From 8dd846dd8de1cb306133ad9c2721782a426be60e Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Wed, 24 Jul 2019 14:45:31 -0400
Subject: [PATCH 01/10] pending firebaseApp change

---
 packages/firebase/index.d.ts                  |   5 +-
 packages/firestore-types/index.d.ts           |   5 +-
 packages/firestore/src/api/database.ts        | 235 ++++++++++--------
 .../firestore/src/core/firestore_client.ts    |  53 ++--
 packages/firestore/src/util/async_queue.ts    |  64 ++++-
 .../test/integration/api/database.test.ts     |  27 +-
 .../test/unit/util/async_queue.test.ts        |  22 ++
 7 files changed, 275 insertions(+), 136 deletions(-)

diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 28b43b2a311..0524ac36de8 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -6225,7 +6225,10 @@ declare namespace firebase.firestore {
     /**
      * @hidden
      */
-    INTERNAL: { delete: () => Promise<void> };
+    INTERNAL: { 
+      delete: () => Promise<void>
+      isShutdown: () => boolean
+    };
   }
 
   /**
diff --git a/packages/firestore-types/index.d.ts b/packages/firestore-types/index.d.ts
index c96fa5925dc..c783db59454 100644
--- a/packages/firestore-types/index.d.ts
+++ b/packages/firestore-types/index.d.ts
@@ -276,7 +276,10 @@ export class FirebaseFirestore {
    */
   disableNetwork(): Promise<void>;
 
-  INTERNAL: { delete: () => Promise<void> };
+  INTERNAL: { 
+    delete: () => Promise<void>
+    isShutdown: () => boolean
+  };
 }
 
 /**
diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index 161435d773c..4c60c0a9c11 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -353,7 +353,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         '"persistence" is now specified with a separate call to ' +
-          'firestore.enablePersistence().'
+        'firestore.enablePersistence().'
       );
     }
 
@@ -362,8 +362,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and its settings can no longer ' +
-          'be changed. You can only call settings() before calling any other ' +
-          'methods on a Firestore object.'
+        'be changed. You can only call settings() before calling any other ' +
+        'methods on a Firestore object.'
       );
     }
 
@@ -390,8 +390,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and persistence can no longer ' +
-          'be enabled. You can only call enablePersistence() before calling ' +
-          'any other methods on a Firestore object.'
+        'be enabled. You can only call enablePersistence() before calling ' +
+        'any other methods on a Firestore object.'
       );
     }
 
@@ -401,9 +401,9 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       if (settings.experimentalTabSynchronization !== undefined) {
         log.error(
           "The 'experimentalTabSynchronization' setting has been renamed to " +
-            "'synchronizeTabs'. In a future release, the setting will be removed " +
-            'and it is recommended that you update your ' +
-            "firestore.enablePersistence() call to use 'synchronizeTabs'."
+          "'synchronizeTabs'. In a future release, the setting will be removed " +
+          'and it is recommended that you update your ' +
+          "firestore.enablePersistence() call to use 'synchronizeTabs'."
         );
       }
       synchronizeTabs = objUtils.defaulted(
@@ -427,7 +427,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       this.makeDatabaseInfo()
     );
     const deferred = new Deferred<void>();
-    this._queue.enqueueAndForget(async () => {
+    this._queue.enqueueAndForgetEvenAfterShutdown(async () => {
       try {
         if (
           this._firestoreClient !== undefined &&
@@ -486,8 +486,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Document reference is for database ' +
-              `${otherDb.projectId}/${otherDb.database} but should be ` +
-              `for database ${thisDb.projectId}/${thisDb.database}`
+            `${otherDb.projectId}/${otherDb.database} but should be ` +
+            `for database ${thisDb.projectId}/${thisDb.database}`
           );
         }
         return new DocumentKeyReference(this._config.databaseId, value._key);
@@ -531,18 +531,49 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         "Firestore was not initialized using the Firebase SDK. 'app' is " +
-          'not available'
+        'not available'
       );
     }
     return this._config.firebaseApp;
   }
 
+  /**
+   * Shuts down this FirebaseFirestore instance.
+   *
+   * After shutdown only the `clearPersistence()` method may be used. Any other method
+   * will throw an `FirestoreError`.
+   *
+   * To restart after shutdown, simply create a new instance of FirebaseFirestore with 
+   * `Firebase.firestore()`.
+   *
+   * Shutdown does not cancel any pending writes and any promises that are awaiting a response from
+   * the server will be resolved with `undefined`. The next time you start this instance, it will resume
+   * attempting to send these writes to the server.
+   *
+   * Note: Under normal circumstances, calling `shutdown()` is not required. This
+   * method is useful only when you want to force this instance to release all of its resources or
+   * in combination with `clearPersistence()` to ensure that all local state is destroyed
+   * between test runs.
+   *
+   * @return A promise that is resolved when the instance has been successfully shut down.
+   */
+  // TODO(b/135755126): make this public.
+  private shutdown(): Promise<void> {
+    return this.INTERNAL.delete();
+  }
+
   INTERNAL = {
+    // TODO(b/135755126): Make this public
     delete: async (): Promise<void> => {
       // The client must be initalized to ensure that all subsequent API usage
       // throws an exception.
       this.ensureClientConfigured();
       await this._firestoreClient!.shutdown();
+    },
+
+    // TODO(b/135755126): make this public.
+    isShutdown: (): boolean => {
+      return this._firestoreClient!.clientShutdown;
     }
   };
 
@@ -572,7 +603,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid collection ID '${collectionId}' passed to function ` +
-          `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
+        `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
       );
     }
     this.ensureClientConfigured();
@@ -648,7 +679,7 @@ export class Transaction implements firestore.Transaction {
   constructor(
     private _firestore: Firestore,
     private _transaction: InternalTransaction
-  ) {}
+  ) { }
 
   get(
     documentRef: firestore.DocumentReference
@@ -705,10 +736,10 @@ export class Transaction implements firestore.Transaction {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-            'Transaction.set',
-            value,
-            options.mergeFields
-          )
+          'Transaction.set',
+          value,
+          options.mergeFields
+        )
         : this._firestore._dataConverter.parseSetData('Transaction.set', value);
     this._transaction.set(ref._key, parsed);
     return this;
@@ -782,7 +813,7 @@ export class WriteBatch implements firestore.WriteBatch {
   private _mutations = [] as Mutation[];
   private _committed = false;
 
-  constructor(private _firestore: Firestore) {}
+  constructor(private _firestore: Firestore) { }
 
   set(
     documentRef: firestore.DocumentReference,
@@ -800,10 +831,10 @@ export class WriteBatch implements firestore.WriteBatch {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-            'WriteBatch.set',
-            value,
-            options.mergeFields
-          )
+          'WriteBatch.set',
+          value,
+          options.mergeFields
+        )
         : this._firestore._dataConverter.parseSetData('WriteBatch.set', value);
     this._mutations = this._mutations.concat(
       parsed.toMutations(ref._key, Precondition.NONE)
@@ -894,7 +925,7 @@ export class WriteBatch implements firestore.WriteBatch {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'A write batch can no longer be used after commit() ' +
-          'has been called.'
+        'has been called.'
       );
     }
   }
@@ -915,8 +946,8 @@ export class DocumentReference implements firestore.DocumentReference {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid document reference. Document ' +
-          'references must have an even number of segments, but ' +
-          `${path.canonicalString()} has ${path.length}`
+        'references must have an even number of segments, but ' +
+        `${path.canonicalString()} has ${path.length}`
       );
     }
     return new DocumentReference(new DocumentKey(path), firestore);
@@ -969,14 +1000,14 @@ export class DocumentReference implements firestore.DocumentReference {
     const parsed =
       options.merge || options.mergeFields
         ? this.firestore._dataConverter.parseMergeData(
-            'DocumentReference.set',
-            value,
-            options.mergeFields
-          )
+          'DocumentReference.set',
+          value,
+          options.mergeFields
+        )
         : this.firestore._dataConverter.parseSetData(
-            'DocumentReference.set',
-            value
-          );
+          'DocumentReference.set',
+          value
+        );
     return this._firestoreClient.write(
       parsed.toMutations(this._key, Precondition.NONE)
     );
@@ -1020,7 +1051,7 @@ export class DocumentReference implements firestore.DocumentReference {
   }
 
   delete(): Promise<void> {
-    validateExactNumberOfArgs('DocumentReference.delete', arguments, 0);
+    validateExactNumberOfArgs('FirebaseFirestore.shutdown', arguments, 0);
     return this._firestoreClient.write([
       new DeleteMutation(this._key, Precondition.NONE)
     ]);
@@ -1220,9 +1251,9 @@ export class DocumentReference implements firestore.DocumentReference {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get document from server. (However, this ' +
-                  'document does exist in the local cache. Run again ' +
-                  'without setting source to "server" to ' +
-                  'retrieve the cached document.)'
+                'document does exist in the local cache. Run again ' +
+                'without setting source to "server" to ' +
+                'retrieve the cached document.)'
               )
             );
           } else {
@@ -1239,7 +1270,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
   constructor(
     readonly hasPendingWrites: boolean,
     readonly fromCache: boolean
-  ) {}
+  ) { }
 
   isEqual(other: firestore.SnapshotMetadata): boolean {
     return (
@@ -1253,7 +1284,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
  * Options interface that can be provided to configure the deserialization of
  * DocumentSnapshots.
  */
-export interface SnapshotOptions extends firestore.SnapshotOptions {}
+export interface SnapshotOptions extends firestore.SnapshotOptions { }
 
 export class DocumentSnapshot implements firestore.DocumentSnapshot {
   constructor(
@@ -1262,7 +1293,7 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     public _document: Document | null,
     private _fromCache: boolean,
     private _hasPendingWrites: boolean
-  ) {}
+  ) { }
 
   data(
     options?: firestore.SnapshotOptions
@@ -1272,12 +1303,12 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     return !this._document
       ? undefined
       : this.convertObject(
-          this._document.data,
-          FieldValueOptions.fromSnapshotOptions(
-            options,
-            this._firestore._areTimestampsInSnapshotsEnabled()
-          )
-        );
+        this._document.data,
+        FieldValueOptions.fromSnapshotOptions(
+          options,
+          this._firestore._areTimestampsInSnapshotsEnabled()
+        )
+      );
   }
 
   get(
@@ -1356,11 +1387,11 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
         // TODO(b/64130202): Somehow support foreign references.
         log.error(
           `Document ${this._key.path} contains a document ` +
-            `reference within a different database (` +
-            `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
-            `supported. It will be treated as a reference in the current ` +
-            `database (${database.projectId}/${database.database}) ` +
-            `instead.`
+          `reference within a different database (` +
+          `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
+          `supported. It will be treated as a reference in the current ` +
+          `database (${database.projectId}/${database.database}) ` +
+          `instead.`
         );
       }
       return new DocumentReference(key, this._firestore);
@@ -1392,7 +1423,7 @@ export class QueryDocumentSnapshot extends DocumentSnapshot
 }
 
 export class Query implements firestore.Query {
-  constructor(public _query: InternalQuery, readonly firestore: Firestore) {}
+  constructor(public _query: InternalQuery, readonly firestore: Firestore) { }
 
