Fix setting timeout; add multiple flush test

Author: mikechu-optimizely

packages/optimizely-sdk/lib/plugins/odp/odp_event_manager.ts

@@ -24,7 +24,7 @@ import { RestApiManager } from './rest_api_manager';
 const MAX_RETRIES = 3;
 const DEFAULT_BATCH_SIZE = 10;
 const DEFAULT_FLUSH_INTERVAL_MSECS = 1000;
-const DEFAULT_BROWSER_QUEUE_SIZE = 10;
+const DEFAULT_BROWSER_QUEUE_SIZE = 100;
 const DEFAULT_SERVER_QUEUE_SIZE = 10000;
 
 /**
@@ -255,19 +255,15 @@ export class OdpEventManager implements IOdpEventManager {
     }
 
     // Flush interval occurred & queue has items
-    if (shouldFlush && this.queueContainsItems()) {
+    if (shouldFlush) {
       // clear the queue completely
       this.clearCurrentTimeout();
 
       this.state = STATE.PROCESSING;
 
       while (this.queueContainsItems()) {
-        this.makeAndSendBatch();
+        this.makeAndSend1Batch();
       }
-
-      this.state = STATE.RUNNING;
-
-      this.setNewTimeout();
     }
     // Check if queue has a full batch available
     else if (this.queueHasBatches()) {
@@ -276,13 +272,12 @@ export class OdpEventManager implements IOdpEventManager {
       this.state = STATE.PROCESSING;
 
       while (this.queueHasBatches()) {
-        this.makeAndSendBatch();
+        this.makeAndSend1Batch();
       }
-
-      this.state = STATE.RUNNING;
-
-      this.setNewTimeout();
     }
+
+    this.state = STATE.RUNNING;
+    this.setNewTimeout();
   }
 
   /**
@@ -309,9 +304,10 @@ export class OdpEventManager implements IOdpEventManager {
    * Make a batch and send it to ODP
    * @private
    */
-  private makeAndSendBatch(): void {
+  private makeAndSend1Batch(): void {
     const batch = new Array<OdpEvent>();
 
+    // remove a batch from the queue
     for (let count = 0; count < this.batchSize; count += 1) {
       const event = this.queue.shift();
       if (event) {
@@ -322,6 +318,7 @@ export class OdpEventManager implements IOdpEventManager {
     }
 
     if (batch.length > 0) {
+      // put sending the event on another event loop
       setTimeout(async () => {
         let shouldRetry: boolean;
         let attemptNumber = 0;

packages/optimizely-sdk/tests/odpEventManager.spec.ts

@@ -16,7 +16,7 @@
 
 import { OdpConfig } from '../lib/plugins/odp/odp_config';
 import { OdpEventManager, STATE } from '../lib/plugins/odp/odp_event_manager';
-import { anything, capture, instance, mock, resetCalls, verify, when } from 'ts-mockito';
+import { anything, capture, instance, mock, resetCalls, spy, verify, when } from 'ts-mockito';
 import { RestApiManager } from '../lib/plugins/odp/rest_api_manager';
 import { LogHandler, LogLevel } from '../lib/modules/logging';
 import { OdpEvent } from '../lib/plugins/odp/odp_event';
@@ -204,6 +204,20 @@ describe('OdpEventManager', () => {
     expect(eventData.get('key-4')).toEqual(processedEventData.get('key-4'));
   });
 
+  it('should attempt to flush an empty queue at flush intervals', async () => {
+    const eventManager = new OdpEventManager({
+      odpConfig, apiManager, logger, clientEngine, clientVersion,
+      flushInterval: 100,
+    });
+    const spiedEventManager = spy(eventManager);
+
+    eventManager.start();
+    // do not add events to the queue, but allow for...
+    await pause(400); // at least 3 flush intervals executions (giving a little longer)
+
+    verify(spiedEventManager['processQueue'](anything())).atLeast(3);
+  });
+
   it('should dispatch events in correct number of batches', async () => {
     when(mockApiManager.sendEvents(anything(), anything(), anything())).thenResolve(false);
     const apiManager = instance(mockApiManager);