
+    fakeSession.setAQSId(new SessionSubscriber.SessionDetails("aqsSessionId"));
     testGaugeManager.updateGaugeCollection(ApplicationProcessState.FOREGROUND);
 
     fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
     assertThat(fakeCpuGaugeCollector.cpuMetricReadings).isEmpty();
     assertThat(fakeMemoryGaugeCollector.memoryMetricReadings).isEmpty();
+
+    assertThat(fakeScheduledExecutorService.isEmpty()).isFalse();
   }
 
+
+
   @Test
   public void testLogGaugeMetadataSendDataToTransport() {
     when(fakeGaugeMetadataManager.getDeviceRamSizeKb()).thenReturn(2000);