   where(
     field: string | ExternalFieldPath,
@@ -1423,7 +1454,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid Query. You can't perform '${operator.toString()}' ` +
-            'queries on FieldPath.documentId().'
+          'queries on FieldPath.documentId().'
         );
       } else if (operator === Operator.IN) {
         this.validateDisjunctiveFilterElements(value, operator);
@@ -1472,21 +1503,21 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Function Query.orderBy() has unknown direction '${directionStr}', ` +
-          `expected 'asc' or 'desc'.`
+        `expected 'asc' or 'desc'.`
       );
     }
     if (this._query.startAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.startAt() or ' +
-          'Query.startAfter() before calling Query.orderBy().'
+        'Query.startAfter() before calling Query.orderBy().'
       );
     }
     if (this._query.endAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.endAt() or ' +
-          'Query.endBefore() before calling Query.orderBy().'
+        'Query.endBefore() before calling Query.orderBy().'
       );
     }
     const fieldPath = fieldPathFromArgument('Query.orderBy', field);
@@ -1502,7 +1533,7 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. Query limit (${n}) is invalid. Limit must be ` +
-          'positive.'
+        'positive.'
       );
     }
     return new Query(this._query.withLimit(n), this.firestore);
@@ -1593,7 +1624,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.NOT_FOUND,
           `Can't use a DocumentSnapshot that doesn't exist for ` +
-            `${methodName}().`
+          `${methodName}().`
         );
       }
       return this.boundFromDocument(methodName, snap._document!, before);
@@ -1637,10 +1668,10 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. You are trying to start or end a query using a ' +
-              'document for which the field "' +
-              orderBy.field +
-              '" is an uncommitted server timestamp. (Since the value of ' +
-              'this field is unknown, you cannot start/end a query with it.)'
+            'document for which the field "' +
+            orderBy.field +
+            '" is an uncommitted server timestamp. (Since the value of ' +
+            'this field is unknown, you cannot start/end a query with it.)'
           );
         } else if (value !== null) {
           components.push(value);
@@ -1649,8 +1680,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. You are trying to start or end a query using a ` +
-              `document for which the field '${field}' (used as the ` +
-              `orderBy) does not exist.`
+            `document for which the field '${field}' (used as the ` +
+            `orderBy) does not exist.`
           );
         }
       }
@@ -1672,8 +1703,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Too many arguments provided to ${methodName}(). ` +
-          `The number of arguments must be less than or equal to the ` +
-          `number of Query.orderBy() clauses`
+        `The number of arguments must be less than or equal to the ` +
+        `number of Query.orderBy() clauses`
       );
     }
 
@@ -1686,7 +1717,7 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. Expected a string for document ID in ` +
-              `${methodName}(), but got a ${typeof rawValue}`
+            `${methodName}(), but got a ${typeof rawValue}`
           );
         }
         if (
@@ -1696,8 +1727,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection and ordering by FieldPath.documentId(), ` +
-              `the value passed to ${methodName}() must be a plain document ID, but ` +
-              `'${rawValue}' contains a slash.`
+            `the value passed to ${methodName}() must be a plain document ID, but ` +
+            `'${rawValue}' contains a slash.`
           );
         }
         const path = this._query.path.child(ResourcePath.fromString(rawValue));
@@ -1705,9 +1736,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection group and ordering by ` +
-              `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
-              `valid document path, but '${path}' is not because it contains an odd number ` +
-              `of segments.`
+            `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
+            `valid document path, but '${path}' is not because it contains an odd number ` +
+            `of segments.`
           );
         }
         const key = new DocumentKey(path);
@@ -1864,9 +1895,9 @@ export class Query implements firestore.Query {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get documents from server. (However, these ' +
-                  'documents may exist in the local cache. Run again ' +
-                  'without setting source to "server" to ' +
-                  'retrieve the cached documents.)'
+                'documents may exist in the local cache. Run again ' +
+                'without setting source to "server" to ' +
+                'retrieve the cached documents.)'
               )
             );
           } else {
@@ -1889,7 +1920,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           'Invalid query. When querying with FieldPath.documentId(), you ' +
-            'must provide a valid document ID, but it was an empty string.'
+          'must provide a valid document ID, but it was an empty string.'
         );
       }
       if (
@@ -1899,8 +1930,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection by ` +
-            `FieldPath.documentId(), you must provide a plain document ID, but ` +
-            `'${documentIdValue}' contains a '/' character.`
+          `FieldPath.documentId(), you must provide a plain document ID, but ` +
+          `'${documentIdValue}' contains a '/' character.`
         );
       }
       const path = this._query.path.child(
@@ -1910,8 +1941,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection group by ` +
-            `FieldPath.documentId(), the value provided must result in a valid document path, ` +
-            `but '${path}' is not because it has an odd number of segments (${path.length}).`
+          `FieldPath.documentId(), the value provided must result in a valid document path, ` +
+          `but '${path}' is not because it has an odd number of segments (${path.length}).`
         );
       }
       return new RefValue(this.firestore._databaseId, new DocumentKey(path));
@@ -1922,8 +1953,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. When querying with FieldPath.documentId(), you must provide a valid ` +
-          `string or a DocumentReference, but it was: ` +
-          `${valueDescription(documentIdValue)}.`
+        `string or a DocumentReference, but it was: ` +
+        `${valueDescription(documentIdValue)}.`
       );
     }
   }
@@ -1940,28 +1971,28 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid Query. A non-empty array is required for ' +
-          `'${operator.toString()}' filters.`
+        `'${operator.toString()}' filters.`
       );
     }
     if (value.length > 10) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters support a ` +
-          'maximum of 10 elements in the value array.'
+        'maximum of 10 elements in the value array.'
       );
     }
     if (value.indexOf(null) >= 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'null' ` +
-          'in the value array.'
+        'in the value array.'
       );
     }
     if (value.filter(element => Number.isNaN(element)).length > 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'NaN' ` +
-          'in the value array.'
+        'in the value array.'
       );
     }
   }
@@ -1979,9 +2010,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. All where filters with an inequality' +
-              ' (<, <=, >, or >=) must be on the same field. But you have' +
-              ` inequality filters on '${existingField.toString()}'` +
-              ` and '${filter.field.toString()}'`
+            ' (<, <=, >, or >=) must be on the same field. But you have' +
+            ` inequality filters on '${existingField.toString()}'` +
+            ` and '${filter.field.toString()}'`
           );
         }
 
@@ -2008,13 +2039,13 @@ export class Query implements firestore.Query {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               'Invalid query. You cannot use more than one ' +
-                `'${filter.op.toString()}' filter.`
+              `'${filter.op.toString()}' filter.`
             );
           } else {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               `Invalid query. You cannot use '${filter.op.toString()}' filters ` +
-                `with '${conflictingOp.toString()}' filters.`
+              `with '${conflictingOp.toString()}' filters.`
             );
           }
         }
@@ -2040,10 +2071,10 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. You have a where filter with an inequality ` +
-          `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
-          `and so you must also use '${inequality.toString()}' ` +
-          `as your first Query.orderBy(), but your first Query.orderBy() ` +
-          `is on field '${orderBy.toString()}' instead.`
+        `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
+        `and so you must also use '${inequality.toString()}' ` +
+        `as your first Query.orderBy(), but your first Query.orderBy() ` +
+        `is on field '${orderBy.toString()}' instead.`
       );
     }
   }
@@ -2118,7 +2149,7 @@ export class QuerySnapshot implements firestore.QuerySnapshot {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'To include metadata changes with your document changes, you must ' +
-          'also pass { includeMetadataChanges:true } to onSnapshot().'
+        'also pass { includeMetadataChanges:true } to onSnapshot().'
       );
     }
 
@@ -2171,8 +2202,8 @@ function throwDocChangesMethodError(): never {
   throw new FirestoreError(
     Code.INVALID_ARGUMENT,
     'QuerySnapshot.docChanges has been changed from a property into a ' +
-      'method, so usages like "querySnapshot.docChanges" should become ' +
-      '"querySnapshot.docChanges()"'
+    'method, so usages like "querySnapshot.docChanges" should become ' +
+    '"querySnapshot.docChanges()"'
   );
 }
 
@@ -2194,7 +2225,7 @@ docChangesPropertiesToOverride.forEach(property => {
     Object.defineProperty(QuerySnapshot.prototype.docChanges, property, {
       get: () => throwDocChangesMethodError()
     });
-  } catch (err) {} // Ignore this failure intentionally
+  } catch (err) { } // Ignore this failure intentionally
 });
 
 export class CollectionReference extends Query
@@ -2205,8 +2236,8 @@ export class CollectionReference extends Query
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid collection reference. Collection ' +
-          'references must have an odd number of segments, but ' +
-          `${path.canonicalString()} has ${path.length}`
+        'references must have an odd number of segments, but ' +
+        `${path.canonicalString()} has ${path.length}`
       );
     }
   }
@@ -2287,7 +2318,7 @@ function validateSetOptions(
     throw new FirestoreError(
       Code.INVALID_ARGUMENT,
       `Invalid options passed to function ${methodName}(): You cannot specify both "merge" ` +
-        `and "mergeFields".`
+      `and "mergeFields".`
     );
   }
 
diff --git a/packages/firestore/src/core/firestore_client.ts b/packages/firestore/src/core/firestore_client.ts
index 89a818535ce..500593a7bbb 100644
--- a/packages/firestore/src/core/firestore_client.ts
+++ b/packages/firestore/src/core/firestore_client.ts
@@ -74,14 +74,14 @@ export class IndexedDbPersistenceSettings {
   constructor(
     readonly cacheSizeBytes: number,
     readonly synchronizeTabs: boolean
-  ) {}
+  ) { }
 
   lruParams(): LruParams {
     return LruParams.withCacheSize(this.cacheSizeBytes);
   }
 }
 
-export class MemoryPersistenceSettings {}
+export class MemoryPersistenceSettings { }
 
 export type InternalPersistenceSettings =
   | IndexedDbPersistenceSettings
@@ -107,7 +107,6 @@ export class FirestoreClient {
   private lruScheduler?: LruScheduler;
 
   private readonly clientId = AutoId.newId();
-  private _clientShutdown = false;
 
   // PORTING NOTE: SharedClientState is only used for multi-tab web.
   private sharedClientState: SharedClientState;
@@ -125,7 +124,7 @@ export class FirestoreClient {
      * an async I/O to complete).
      */
     private asyncQueue: AsyncQueue
-  ) {}
+  ) { }
 
   /**
    * Starts up the FirestoreClient, returning only whether or not enabling
@@ -254,8 +253,8 @@ export class FirestoreClient {
           }
           console.warn(
             'Error enabling offline persistence. Falling back to' +
-              ' persistence disabled: ' +
-              error
+            ' persistence disabled: ' +
+            error
           );
           return this.startMemoryPersistence();
         });
@@ -310,7 +309,7 @@ export class FirestoreClient {
    * this class cannot be called after the client is shutdown.
    */
   private verifyNotShutdown(): void {
-    if (this._clientShutdown) {
+    if (this.asyncQueue.isShuttingDown) {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'The client has already been shutdown.'
@@ -507,22 +506,19 @@ export class FirestoreClient {
   }
 
   shutdown(): Promise<void> {
-    return this.asyncQueue.enqueue(async () => {
-      if (!this._clientShutdown) {
-        // PORTING NOTE: LocalStore does not need an explicit shutdown on web.
-        if (this.lruScheduler) {
-          this.lruScheduler.stop();
-        }
-        await this.remoteStore.shutdown();
-        await this.sharedClientState.shutdown();
-        await this.persistence.shutdown();
-
-        // `removeChangeListener` must be called after shutting down the
-        // RemoteStore as it will prevent the RemoteStore from retrieving
-        // auth tokens.
-        this.credentials.removeChangeListener();
-        this._clientShutdown = true;
+    return this.asyncQueue.enqueueAndInitilizeShutdown(async () => {
+      // PORTING NOTE: LocalStore does not need an explicit shutdown on web.
+      if (this.lruScheduler) {
+        this.lruScheduler.stop();
       }
+      await this.remoteStore.shutdown();
+      await this.sharedClientState.shutdown();
+      await this.persistence.shutdown();
+
+      // `removeChangeListener` must be called after shutting down the
+      // RemoteStore as it will prevent the RemoteStore from retrieving
+      // auth tokens.
+      this.credentials.removeChangeListener();
     });
   }
 
