Addressing comments & fixing build

Author: schmidt-sebastian

packages/firestore/src/api/database.ts

@@ -456,7 +456,7 @@ export class Firestore implements firestore.Firestore, FirebaseService {
     }
   }
 
-  /** Creates a new AsyncQueue. Can be overwritten to provide a custom queue. */
+  /** Creates a new AsyncQueue. Can be overridden to provide a custom queue. */
   protected initializeAsyncQueue(): AsyncQueue {
     return new AsyncQueue();
   }

packages/firestore/src/remote/persistent_stream.ts

@@ -255,7 +255,10 @@ export abstract class PersistentStream<
         return this.handleIdleCloseTimer();
       }, IDLE_TIMEOUT_MS)
       .catch((err: FirestoreError) => {
-        // We ignore Promise rejections for cancelled idle checks.
+        // When the AsyncQueue gets drained during a shutdown, pending Promises
+        // (including these idle checks) will get rejected. We special-case
+        // these cancelled idle checks to make sure that these specific Promise
+        // rejections are not considered unhandled.
         assert(
           err.code === Code.CANCELLED,
           `Received unexpected error in idle timeout closure. Expected CANCELLED, but was: ${err}`
@@ -287,12 +290,10 @@ export abstract class PersistentStream<
   /**
    * Closes the stream and cleans up as necessary:
    *
-   * <ul>
-   *   <li>closes the underlying GRPC stream;
-   *   <li>calls the onClose handler with the given 'error';
-   *   <li>sets internal stream state to 'finalState';
-   *   <li>adjusts the backoff timer based on the error
-   * </ul>
+   * * closes the underlying GRPC stream;
+   * * calls the onClose handler with the given 'error';
+   * * sets internal stream state to 'finalState';
+   * * adjusts the backoff timer based on the error
    *
    * A new stream can be opened by calling `start` unless `finalState` is set to
    * `PersistentStreamState.Stopped`.

packages/firestore/src/util/async_queue.ts

@@ -50,7 +50,7 @@ export class AsyncQueue {
 
     if ((delay || 0) > 0) {
       const deferred = new Deferred<T>();
-      let handle = window.setTimeout(() => {
+      const handle = window.setTimeout(() => {
         this.scheduleInternal(() => {
           return op().then(result => {
             deferred.resolve(result);
@@ -103,7 +103,7 @@ export class AsyncQueue {
     this.delayedOperations.forEach((deferred, handle) => {
       window.clearTimeout(handle);
       deferred.reject(
-        new FirestoreError(Code.CANCELLED, 'Cancelled during queue drain')
+        new FirestoreError(Code.CANCELLED, 'Operation cancelled by shutdown')
       );
     });
     this.delayedOperations.clear();

packages/firestore/test/integration/util/helpers.ts

@@ -16,6 +16,8 @@
 
 import * as firestore from 'firestore';
 
+import { FirebaseApp } from '@firebase/app';
+
 import { DatabaseId, DatabaseInfo } from '../../../src/core/database_info';
 import { Datastore } from '../../../src/remote/datastore';
 
@@ -24,7 +26,6 @@ import { EmptyCredentialsProvider } from '../../../src/api/credentials';
 import { PlatformSupport } from '../../../src/platform/platform';
 import { AsyncQueue } from '../../../src/util/async_queue';
 import { Firestore, FirestoreDatabase } from '../../../src/api/database';
-import { FirebaseApp } from '../../../../app/index';
 import { TestQueue } from './test_queue';
 
 // tslint:disable-next-line:no-any __karma__ is an untyped global