@@ -561,9 +557,9 @@ export class FirestoreClient {
           throw new FirestoreError(
             Code.UNAVAILABLE,
             'Failed to get document from cache. (However, this document may ' +
-              "exist on the server. Run again without setting 'source' in " +
-              'the GetOptions to attempt to retrieve the document from the ' +
-              'server.)'
+            "exist on the server. Run again without setting 'source' in " +
+            'the GetOptions to attempt to retrieve the document from the ' +
+            'server.)'
           );
         }
       });
@@ -603,7 +599,10 @@ export class FirestoreClient {
   }
 
   get clientShutdown(): boolean {
-    return this._clientShutdown;
+    // Technically, the asyncQueue is still running, but only accepting operations
+    // related to shutdown or supposed to be run after shutdown. It is effectively
+    // shut down to the eyes of users.
+    return this.asyncQueue.isShuttingDown;
   }
 
   transaction<T>(
@@ -612,7 +611,7 @@ export class FirestoreClient {
     this.verifyNotShutdown();
     // We have to wait for the async queue to be sure syncEngine is initialized.
     return this.asyncQueue
-      .enqueue(async () => {})
+      .enqueue(async () => { })
       .then(() => this.syncEngine.runTransaction(updateFunction));
   }
 }
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 5483100b893..6c89e2b0920 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -86,7 +86,7 @@ class DelayedOperation<T extends unknown> implements CancelablePromise<T> {
     // It's normal for the deferred promise to be canceled (due to cancellation)
     // and so we attach a dummy catch callback to avoid
     // 'UnhandledPromiseRejectionWarning' log spam.
-    this.deferred.promise.catch(err => {});
+    this.deferred.promise.catch(err => { });
   }
 
   /**
@@ -188,6 +188,10 @@ export class AsyncQueue {
   // The last promise in the queue.
   private tail: Promise<unknown> = Promise.resolve();
 
+  // Is this AsyncQueue being shutting down? Once it is set to true, it will not
+  // be changed again.
+  private _isShuttingDown: boolean = false;
+
   // Operations scheduled to be queued in the future. Operations are
   // automatically removed after they are run or canceled.
   private delayedOperations: Array<DelayedOperation<unknown>> = [];
@@ -199,6 +203,10 @@ export class AsyncQueue {
   // assertion sanity-checks.
   private operationInProgress = false;
 
+  // Is this AsyncQueue being shutting down? If true, this instance will not enqueue
+  // any new operations, Promises from enqueue requests will not resolve.
+  get isShuttingDown(): boolean { return this._isShuttingDown; }
+
   /**
    * Adds a new operation to the queue without waiting for it to complete (i.e.
    * we ignore the Promise result).
@@ -208,12 +216,59 @@ export class AsyncQueue {
     this.enqueue(op);
   }
 
+  /**
+   * Regardless if the queue has initialized shutdown, adds a new operation to the
+   * queue without waiting for it to complete (i.e. we ignore the Promise result).
+   */
+  enqueueAndForgetEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): void {
+    this.verifyNotFailed();
+    // tslint:disable-next-line:no-floating-promises
+    this.enqueueInternal(op);
+  }
+
+  /**
+   * Regardless if the queue has initialized shutdown, adds a new operation to the
+   * queue.
+   */
+  private enqueueEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+    this.verifyNotFailed();
+    // tslint:disable-next-line:no-floating-promises
+    return this.enqueueInternal(op);
+  }
+
+  /**
+   * Adds a new operation to the queue and initialize the shut down of this queue.
+   * Returns a promise that will be resolved when the promise returned by the new
+   * operation is (with its value).
+   * Once this method is called, the only possible way to request running an operation
+   * is through `enqueueAndForgetEvenAfterShutdown`.
+   */
+  enqueueAndInitilizeShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+    this.verifyNotFailed();
+    if (this._isShuttingDown) {
+      // Return a Promise resolves right away if it is already shutdown.
+      return new Promise<T>((resolve) => resolve(undefined));
+    }
+
+    const promise = this.enqueueInternal(op);
+    this._isShuttingDown = true;
+    return promise;
+  }
+
   /**
    * Adds a new operation to the queue. Returns a promise that will be resolved
    * when the promise returned by the new operation is (with its value).
    */
   enqueue<T extends unknown>(op: () => Promise<T>): Promise<T> {
     this.verifyNotFailed();
+    if (this._isShuttingDown) {
+      // Return a Promise resolves to undefined right away
+      return new Promise<T>((resolve) => resolve(undefined));
+    }
+    return this.enqueueInternal(op);
+  }
+
+  private enqueueInternal<T extends unknown>(op: () => Promise<T>): Promise<T> {
     const newTail = this.tail.then(() => {
       this.operationInProgress = true;
       return op()
@@ -286,7 +341,7 @@ export class AsyncQueue {
     if (this.failure) {
       fail(
         'AsyncQueue is already failed: ' +
-          (this.failure.stack || this.failure.message)
+        (this.failure.stack || this.failure.message)
       );
     }
   }
@@ -309,7 +364,8 @@ export class AsyncQueue {
    * operations are not run.
    */
   drain(): Promise<void> {
-    return this.enqueue(() => Promise.resolve());
+    // It should still be possible to drain the queue after it is shutting down.
+    return this.enqueueEvenAfterShutdown(() => Promise.resolve());
   }
 
   /**
@@ -338,7 +394,7 @@ export class AsyncQueue {
     return this.drain().then(() => {
       assert(
         lastTimerId === TimerId.All ||
-          this.containsDelayedOperation(lastTimerId),
+        this.containsDelayedOperation(lastTimerId),
         `Attempted to drain to missing operation ${lastTimerId}`
       );
 
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index dd1b8d276a9..fc75e2170bc 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -962,7 +962,7 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  (persistence ? it : it.skip)(
+  (persistence ? it: it.skip)(
     'maintains persistence after restarting app',
     async () => {
       await withTestDoc(persistence, async docRef => {
@@ -1068,4 +1068,29 @@ apiDescribe('Database', (persistence: boolean) => {
       await db.enableNetwork();
     });
   });
+
+  it('can start a new instance after shut down', async () => {
+    return withTestDoc(persistence, async docRef => {
+      const firestore = docRef.firestore;
+      // TODO(b/135755126): use public `shutdown` once it is availabe.
+      await firestore.INTERNAL.delete();
+
+      const newFirestore = firebase.firestore!(firestore.app);
+      await newFirestore.doc(docRef.path).set({foo: 'bar'});
+      const doc = await newFirestore.doc(docRef.path).get();
+      expect(doc.data()).to.deep.equal({ foo: 'bar' });
+    });
+  });
+
+  it('app delete leads to instance shutdown', async () => {
+    await withTestDoc(persistence, async docRef => {
+      await docRef.set({ foo: 'bar' });
+      const app = docRef.firestore.app;
+      await app.delete();
+      
+      expect(docRef.firestore.INTERNAL.isShutdown()).to.be.true;
+    });
+  });
+  it('calling shutdown mutiple times should proceed', async () => {
+  });
 });
diff --git a/packages/firestore/test/unit/util/async_queue.test.ts b/packages/firestore/test/unit/util/async_queue.test.ts
index 281ff463447..bbf18694eea 100644
--- a/packages/firestore/test/unit/util/async_queue.test.ts
+++ b/packages/firestore/test/unit/util/async_queue.test.ts
@@ -209,6 +209,28 @@ describe('AsyncQueue', () => {
     await queue.drain();
     expect(completedSteps).to.deep.equal([1, 2]);
   });
+
+  it('Schedules operaions with respect to shut down', async () => {
+    const queue = new AsyncQueue();
+    const completedSteps: number[] = [];
+    const doStep = (n: number): Promise<number> =>
+      defer(() => {
+        const result = completedSteps.push(n);
+        return result;
+      });
+
+    queue.enqueueAndForget(() => doStep(1));
+
+    // After this call, only operations requested via
+    // `enqueueAndForgetEvenAfterShutdown` gets executed.
+    // tslint:disable-next-line:no-floating-promises
+    queue.enqueueAndInitilizeShutdown(() => doStep(2));
+    queue.enqueueAndForget(() => doStep(3));
+    queue.enqueueAndForgetEvenAfterShutdown(() => doStep(4));
+
+    await queue.drain();
+    expect(completedSteps).to.deep.equal([1, 2, 4]);
+  });
 });
 
 function defer<T>(op: () => T): Promise<T> {

From 2ab4b34cf27f4fdca4d9282789f0e32501d4aa4a Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Wed, 31 Jul 2019 14:38:26 -0400
Subject: [PATCH 02/10] [AUTOMATED]: Prettier Code Styling

---
 packages/firebase/index.d.ts                  |   6 +-
 packages/firestore-types/index.d.ts           |   6 +-
 packages/firestore/src/api/database.ts        | 202 +++++++++---------
 .../firestore/src/core/firestore_client.ts    |  18 +-
 packages/firestore/src/util/async_queue.ts    |  26 ++-
 .../test/integration/api/database.test.ts     |   9 +-
 6 files changed, 137 insertions(+), 130 deletions(-)

diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 0524ac36de8..6b96c36a87f 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -6225,9 +6225,9 @@ declare namespace firebase.firestore {
     /**
      * @hidden
      */
-    INTERNAL: { 
-      delete: () => Promise<void>
-      isShutdown: () => boolean
+    INTERNAL: {
+      delete: () => Promise<void>;
+      isShutdown: () => boolean;
     };
   }
 
diff --git a/packages/firestore-types/index.d.ts b/packages/firestore-types/index.d.ts
index c783db59454..efb8d4ee542 100644
--- a/packages/firestore-types/index.d.ts
+++ b/packages/firestore-types/index.d.ts
@@ -276,9 +276,9 @@ export class FirebaseFirestore {
    */
   disableNetwork(): Promise<void>;
 
-  INTERNAL: { 
-    delete: () => Promise<void>
-    isShutdown: () => boolean
+  INTERNAL: {
+    delete: () => Promise<void>;
+    isShutdown: () => boolean;
   };
 }
 
diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index 4c60c0a9c11..5a56b8a8646 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -353,7 +353,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         '"persistence" is now specified with a separate call to ' +
-        'firestore.enablePersistence().'
+          'firestore.enablePersistence().'
       );
     }
 
@@ -362,8 +362,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and its settings can no longer ' +
-        'be changed. You can only call settings() before calling any other ' +
-        'methods on a Firestore object.'
+          'be changed. You can only call settings() before calling any other ' +
+          'methods on a Firestore object.'
       );
     }
 
@@ -390,8 +390,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and persistence can no longer ' +
-        'be enabled. You can only call enablePersistence() before calling ' +
-        'any other methods on a Firestore object.'
+          'be enabled. You can only call enablePersistence() before calling ' +
+          'any other methods on a Firestore object.'
       );
     }
 
@@ -401,9 +401,9 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       if (settings.experimentalTabSynchronization !== undefined) {
         log.error(
           "The 'experimentalTabSynchronization' setting has been renamed to " +
-          "'synchronizeTabs'. In a future release, the setting will be removed " +
-          'and it is recommended that you update your ' +
-          "firestore.enablePersistence() call to use 'synchronizeTabs'."
+            "'synchronizeTabs'. In a future release, the setting will be removed " +
+            'and it is recommended that you update your ' +
+            "firestore.enablePersistence() call to use 'synchronizeTabs'."
         );
       }
       synchronizeTabs = objUtils.defaulted(
@@ -486,8 +486,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Document reference is for database ' +
-            `${otherDb.projectId}/${otherDb.database} but should be ` +
-            `for database ${thisDb.projectId}/${thisDb.database}`
+              `${otherDb.projectId}/${otherDb.database} but should be ` +
+              `for database ${thisDb.projectId}/${thisDb.database}`
           );
         }
         return new DocumentKeyReference(this._config.databaseId, value._key);
@@ -531,7 +531,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         "Firestore was not initialized using the Firebase SDK. 'app' is " +
-        'not available'
+          'not available'
       );
     }
     return this._config.firebaseApp;
@@ -543,7 +543,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
    * After shutdown only the `clearPersistence()` method may be used. Any other method
    * will throw an `FirestoreError`.
    *
-   * To restart after shutdown, simply create a new instance of FirebaseFirestore with 
+   * To restart after shutdown, simply create a new instance of FirebaseFirestore with
    * `Firebase.firestore()`.
    *
    * Shutdown does not cancel any pending writes and any promises that are awaiting a response from
@@ -603,7 +603,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid collection ID '${collectionId}' passed to function ` +
-        `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
+          `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
       );
     }
     this.ensureClientConfigured();
@@ -679,7 +679,7 @@ export class Transaction implements firestore.Transaction {
   constructor(
     private _firestore: Firestore,
     private _transaction: InternalTransaction
-  ) { }
+  ) {}
 
   get(
     documentRef: firestore.DocumentReference
@@ -736,10 +736,10 @@ export class Transaction implements firestore.Transaction {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-          'Transaction.set',
-          value,
-          options.mergeFields
-        )
+            'Transaction.set',
+            value,
+            options.mergeFields
+          )
         : this._firestore._dataConverter.parseSetData('Transaction.set', value);
     this._transaction.set(ref._key, parsed);
     return this;
@@ -813,7 +813,7 @@ export class WriteBatch implements firestore.WriteBatch {
   private _mutations = [] as Mutation[];
   private _committed = false;
 
-  constructor(private _firestore: Firestore) { }
+  constructor(private _firestore: Firestore) {}
 
   set(
     documentRef: firestore.DocumentReference,
@@ -831,10 +831,10 @@ export class WriteBatch implements firestore.WriteBatch {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-          'WriteBatch.set',
-          value,
-          options.mergeFields
-        )
+            'WriteBatch.set',
+            value,
+            options.mergeFields
+          )
         : this._firestore._dataConverter.parseSetData('WriteBatch.set', value);
     this._mutations = this._mutations.concat(
       parsed.toMutations(ref._key, Precondition.NONE)
@@ -925,7 +925,7 @@ export class WriteBatch implements firestore.WriteBatch {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'A write batch can no longer be used after commit() ' +
-        'has been called.'
+          'has been called.'
       );
     }
   }
@@ -946,8 +946,8 @@ export class DocumentReference implements firestore.DocumentReference {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid document reference. Document ' +
-        'references must have an even number of segments, but ' +
-        `${path.canonicalString()} has ${path.length}`
+          'references must have an even number of segments, but ' +
+          `${path.canonicalString()} has ${path.length}`
       );
     }
     return new DocumentReference(new DocumentKey(path), firestore);
@@ -1000,14 +1000,14 @@ export class DocumentReference implements firestore.DocumentReference {
     const parsed =
       options.merge || options.mergeFields
         ? this.firestore._dataConverter.parseMergeData(
-          'DocumentReference.set',
-          value,
-          options.mergeFields
-        )
+            'DocumentReference.set',
+            value,
+            options.mergeFields
+          )
         : this.firestore._dataConverter.parseSetData(
-          'DocumentReference.set',
-          value
-        );
+            'DocumentReference.set',
+            value
+          );
     return this._firestoreClient.write(
       parsed.toMutations(this._key, Precondition.NONE)
     );
@@ -1251,9 +1251,9 @@ export class DocumentReference implements firestore.DocumentReference {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get document from server. (However, this ' +
-                'document does exist in the local cache. Run again ' +
-                'without setting source to "server" to ' +
-                'retrieve the cached document.)'
+                  'document does exist in the local cache. Run again ' +
+                  'without setting source to "server" to ' +
+                  'retrieve the cached document.)'
               )
             );
           } else {
@@ -1270,7 +1270,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
   constructor(
     readonly hasPendingWrites: boolean,
     readonly fromCache: boolean
-  ) { }
+  ) {}
 
   isEqual(other: firestore.SnapshotMetadata): boolean {
     return (
@@ -1284,7 +1284,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
  * Options interface that can be provided to configure the deserialization of
  * DocumentSnapshots.
  */
-export interface SnapshotOptions extends firestore.SnapshotOptions { }
+export interface SnapshotOptions extends firestore.SnapshotOptions {}
 
 export class DocumentSnapshot implements firestore.DocumentSnapshot {
   constructor(
@@ -1293,7 +1293,7 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     public _document: Document | null,
     private _fromCache: boolean,
     private _hasPendingWrites: boolean
-  ) { }
+  ) {}
 
   data(
     options?: firestore.SnapshotOptions
@@ -1303,12 +1303,12 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     return !this._document
       ? undefined
       : this.convertObject(
-        this._document.data,
-        FieldValueOptions.fromSnapshotOptions(
-          options,
-          this._firestore._areTimestampsInSnapshotsEnabled()
-        )
-      );
+          this._document.data,
+          FieldValueOptions.fromSnapshotOptions(
+            options,
+            this._firestore._areTimestampsInSnapshotsEnabled()
+          )
+        );
   }
 
   get(
@@ -1387,11 +1387,11 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
         // TODO(b/64130202): Somehow support foreign references.
         log.error(
           `Document ${this._key.path} contains a document ` +
-          `reference within a different database (` +
-          `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
-          `supported. It will be treated as a reference in the current ` +
-          `database (${database.projectId}/${database.database}) ` +
-          `instead.`
+            `reference within a different database (` +
+            `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
+            `supported. It will be treated as a reference in the current ` +
+            `database (${database.projectId}/${database.database}) ` +
+            `instead.`
         );
       }
       return new DocumentReference(key, this._firestore);
@@ -1423,7 +1423,7 @@ export class QueryDocumentSnapshot extends DocumentSnapshot
 }
 
 export class Query implements firestore.Query {
-  constructor(public _query: InternalQuery, readonly firestore: Firestore) { }
+  constructor(public _query: InternalQuery, readonly firestore: Firestore) {}
 
   where(
     field: string | ExternalFieldPath,
@@ -1454,7 +1454,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid Query. You can't perform '${operator.toString()}' ` +
-          'queries on FieldPath.documentId().'
+            'queries on FieldPath.documentId().'
         );
       } else if (operator === Operator.IN) {
         this.validateDisjunctiveFilterElements(value, operator);
@@ -1503,21 +1503,21 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Function Query.orderBy() has unknown direction '${directionStr}', ` +
-        `expected 'asc' or 'desc'.`
+          `expected 'asc' or 'desc'.`
       );
     }
     if (this._query.startAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.startAt() or ' +
-        'Query.startAfter() before calling Query.orderBy().'
+          'Query.startAfter() before calling Query.orderBy().'
       );
     }
     if (this._query.endAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.endAt() or ' +
-        'Query.endBefore() before calling Query.orderBy().'
+          'Query.endBefore() before calling Query.orderBy().'
       );
     }
     const fieldPath = fieldPathFromArgument('Query.orderBy', field);
@@ -1533,7 +1533,7 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. Query limit (${n}) is invalid. Limit must be ` +
-        'positive.'
+          'positive.'
       );
     }
     return new Query(this._query.withLimit(n), this.firestore);
@@ -1624,7 +1624,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.NOT_FOUND,
           `Can't use a DocumentSnapshot that doesn't exist for ` +
-          `${methodName}().`
+            `${methodName}().`
         );
       }
       return this.boundFromDocument(methodName, snap._document!, before);
@@ -1668,10 +1668,10 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. You are trying to start or end a query using a ' +
-            'document for which the field "' +
-            orderBy.field +
-            '" is an uncommitted server timestamp. (Since the value of ' +
-            'this field is unknown, you cannot start/end a query with it.)'
+              'document for which the field "' +
+              orderBy.field +
+              '" is an uncommitted server timestamp. (Since the value of ' +
+              'this field is unknown, you cannot start/end a query with it.)'
           );
         } else if (value !== null) {
           components.push(value);
@@ -1680,8 +1680,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. You are trying to start or end a query using a ` +
-            `document for which the field '${field}' (used as the ` +
-            `orderBy) does not exist.`
+              `document for which the field '${field}' (used as the ` +
+              `orderBy) does not exist.`
           );
         }
       }
@@ -1703,8 +1703,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Too many arguments provided to ${methodName}(). ` +
-        `The number of arguments must be less than or equal to the ` +
-        `number of Query.orderBy() clauses`
+          `The number of arguments must be less than or equal to the ` +
+          `number of Query.orderBy() clauses`
       );
     }
 
@@ -1717,7 +1717,7 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. Expected a string for document ID in ` +
-            `${methodName}(), but got a ${typeof rawValue}`
+              `${methodName}(), but got a ${typeof rawValue}`
           );
         }
         if (
@@ -1727,8 +1727,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection and ordering by FieldPath.documentId(), ` +
-            `the value passed to ${methodName}() must be a plain document ID, but ` +
-            `'${rawValue}' contains a slash.`
+              `the value passed to ${methodName}() must be a plain document ID, but ` +
+              `'${rawValue}' contains a slash.`
           );
         }
         const path = this._query.path.child(ResourcePath.fromString(rawValue));
@@ -1736,9 +1736,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection group and ordering by ` +
-            `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
-            `valid document path, but '${path}' is not because it contains an odd number ` +
-            `of segments.`
+              `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
+              `valid document path, but '${path}' is not because it contains an odd number ` +
+              `of segments.`
           );
         }
         const key = new DocumentKey(path);
@@ -1895,9 +1895,9 @@ export class Query implements firestore.Query {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get documents from server. (However, these ' +
-                'documents may exist in the local cache. Run again ' +
-                'without setting source to "server" to ' +
-                'retrieve the cached documents.)'
+                  'documents may exist in the local cache. Run again ' +
+                  'without setting source to "server" to ' +
+                  'retrieve the cached documents.)'
               )
             );
           } else {
@@ -1920,7 +1920,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           'Invalid query. When querying with FieldPath.documentId(), you ' +
-          'must provide a valid document ID, but it was an empty string.'
+            'must provide a valid document ID, but it was an empty string.'
         );
       }
       if (
@@ -1930,8 +1930,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection by ` +
-          `FieldPath.documentId(), you must provide a plain document ID, but ` +
-          `'${documentIdValue}' contains a '/' character.`
+            `FieldPath.documentId(), you must provide a plain document ID, but ` +
+            `'${documentIdValue}' contains a '/' character.`
         );
       }
       const path = this._query.path.child(
@@ -1941,8 +1941,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection group by ` +
-          `FieldPath.documentId(), the value provided must result in a valid document path, ` +
-          `but '${path}' is not because it has an odd number of segments (${path.length}).`
+            `FieldPath.documentId(), the value provided must result in a valid document path, ` +
+            `but '${path}' is not because it has an odd number of segments (${path.length}).`
         );
       }
       return new RefValue(this.firestore._databaseId, new DocumentKey(path));
@@ -1953,8 +1953,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. When querying with FieldPath.documentId(), you must provide a valid ` +
-        `string or a DocumentReference, but it was: ` +
-        `${valueDescription(documentIdValue)}.`
+          `string or a DocumentReference, but it was: ` +
+          `${valueDescription(documentIdValue)}.`
       );
     }
   }
@@ -1971,28 +1971,28 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid Query. A non-empty array is required for ' +
-        `'${operator.toString()}' filters.`
+          `'${operator.toString()}' filters.`
       );
     }
     if (value.length > 10) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters support a ` +
-        'maximum of 10 elements in the value array.'
+          'maximum of 10 elements in the value array.'
       );
     }
     if (value.indexOf(null) >= 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'null' ` +
-        'in the value array.'
+          'in the value array.'
       );
     }
     if (value.filter(element => Number.isNaN(element)).length > 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'NaN' ` +
-        'in the value array.'
+          'in the value array.'
       );
     }
   }
@@ -2010,9 +2010,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. All where filters with an inequality' +
-            ' (<, <=, >, or >=) must be on the same field. But you have' +
-            ` inequality filters on '${existingField.toString()}'` +
-            ` and '${filter.field.toString()}'`
+              ' (<, <=, >, or >=) must be on the same field. But you have' +
+              ` inequality filters on '${existingField.toString()}'` +
+              ` and '${filter.field.toString()}'`
           );
         }
 
@@ -2039,13 +2039,13 @@ export class Query implements firestore.Query {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               'Invalid query. You cannot use more than one ' +
-              `'${filter.op.toString()}' filter.`
+                `'${filter.op.toString()}' filter.`
             );
           } else {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               `Invalid query. You cannot use '${filter.op.toString()}' filters ` +
-              `with '${conflictingOp.toString()}' filters.`
+                `with '${conflictingOp.toString()}' filters.`
             );
           }
         }
@@ -2071,10 +2071,10 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. You have a where filter with an inequality ` +
-        `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
-        `and so you must also use '${inequality.toString()}' ` +
-        `as your first Query.orderBy(), but your first Query.orderBy() ` +
-        `is on field '${orderBy.toString()}' instead.`
+          `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
+          `and so you must also use '${inequality.toString()}' ` +
+          `as your first Query.orderBy(), but your first Query.orderBy() ` +
+          `is on field '${orderBy.toString()}' instead.`
       );
     }
   }
@@ -2149,7 +2149,7 @@ export class QuerySnapshot implements firestore.QuerySnapshot {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'To include metadata changes with your document changes, you must ' +
-        'also pass { includeMetadataChanges:true } to onSnapshot().'
+          'also pass { includeMetadataChanges:true } to onSnapshot().'
       );
     }
 
@@ -2202,8 +2202,8 @@ function throwDocChangesMethodError(): never {
   throw new FirestoreError(
     Code.INVALID_ARGUMENT,
     'QuerySnapshot.docChanges has been changed from a property into a ' +
-    'method, so usages like "querySnapshot.docChanges" should become ' +
-    '"querySnapshot.docChanges()"'
+      'method, so usages like "querySnapshot.docChanges" should become ' +
+      '"querySnapshot.docChanges()"'
   );
 }
 
@@ -2225,7 +2225,7 @@ docChangesPropertiesToOverride.forEach(property => {
     Object.defineProperty(QuerySnapshot.prototype.docChanges, property, {
       get: () => throwDocChangesMethodError()
     });
-  } catch (err) { } // Ignore this failure intentionally
+  } catch (err) {} // Ignore this failure intentionally
 });
 
 export class CollectionReference extends Query
@@ -2236,8 +2236,8 @@ export class CollectionReference extends Query
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid collection reference. Collection ' +
-        'references must have an odd number of segments, but ' +
-        `${path.canonicalString()} has ${path.length}`
+          'references must have an odd number of segments, but ' +
+          `${path.canonicalString()} has ${path.length}`
       );
     }
   }
@@ -2318,7 +2318,7 @@ function validateSetOptions(
     throw new FirestoreError(
       Code.INVALID_ARGUMENT,
       `Invalid options passed to function ${methodName}(): You cannot specify both "merge" ` +
-      `and "mergeFields".`
+        `and "mergeFields".`
     );
   }
 
diff --git a/packages/firestore/src/core/firestore_client.ts b/packages/firestore/src/core/firestore_client.ts
index 500593a7bbb..f3dbdcd85b6 100644
--- a/packages/firestore/src/core/firestore_client.ts
+++ b/packages/firestore/src/core/firestore_client.ts
@@ -74,14 +74,14 @@ export class IndexedDbPersistenceSettings {
   constructor(
     readonly cacheSizeBytes: number,
     readonly synchronizeTabs: boolean
-  ) { }
+  ) {}
 
   lruParams(): LruParams {
     return LruParams.withCacheSize(this.cacheSizeBytes);
   }
 }
 
-export class MemoryPersistenceSettings { }
+export class MemoryPersistenceSettings {}
 
 export type InternalPersistenceSettings =
   | IndexedDbPersistenceSettings
@@ -124,7 +124,7 @@ export class FirestoreClient {
      * an async I/O to complete).
      */
     private asyncQueue: AsyncQueue
-  ) { }
+  ) {}
 
   /**
    * Starts up the FirestoreClient, returning only whether or not enabling
@@ -253,8 +253,8 @@ export class FirestoreClient {
           }
           console.warn(
             'Error enabling offline persistence. Falling back to' +
-            ' persistence disabled: ' +
-            error
+              ' persistence disabled: ' +
+              error
           );
           return this.startMemoryPersistence();
         });
@@ -557,9 +557,9 @@ export class FirestoreClient {
           throw new FirestoreError(
             Code.UNAVAILABLE,
             'Failed to get document from cache. (However, this document may ' +
-            "exist on the server. Run again without setting 'source' in " +
-            'the GetOptions to attempt to retrieve the document from the ' +
-            'server.)'
+              "exist on the server. Run again without setting 'source' in " +
+              'the GetOptions to attempt to retrieve the document from the ' +
+              'server.)'
           );
         }
       });
@@ -611,7 +611,7 @@ export class FirestoreClient {
     this.verifyNotShutdown();
     // We have to wait for the async queue to be sure syncEngine is initialized.
     return this.asyncQueue
-      .enqueue(async () => { })
+      .enqueue(async () => {})
       .then(() => this.syncEngine.runTransaction(updateFunction));
   }
 }
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 6c89e2b0920..f99af671a6e 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -86,7 +86,7 @@ class DelayedOperation<T extends unknown> implements CancelablePromise<T> {
     // It's normal for the deferred promise to be canceled (due to cancellation)
     // and so we attach a dummy catch callback to avoid
     // 'UnhandledPromiseRejectionWarning' log spam.
-    this.deferred.promise.catch(err => { });
+    this.deferred.promise.catch(err => {});
   }
 
   /**
@@ -205,7 +205,9 @@ export class AsyncQueue {
 
   // Is this AsyncQueue being shutting down? If true, this instance will not enqueue
   // any new operations, Promises from enqueue requests will not resolve.
-  get isShuttingDown(): boolean { return this._isShuttingDown; }
+  get isShuttingDown(): boolean {
+    return this._isShuttingDown;
+  }
 
   /**
    * Adds a new operation to the queue without waiting for it to complete (i.e.
@@ -220,7 +222,9 @@ export class AsyncQueue {
    * Regardless if the queue has initialized shutdown, adds a new operation to the
    * queue without waiting for it to complete (i.e. we ignore the Promise result).
    */
-  enqueueAndForgetEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): void {
+  enqueueAndForgetEvenAfterShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): void {
     this.verifyNotFailed();
     // tslint:disable-next-line:no-floating-promises
     this.enqueueInternal(op);
@@ -230,7 +234,9 @@ export class AsyncQueue {
    * Regardless if the queue has initialized shutdown, adds a new operation to the
    * queue.
    */
-  private enqueueEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+  private enqueueEvenAfterShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): Promise<T> {
     this.verifyNotFailed();
     // tslint:disable-next-line:no-floating-promises
     return this.enqueueInternal(op);
@@ -243,11 +249,13 @@ export class AsyncQueue {
    * Once this method is called, the only possible way to request running an operation
    * is through `enqueueAndForgetEvenAfterShutdown`.
    */
-  enqueueAndInitilizeShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+  enqueueAndInitilizeShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): Promise<T> {
     this.verifyNotFailed();
     if (this._isShuttingDown) {
       // Return a Promise resolves right away if it is already shutdown.
-      return new Promise<T>((resolve) => resolve(undefined));
+      return new Promise<T>(resolve => resolve(undefined));
     }
 
     const promise = this.enqueueInternal(op);
@@ -263,7 +271,7 @@ export class AsyncQueue {
     this.verifyNotFailed();
     if (this._isShuttingDown) {
       // Return a Promise resolves to undefined right away
-      return new Promise<T>((resolve) => resolve(undefined));
+      return new Promise<T>(resolve => resolve(undefined));
     }
     return this.enqueueInternal(op);
   }
@@ -341,7 +349,7 @@ export class AsyncQueue {
     if (this.failure) {
       fail(
         'AsyncQueue is already failed: ' +
-        (this.failure.stack || this.failure.message)
+          (this.failure.stack || this.failure.message)
       );
     }
   }
@@ -394,7 +402,7 @@ export class AsyncQueue {
     return this.drain().then(() => {
       assert(
         lastTimerId === TimerId.All ||
-        this.containsDelayedOperation(lastTimerId),
+          this.containsDelayedOperation(lastTimerId),
         `Attempted to drain to missing operation ${lastTimerId}`
       );
 
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index fc75e2170bc..cc14c5e305a 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -962,7 +962,7 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  (persistence ? it: it.skip)(
+  (persistence ? it : it.skip)(
     'maintains persistence after restarting app',
     async () => {
       await withTestDoc(persistence, async docRef => {
@@ -1076,7 +1076,7 @@ apiDescribe('Database', (persistence: boolean) => {
       await firestore.INTERNAL.delete();
 
       const newFirestore = firebase.firestore!(firestore.app);
-      await newFirestore.doc(docRef.path).set({foo: 'bar'});
+      await newFirestore.doc(docRef.path).set({ foo: 'bar' });
       const doc = await newFirestore.doc(docRef.path).get();
       expect(doc.data()).to.deep.equal({ foo: 'bar' });
     });
@@ -1087,10 +1087,9 @@ apiDescribe('Database', (persistence: boolean) => {
       await docRef.set({ foo: 'bar' });
       const app = docRef.firestore.app;
       await app.delete();
-      
+
       expect(docRef.firestore.INTERNAL.isShutdown()).to.be.true;
     });
   });
-  it('calling shutdown mutiple times should proceed', async () => {
-  });
+  it('calling shutdown mutiple times should proceed', async () => {});
 });

From c9e14954dbeb82c98a552b19decd02dbcdb4c87e Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Wed, 31 Jul 2019 16:46:26 -0400
Subject: [PATCH 03/10] Looks to be working.

---
 packages/firebase/index.d.ts                  |   6 +-
 packages/firestore-types/index.d.ts           |   6 +-
 packages/firestore/src/api/database.ts        | 236 ++++++++++--------
 .../firestore/src/core/firestore_client.ts    |  53 ++--
 packages/firestore/src/util/async_queue.ts    |  64 ++++-
 .../test/integration/api/database.test.ts     |  47 +++-
 .../test/unit/util/async_queue.test.ts        |  22 ++
 7 files changed, 297 insertions(+), 137 deletions(-)

diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 28b43b2a311..73997980051 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -6225,7 +6225,11 @@ declare namespace firebase.firestore {
     /**
      * @hidden
      */
-    INTERNAL: { delete: () => Promise<void> };
+    INTERNAL: { 
+      delete: () => Promise<void>
+      shutdown: () => Promise<void>
+      isShutdown: () => boolean
+    };
   }
 
   /**
diff --git a/packages/firestore-types/index.d.ts b/packages/firestore-types/index.d.ts
index c96fa5925dc..9cd263ffc18 100644
--- a/packages/firestore-types/index.d.ts
+++ b/packages/firestore-types/index.d.ts
@@ -276,7 +276,11 @@ export class FirebaseFirestore {
    */
   disableNetwork(): Promise<void>;
 
-  INTERNAL: { delete: () => Promise<void> };
+  INTERNAL: { 
+    delete: () => Promise<void>
+    shutdown: () => Promise<void>
+    isShutdown: () => boolean
+  };
 }
 
 /**
diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index 161435d773c..a5eec9caa18 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -18,7 +18,7 @@
 import * as firestore from '@firebase/firestore-types';
 
 import { FirebaseApp } from '@firebase/app-types';
-import { FirebaseService } from '@firebase/app-types/private';
+import { FirebaseService, _FirebaseApp } from '@firebase/app-types/private';
 import { DatabaseId, DatabaseInfo } from '../core/database_info';
 import { ListenOptions } from '../core/event_manager';
 import {
@@ -353,7 +353,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         '"persistence" is now specified with a separate call to ' +
-          'firestore.enablePersistence().'
+        'firestore.enablePersistence().'
       );
     }
 
@@ -362,8 +362,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and its settings can no longer ' +
-          'be changed. You can only call settings() before calling any other ' +
-          'methods on a Firestore object.'
+        'be changed. You can only call settings() before calling any other ' +
+        'methods on a Firestore object.'
       );
     }
 
@@ -390,8 +390,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and persistence can no longer ' +
-          'be enabled. You can only call enablePersistence() before calling ' +
-          'any other methods on a Firestore object.'
+        'be enabled. You can only call enablePersistence() before calling ' +
+        'any other methods on a Firestore object.'
       );
     }
 
@@ -401,9 +401,9 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       if (settings.experimentalTabSynchronization !== undefined) {
         log.error(
           "The 'experimentalTabSynchronization' setting has been renamed to " +
-            "'synchronizeTabs'. In a future release, the setting will be removed " +
-            'and it is recommended that you update your ' +
-            "firestore.enablePersistence() call to use 'synchronizeTabs'."
+          "'synchronizeTabs'. In a future release, the setting will be removed " +
+          'and it is recommended that you update your ' +
+          "firestore.enablePersistence() call to use 'synchronizeTabs'."
         );
       }
       synchronizeTabs = objUtils.defaulted(
@@ -427,7 +427,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       this.makeDatabaseInfo()
     );
     const deferred = new Deferred<void>();
-    this._queue.enqueueAndForget(async () => {
+    this._queue.enqueueAndForgetEvenAfterShutdown(async () => {
       try {
         if (
           this._firestoreClient !== undefined &&
@@ -486,8 +486,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Document reference is for database ' +
-              `${otherDb.projectId}/${otherDb.database} but should be ` +
-              `for database ${thisDb.projectId}/${thisDb.database}`
+            `${otherDb.projectId}/${otherDb.database} but should be ` +
+            `for database ${thisDb.projectId}/${thisDb.database}`
           );
         }
         return new DocumentKeyReference(this._config.databaseId, value._key);
@@ -531,7 +531,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         "Firestore was not initialized using the Firebase SDK. 'app' is " +
-          'not available'
+        'not available'
       );
     }
     return this._config.firebaseApp;
@@ -543,6 +543,36 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       // throws an exception.
       this.ensureClientConfigured();
       await this._firestoreClient!.shutdown();
+    },
+
+    /**
+     * Shuts down this FirebaseFirestore instance.
+     *
+     * After shutdown only the `clearPersistence()` method may be used. Any other method
+     * will throw an `FirestoreError`.
+     *
+     * To restart after shutdown, simply create a new instance of FirebaseFirestore with 
+     * `Firebase.firestore()`.
+     *
+     * Shutdown does not cancel any pending writes and any promises that are awaiting a response
+     * from the server will not be resolved. The next time you start this instance,
+     * it will resume attempting to send these writes to the server.
+     *
+     * Note: Under normal circumstances, calling `shutdown()` is not required. This
+     * method is useful only when you want to force this instance to release all of its resources or
+     * in combination with `clearPersistence()` to ensure that all local state is destroyed
+     * between test runs.
+     *
+     * @return A promise that is resolved when the instance has been successfully shut down.
+     */
+    // TODO(b/135755126): make this public.
+    shutdown: (): Promise<void> => {
+      (this._config.firebaseApp as _FirebaseApp)._removeServiceInstance('firestore');
+      return this.INTERNAL.delete();
+    },
+
+    isShutdown: (): boolean => {
+      return this._firestoreClient!.clientShutdown;
     }
   };
 
@@ -572,7 +602,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid collection ID '${collectionId}' passed to function ` +
-          `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
+        `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
       );
     }
     this.ensureClientConfigured();
@@ -648,7 +678,7 @@ export class Transaction implements firestore.Transaction {
   constructor(
     private _firestore: Firestore,
     private _transaction: InternalTransaction
-  ) {}
+  ) { }
 
   get(
     documentRef: firestore.DocumentReference
@@ -705,10 +735,10 @@ export class Transaction implements firestore.Transaction {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-            'Transaction.set',
-            value,
-            options.mergeFields
-          )
+          'Transaction.set',
+          value,
+          options.mergeFields
+        )
         : this._firestore._dataConverter.parseSetData('Transaction.set', value);
     this._transaction.set(ref._key, parsed);
     return this;
@@ -782,7 +812,7 @@ export class WriteBatch implements firestore.WriteBatch {
   private _mutations = [] as Mutation[];
   private _committed = false;
 
-  constructor(private _firestore: Firestore) {}
+  constructor(private _firestore: Firestore) { }
 
   set(
     documentRef: firestore.DocumentReference,
@@ -800,10 +830,10 @@ export class WriteBatch implements firestore.WriteBatch {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-            'WriteBatch.set',
-            value,
-            options.mergeFields
-          )
+          'WriteBatch.set',
+          value,
+          options.mergeFields
+        )
         : this._firestore._dataConverter.parseSetData('WriteBatch.set', value);
     this._mutations = this._mutations.concat(
       parsed.toMutations(ref._key, Precondition.NONE)
@@ -894,7 +924,7 @@ export class WriteBatch implements firestore.WriteBatch {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'A write batch can no longer be used after commit() ' +
-          'has been called.'
+        'has been called.'
       );
     }
   }
@@ -915,8 +945,8 @@ export class DocumentReference implements firestore.DocumentReference {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid document reference. Document ' +
-          'references must have an even number of segments, but ' +
-          `${path.canonicalString()} has ${path.length}`
+        'references must have an even number of segments, but ' +
+        `${path.canonicalString()} has ${path.length}`
       );
     }
     return new DocumentReference(new DocumentKey(path), firestore);
@@ -969,14 +999,14 @@ export class DocumentReference implements firestore.DocumentReference {
     const parsed =
       options.merge || options.mergeFields
         ? this.firestore._dataConverter.parseMergeData(
-            'DocumentReference.set',
-            value,
-            options.mergeFields
-          )
+          'DocumentReference.set',
+          value,
+          options.mergeFields
+        )
         : this.firestore._dataConverter.parseSetData(
-            'DocumentReference.set',
-            value
-          );
+          'DocumentReference.set',
+          value
+        );
     return this._firestoreClient.write(
       parsed.toMutations(this._key, Precondition.NONE)
     );
@@ -1020,7 +1050,7 @@ export class DocumentReference implements firestore.DocumentReference {
   }
 
   delete(): Promise<void> {
-    validateExactNumberOfArgs('DocumentReference.delete', arguments, 0);
+    validateExactNumberOfArgs('FirebaseFirestore.shutdown', arguments, 0);
     return this._firestoreClient.write([
       new DeleteMutation(this._key, Precondition.NONE)
     ]);
@@ -1220,9 +1250,9 @@ export class DocumentReference implements firestore.DocumentReference {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get document from server. (However, this ' +
-                  'document does exist in the local cache. Run again ' +
-                  'without setting source to "server" to ' +
-                  'retrieve the cached document.)'
+                'document does exist in the local cache. Run again ' +
+                'without setting source to "server" to ' +
+                'retrieve the cached document.)'
               )
             );
           } else {
@@ -1239,7 +1269,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
   constructor(
     readonly hasPendingWrites: boolean,
     readonly fromCache: boolean
-  ) {}
+  ) { }
 
   isEqual(other: firestore.SnapshotMetadata): boolean {
     return (
@@ -1253,7 +1283,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
  * Options interface that can be provided to configure the deserialization of
  * DocumentSnapshots.
  */
-export interface SnapshotOptions extends firestore.SnapshotOptions {}
+export interface SnapshotOptions extends firestore.SnapshotOptions { }
 
 export class DocumentSnapshot implements firestore.DocumentSnapshot {
   constructor(
@@ -1262,7 +1292,7 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     public _document: Document | null,
     private _fromCache: boolean,
     private _hasPendingWrites: boolean
-  ) {}
+  ) { }
 
   data(
     options?: firestore.SnapshotOptions
@@ -1272,12 +1302,12 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     return !this._document
       ? undefined
       : this.convertObject(
-          this._document.data,
-          FieldValueOptions.fromSnapshotOptions(
-            options,
-            this._firestore._areTimestampsInSnapshotsEnabled()
-          )
-        );
+        this._document.data,
+        FieldValueOptions.fromSnapshotOptions(
+          options,
+          this._firestore._areTimestampsInSnapshotsEnabled()
+        )
+      );
   }
 
   get(
@@ -1356,11 +1386,11 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
         // TODO(b/64130202): Somehow support foreign references.
         log.error(
           `Document ${this._key.path} contains a document ` +
-            `reference within a different database (` +
-            `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
-            `supported. It will be treated as a reference in the current ` +
-            `database (${database.projectId}/${database.database}) ` +
-            `instead.`
+          `reference within a different database (` +
+          `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
+          `supported. It will be treated as a reference in the current ` +
+          `database (${database.projectId}/${database.database}) ` +
+          `instead.`
         );
       }
       return new DocumentReference(key, this._firestore);
@@ -1392,7 +1422,7 @@ export class QueryDocumentSnapshot extends DocumentSnapshot
 }
 
 export class Query implements firestore.Query {
-  constructor(public _query: InternalQuery, readonly firestore: Firestore) {}
+  constructor(public _query: InternalQuery, readonly firestore: Firestore) { }
 
   where(
     field: string | ExternalFieldPath,
@@ -1423,7 +1453,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid Query. You can't perform '${operator.toString()}' ` +
-            'queries on FieldPath.documentId().'
+          'queries on FieldPath.documentId().'
         );
       } else if (operator === Operator.IN) {
         this.validateDisjunctiveFilterElements(value, operator);
@@ -1472,21 +1502,21 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Function Query.orderBy() has unknown direction '${directionStr}', ` +
-          `expected 'asc' or 'desc'.`
+        `expected 'asc' or 'desc'.`
       );
     }
     if (this._query.startAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.startAt() or ' +
-          'Query.startAfter() before calling Query.orderBy().'
+        'Query.startAfter() before calling Query.orderBy().'
       );
     }
     if (this._query.endAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.endAt() or ' +
-          'Query.endBefore() before calling Query.orderBy().'
+        'Query.endBefore() before calling Query.orderBy().'
       );
     }
     const fieldPath = fieldPathFromArgument('Query.orderBy', field);
@@ -1502,7 +1532,7 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. Query limit (${n}) is invalid. Limit must be ` +
-          'positive.'
+        'positive.'
       );
     }
     return new Query(this._query.withLimit(n), this.firestore);
@@ -1593,7 +1623,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.NOT_FOUND,
           `Can't use a DocumentSnapshot that doesn't exist for ` +
-            `${methodName}().`
+          `${methodName}().`
         );
       }
       return this.boundFromDocument(methodName, snap._document!, before);
@@ -1637,10 +1667,10 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. You are trying to start or end a query using a ' +
-              'document for which the field "' +
-              orderBy.field +
-              '" is an uncommitted server timestamp. (Since the value of ' +
-              'this field is unknown, you cannot start/end a query with it.)'
+            'document for which the field "' +
+            orderBy.field +
+            '" is an uncommitted server timestamp. (Since the value of ' +
+            'this field is unknown, you cannot start/end a query with it.)'
           );
         } else if (value !== null) {
           components.push(value);
@@ -1649,8 +1679,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. You are trying to start or end a query using a ` +
-              `document for which the field '${field}' (used as the ` +
-              `orderBy) does not exist.`
+            `document for which the field '${field}' (used as the ` +
+            `orderBy) does not exist.`
           );
         }
       }
@@ -1672,8 +1702,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Too many arguments provided to ${methodName}(). ` +
-          `The number of arguments must be less than or equal to the ` +
-          `number of Query.orderBy() clauses`
+        `The number of arguments must be less than or equal to the ` +
+        `number of Query.orderBy() clauses`
       );
     }
 
@@ -1686,7 +1716,7 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. Expected a string for document ID in ` +
-              `${methodName}(), but got a ${typeof rawValue}`
+            `${methodName}(), but got a ${typeof rawValue}`
           );
         }
         if (
@@ -1696,8 +1726,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection and ordering by FieldPath.documentId(), ` +
-              `the value passed to ${methodName}() must be a plain document ID, but ` +
-              `'${rawValue}' contains a slash.`
+            `the value passed to ${methodName}() must be a plain document ID, but ` +
+            `'${rawValue}' contains a slash.`
           );
         }
         const path = this._query.path.child(ResourcePath.fromString(rawValue));
@@ -1705,9 +1735,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection group and ordering by ` +
-              `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
-              `valid document path, but '${path}' is not because it contains an odd number ` +
-              `of segments.`
+            `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
+            `valid document path, but '${path}' is not because it contains an odd number ` +
+            `of segments.`
           );
         }
         const key = new DocumentKey(path);
@@ -1864,9 +1894,9 @@ export class Query implements firestore.Query {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get documents from server. (However, these ' +
-                  'documents may exist in the local cache. Run again ' +
-                  'without setting source to "server" to ' +
-                  'retrieve the cached documents.)'
+                'documents may exist in the local cache. Run again ' +
+                'without setting source to "server" to ' +
+                'retrieve the cached documents.)'
               )
             );
           } else {
@@ -1889,7 +1919,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           'Invalid query. When querying with FieldPath.documentId(), you ' +
-            'must provide a valid document ID, but it was an empty string.'
+          'must provide a valid document ID, but it was an empty string.'
         );
       }
       if (
@@ -1899,8 +1929,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection by ` +
-            `FieldPath.documentId(), you must provide a plain document ID, but ` +
-            `'${documentIdValue}' contains a '/' character.`
+          `FieldPath.documentId(), you must provide a plain document ID, but ` +
+          `'${documentIdValue}' contains a '/' character.`
         );
       }
       const path = this._query.path.child(
@@ -1910,8 +1940,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection group by ` +
-            `FieldPath.documentId(), the value provided must result in a valid document path, ` +
-            `but '${path}' is not because it has an odd number of segments (${path.length}).`
+          `FieldPath.documentId(), the value provided must result in a valid document path, ` +
+          `but '${path}' is not because it has an odd number of segments (${path.length}).`
         );
       }
       return new RefValue(this.firestore._databaseId, new DocumentKey(path));
@@ -1922,8 +1952,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. When querying with FieldPath.documentId(), you must provide a valid ` +
-          `string or a DocumentReference, but it was: ` +
-          `${valueDescription(documentIdValue)}.`
+        `string or a DocumentReference, but it was: ` +
+        `${valueDescription(documentIdValue)}.`
       );
     }
   }
@@ -1940,28 +1970,28 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid Query. A non-empty array is required for ' +
-          `'${operator.toString()}' filters.`
+        `'${operator.toString()}' filters.`
       );
     }
     if (value.length > 10) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters support a ` +
-          'maximum of 10 elements in the value array.'
+        'maximum of 10 elements in the value array.'
       );
     }
     if (value.indexOf(null) >= 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'null' ` +
-          'in the value array.'
+        'in the value array.'
       );
     }
     if (value.filter(element => Number.isNaN(element)).length > 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'NaN' ` +
-          'in the value array.'
+        'in the value array.'
       );
     }
   }
@@ -1979,9 +2009,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. All where filters with an inequality' +
-              ' (<, <=, >, or >=) must be on the same field. But you have' +
-              ` inequality filters on '${existingField.toString()}'` +
-              ` and '${filter.field.toString()}'`
+            ' (<, <=, >, or >=) must be on the same field. But you have' +
+            ` inequality filters on '${existingField.toString()}'` +
+            ` and '${filter.field.toString()}'`
           );
         }
 
@@ -2008,13 +2038,13 @@ export class Query implements firestore.Query {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               'Invalid query. You cannot use more than one ' +
-                `'${filter.op.toString()}' filter.`
+              `'${filter.op.toString()}' filter.`
             );
           } else {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               `Invalid query. You cannot use '${filter.op.toString()}' filters ` +
-                `with '${conflictingOp.toString()}' filters.`
+              `with '${conflictingOp.toString()}' filters.`
             );
           }
         }
@@ -2040,10 +2070,10 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. You have a where filter with an inequality ` +
-          `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
-          `and so you must also use '${inequality.toString()}' ` +
-          `as your first Query.orderBy(), but your first Query.orderBy() ` +
-          `is on field '${orderBy.toString()}' instead.`
+        `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
+        `and so you must also use '${inequality.toString()}' ` +
+        `as your first Query.orderBy(), but your first Query.orderBy() ` +
+        `is on field '${orderBy.toString()}' instead.`
       );
     }
   }
@@ -2118,7 +2148,7 @@ export class QuerySnapshot implements firestore.QuerySnapshot {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'To include metadata changes with your document changes, you must ' +
-          'also pass { includeMetadataChanges:true } to onSnapshot().'
+        'also pass { includeMetadataChanges:true } to onSnapshot().'
       );
     }
 
@@ -2171,8 +2201,8 @@ function throwDocChangesMethodError(): never {
   throw new FirestoreError(
     Code.INVALID_ARGUMENT,
     'QuerySnapshot.docChanges has been changed from a property into a ' +
-      'method, so usages like "querySnapshot.docChanges" should become ' +
-      '"querySnapshot.docChanges()"'
+    'method, so usages like "querySnapshot.docChanges" should become ' +
+    '"querySnapshot.docChanges()"'
   );
 }
 
@@ -2194,7 +2224,7 @@ docChangesPropertiesToOverride.forEach(property => {
     Object.defineProperty(QuerySnapshot.prototype.docChanges, property, {
       get: () => throwDocChangesMethodError()
     });
-  } catch (err) {} // Ignore this failure intentionally
+  } catch (err) { } // Ignore this failure intentionally
 });
 
 export class CollectionReference extends Query
@@ -2205,8 +2235,8 @@ export class CollectionReference extends Query
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid collection reference. Collection ' +
-          'references must have an odd number of segments, but ' +
-          `${path.canonicalString()} has ${path.length}`
+        'references must have an odd number of segments, but ' +
+        `${path.canonicalString()} has ${path.length}`
       );
     }
   }
@@ -2287,7 +2317,7 @@ function validateSetOptions(
     throw new FirestoreError(
       Code.INVALID_ARGUMENT,
       `Invalid options passed to function ${methodName}(): You cannot specify both "merge" ` +
-        `and "mergeFields".`
+      `and "mergeFields".`
     );
   }
 
diff --git a/packages/firestore/src/core/firestore_client.ts b/packages/firestore/src/core/firestore_client.ts
index 89a818535ce..500593a7bbb 100644
--- a/packages/firestore/src/core/firestore_client.ts
+++ b/packages/firestore/src/core/firestore_client.ts
@@ -74,14 +74,14 @@ export class IndexedDbPersistenceSettings {
   constructor(
     readonly cacheSizeBytes: number,
     readonly synchronizeTabs: boolean
-  ) {}
+  ) { }
 
   lruParams(): LruParams {
     return LruParams.withCacheSize(this.cacheSizeBytes);
   }
 }
 
-export class MemoryPersistenceSettings {}
+export class MemoryPersistenceSettings { }
 
 export type InternalPersistenceSettings =
   | IndexedDbPersistenceSettings
@@ -107,7 +107,6 @@ export class FirestoreClient {
   private lruScheduler?: LruScheduler;
 
   private readonly clientId = AutoId.newId();
-  private _clientShutdown = false;
 
   // PORTING NOTE: SharedClientState is only used for multi-tab web.
   private sharedClientState: SharedClientState;
@@ -125,7 +124,7 @@ export class FirestoreClient {
      * an async I/O to complete).
      */
     private asyncQueue: AsyncQueue
-  ) {}
+  ) { }
 
   /**
    * Starts up the FirestoreClient, returning only whether or not enabling
@@ -254,8 +253,8 @@ export class FirestoreClient {
           }
           console.warn(
             'Error enabling offline persistence. Falling back to' +
-              ' persistence disabled: ' +
-              error
+            ' persistence disabled: ' +
+            error
           );
           return this.startMemoryPersistence();
         });
@@ -310,7 +309,7 @@ export class FirestoreClient {
    * this class cannot be called after the client is shutdown.
    */
   private verifyNotShutdown(): void {
-    if (this._clientShutdown) {
+    if (this.asyncQueue.isShuttingDown) {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'The client has already been shutdown.'
@@ -507,22 +506,19 @@ export class FirestoreClient {
   }
 
   shutdown(): Promise<void> {
-    return this.asyncQueue.enqueue(async () => {
-      if (!this._clientShutdown) {
-        // PORTING NOTE: LocalStore does not need an explicit shutdown on web.
-        if (this.lruScheduler) {
-          this.lruScheduler.stop();
-        }
-        await this.remoteStore.shutdown();
-        await this.sharedClientState.shutdown();
-        await this.persistence.shutdown();
-
-        // `removeChangeListener` must be called after shutting down the
-        // RemoteStore as it will prevent the RemoteStore from retrieving
-        // auth tokens.
-        this.credentials.removeChangeListener();
-        this._clientShutdown = true;
+    return this.asyncQueue.enqueueAndInitilizeShutdown(async () => {
+      // PORTING NOTE: LocalStore does not need an explicit shutdown on web.
+      if (this.lruScheduler) {
+        this.lruScheduler.stop();
       }
+      await this.remoteStore.shutdown();
+      await this.sharedClientState.shutdown();
+      await this.persistence.shutdown();
+
+      // `removeChangeListener` must be called after shutting down the
+      // RemoteStore as it will prevent the RemoteStore from retrieving
+      // auth tokens.
+      this.credentials.removeChangeListener();
     });
   }
 
@@ -561,9 +557,9 @@ export class FirestoreClient {
           throw new FirestoreError(
             Code.UNAVAILABLE,
             'Failed to get document from cache. (However, this document may ' +
-              "exist on the server. Run again without setting 'source' in " +
-              'the GetOptions to attempt to retrieve the document from the ' +
-              'server.)'
+            "exist on the server. Run again without setting 'source' in " +
+            'the GetOptions to attempt to retrieve the document from the ' +
+            'server.)'
           );
         }
       });
@@ -603,7 +599,10 @@ export class FirestoreClient {
   }
 
   get clientShutdown(): boolean {
-    return this._clientShutdown;
+    // Technically, the asyncQueue is still running, but only accepting operations
+    // related to shutdown or supposed to be run after shutdown. It is effectively
+    // shut down to the eyes of users.
+    return this.asyncQueue.isShuttingDown;
   }
 
   transaction<T>(
@@ -612,7 +611,7 @@ export class FirestoreClient {
     this.verifyNotShutdown();
     // We have to wait for the async queue to be sure syncEngine is initialized.
     return this.asyncQueue
-      .enqueue(async () => {})
+      .enqueue(async () => { })
       .then(() => this.syncEngine.runTransaction(updateFunction));
   }
 }
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 5483100b893..b6d45b961c0 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -86,7 +86,7 @@ class DelayedOperation<T extends unknown> implements CancelablePromise<T> {
     // It's normal for the deferred promise to be canceled (due to cancellation)
     // and so we attach a dummy catch callback to avoid
     // 'UnhandledPromiseRejectionWarning' log spam.
-    this.deferred.promise.catch(err => {});
+    this.deferred.promise.catch(err => { });
   }
 
   /**
@@ -188,6 +188,10 @@ export class AsyncQueue {
   // The last promise in the queue.
   private tail: Promise<unknown> = Promise.resolve();
 
+  // Is this AsyncQueue being shutting down? Once it is set to true, it will not
+  // be changed again.
+  private _isShuttingDown: boolean = false;
+
   // Operations scheduled to be queued in the future. Operations are
   // automatically removed after they are run or canceled.
   private delayedOperations: Array<DelayedOperation<unknown>> = [];
@@ -199,6 +203,10 @@ export class AsyncQueue {
   // assertion sanity-checks.
   private operationInProgress = false;
 
+  // Is this AsyncQueue being shutting down? If true, this instance will not enqueue
+  // any new operations, Promises from enqueue requests will not resolve.
+  get isShuttingDown(): boolean { return this._isShuttingDown; }
+
   /**
    * Adds a new operation to the queue without waiting for it to complete (i.e.
    * we ignore the Promise result).
@@ -208,12 +216,59 @@ export class AsyncQueue {
     this.enqueue(op);
   }
 
+  /**
+   * Regardless if the queue has initialized shutdown, adds a new operation to the
+   * queue without waiting for it to complete (i.e. we ignore the Promise result).
+   */
+  enqueueAndForgetEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): void {
+    this.verifyNotFailed();
+    // tslint:disable-next-line:no-floating-promises
+    this.enqueueInternal(op);
+  }
+
+  /**
+   * Regardless if the queue has initialized shutdown, adds a new operation to the
+   * queue.
+   */
+  private enqueueEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+    this.verifyNotFailed();
+    // tslint:disable-next-line:no-floating-promises
+    return this.enqueueInternal(op);
+  }
+
+  /**
+   * Adds a new operation to the queue and initialize the shut down of this queue.
+   * Returns a promise that will be resolved when the promise returned by the new
+   * operation is (with its value).
+   * Once this method is called, the only possible way to request running an operation
+   * is through `enqueueAndForgetEvenAfterShutdown`.
+   */
+  enqueueAndInitilizeShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+    this.verifyNotFailed();
+    if (this._isShuttingDown) {
+      // Return a Promise resolves right away if it is already shutdown.
+      return new Promise<T>((resolve) => resolve(undefined));
+    }
+
+    const promise = this.enqueueInternal(op);
+    this._isShuttingDown = true;
+    return promise;
+  }
+
   /**
    * Adds a new operation to the queue. Returns a promise that will be resolved
    * when the promise returned by the new operation is (with its value).
    */
   enqueue<T extends unknown>(op: () => Promise<T>): Promise<T> {
     this.verifyNotFailed();
+    if (this._isShuttingDown) {
+      // Return a Promise which never resolves.
+      return new Promise<T>((resolve) => {});
+    }
+    return this.enqueueInternal(op);
+  }
+
+  private enqueueInternal<T extends unknown>(op: () => Promise<T>): Promise<T> {
     const newTail = this.tail.then(() => {
       this.operationInProgress = true;
       return op()
@@ -286,7 +341,7 @@ export class AsyncQueue {
     if (this.failure) {
       fail(
         'AsyncQueue is already failed: ' +
-          (this.failure.stack || this.failure.message)
+        (this.failure.stack || this.failure.message)
       );
     }
   }
@@ -309,7 +364,8 @@ export class AsyncQueue {
    * operations are not run.
    */
   drain(): Promise<void> {
-    return this.enqueue(() => Promise.resolve());
+    // It should still be possible to drain the queue after it is shutting down.
+    return this.enqueueEvenAfterShutdown(() => Promise.resolve());
   }
 
   /**
@@ -338,7 +394,7 @@ export class AsyncQueue {
     return this.drain().then(() => {
       assert(
         lastTimerId === TimerId.All ||
-          this.containsDelayedOperation(lastTimerId),
+        this.containsDelayedOperation(lastTimerId),
         `Attempted to drain to missing operation ${lastTimerId}`
       );
 
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index dd1b8d276a9..b834d8a5a21 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -962,7 +962,7 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  (persistence ? it : it.skip)(
+  (persistence ? it: it.skip)(
     'maintains persistence after restarting app',
     async () => {
       await withTestDoc(persistence, async docRef => {
@@ -1068,4 +1068,49 @@ apiDescribe('Database', (persistence: boolean) => {
       await db.enableNetwork();
     });
   });
+
+  it('can start a new instance after shut down', async () => {
+    return withTestDoc(persistence, async docRef => {
+      const firestore = docRef.firestore;
+      await firestore.INTERNAL.shutdown();
+
+      const newFirestore = firebase.firestore!(firestore.app);
+      await newFirestore.doc(docRef.path).set({foo: 'bar'});
+      const doc = await newFirestore.doc(docRef.path).get();
+      expect(doc.data()).to.deep.equal({ foo: 'bar' });
+    });
+  });
+
+  it('app delete leads to instance shutdown', async () => {
+    await withTestDoc(persistence, async docRef => {
+      await docRef.set({ foo: 'bar' });
+      const app = docRef.firestore.app;
+      await app.delete();
+      
+      expect(docRef.firestore.INTERNAL.isShutdown()).to.be.true;
+    });
+  });
+
+  it('new operation after shutdown should throw', async () => {
+    await withTestDoc(persistence, async docRef => {
+      const firestore = docRef.firestore;
+      await firestore.INTERNAL.shutdown();
+
+      expect(() => {
+        firestore.doc(docRef.path).set({foo: 'bar'});
+      }).to.throw();
+    });
+  });
+
+  it('calling shutdown mutiple times should proceed', async () => {
+    await withTestDoc(persistence, async docRef => {
+      const firestore = docRef.firestore;
+      await firestore.INTERNAL.shutdown();
+      await firestore.INTERNAL.shutdown();
+
+      expect(() => {
+        firestore.doc(docRef.path).set({foo: 'bar'});
+      }).to.throw();
+    });
+  });
 });
diff --git a/packages/firestore/test/unit/util/async_queue.test.ts b/packages/firestore/test/unit/util/async_queue.test.ts
index 281ff463447..bbf18694eea 100644
--- a/packages/firestore/test/unit/util/async_queue.test.ts
+++ b/packages/firestore/test/unit/util/async_queue.test.ts
@@ -209,6 +209,28 @@ describe('AsyncQueue', () => {
     await queue.drain();
     expect(completedSteps).to.deep.equal([1, 2]);
   });
+
+  it('Schedules operaions with respect to shut down', async () => {
+    const queue = new AsyncQueue();
+    const completedSteps: number[] = [];
+    const doStep = (n: number): Promise<number> =>
+      defer(() => {
+        const result = completedSteps.push(n);
+        return result;
+      });
+
+    queue.enqueueAndForget(() => doStep(1));
+
+    // After this call, only operations requested via
+    // `enqueueAndForgetEvenAfterShutdown` gets executed.
+    // tslint:disable-next-line:no-floating-promises
+    queue.enqueueAndInitilizeShutdown(() => doStep(2));
+    queue.enqueueAndForget(() => doStep(3));
+    queue.enqueueAndForgetEvenAfterShutdown(() => doStep(4));
+
+    await queue.drain();
+    expect(completedSteps).to.deep.equal([1, 2, 4]);
+  });
 });
 
 function defer<T>(op: () => T): Promise<T> {

From efffc5eb96796fcf6e3cd5488ec5188938ca650c Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Thu, 1 Aug 2019 11:05:49 -0400
Subject: [PATCH 04/10] browser passes/node fails

---
 packages/firestore/test/integration/api/database.test.ts | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index b834d8a5a21..a8d317f90cc 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -21,7 +21,7 @@ import * as firestore from '@firebase/firestore-types';
 import { expect, use } from 'chai';
 
 import { SimpleDb } from '../../../src/local/simple_db';
-import { fail } from '../../../src/util/assert';
+import { fail, assert } from '../../../src/util/assert';
 import { Code } from '../../../src/util/error';
 import { query } from '../../util/api_helpers';
 import { Deferred } from '../../util/promise';
@@ -1069,12 +1069,13 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  it('can start a new instance after shut down', async () => {
+  it.only('can start a new instance after shut down', async () => {
     return withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
       await firestore.INTERNAL.shutdown();
 
       const newFirestore = firebase.firestore!(firestore.app);
+      expect(newFirestore).to.not.equal(firestore);
       await newFirestore.doc(docRef.path).set({foo: 'bar'});
       const doc = await newFirestore.doc(docRef.path).get();
       expect(doc.data()).to.deep.equal({ foo: 'bar' });

From a07588c79f804efb7ce5cb18de5aac624eddf567 Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Thu, 1 Aug 2019 11:08:29 -0400
Subject: [PATCH 05/10] [AUTOMATED]: Prettier Code Styling

---
 packages/firebase/index.d.ts                  |   8 +-
 packages/firestore-types/index.d.ts           |   8 +-
 packages/firestore/src/api/database.ts        | 206 +++++++++---------
 .../firestore/src/core/firestore_client.ts    |  18 +-
 packages/firestore/src/util/async_queue.ts    |  26 ++-
 .../test/integration/api/database.test.ts     |  10 +-
 6 files changed, 143 insertions(+), 133 deletions(-)

diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 73997980051..79e516c8938 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -6225,10 +6225,10 @@ declare namespace firebase.firestore {
     /**
      * @hidden
      */
-    INTERNAL: { 
-      delete: () => Promise<void>
-      shutdown: () => Promise<void>
-      isShutdown: () => boolean
+    INTERNAL: {
+      delete: () => Promise<void>;
+      shutdown: () => Promise<void>;
+      isShutdown: () => boolean;
     };
   }
 
diff --git a/packages/firestore-types/index.d.ts b/packages/firestore-types/index.d.ts
index 9cd263ffc18..eb66cd1830d 100644
--- a/packages/firestore-types/index.d.ts
+++ b/packages/firestore-types/index.d.ts
@@ -276,10 +276,10 @@ export class FirebaseFirestore {
    */
   disableNetwork(): Promise<void>;
 
-  INTERNAL: { 
-    delete: () => Promise<void>
-    shutdown: () => Promise<void>
-    isShutdown: () => boolean
+  INTERNAL: {
+    delete: () => Promise<void>;
+    shutdown: () => Promise<void>;
+    isShutdown: () => boolean;
   };
 }
 
diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index a5eec9caa18..570d34466a8 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -353,7 +353,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         '"persistence" is now specified with a separate call to ' +
-        'firestore.enablePersistence().'
+          'firestore.enablePersistence().'
       );
     }
 
@@ -362,8 +362,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and its settings can no longer ' +
-        'be changed. You can only call settings() before calling any other ' +
-        'methods on a Firestore object.'
+          'be changed. You can only call settings() before calling any other ' +
+          'methods on a Firestore object.'
       );
     }
 
@@ -390,8 +390,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'Firestore has already been started and persistence can no longer ' +
-        'be enabled. You can only call enablePersistence() before calling ' +
-        'any other methods on a Firestore object.'
+          'be enabled. You can only call enablePersistence() before calling ' +
+          'any other methods on a Firestore object.'
       );
     }
 
@@ -401,9 +401,9 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       if (settings.experimentalTabSynchronization !== undefined) {
         log.error(
           "The 'experimentalTabSynchronization' setting has been renamed to " +
-          "'synchronizeTabs'. In a future release, the setting will be removed " +
-          'and it is recommended that you update your ' +
-          "firestore.enablePersistence() call to use 'synchronizeTabs'."
+            "'synchronizeTabs'. In a future release, the setting will be removed " +
+            'and it is recommended that you update your ' +
+            "firestore.enablePersistence() call to use 'synchronizeTabs'."
         );
       }
       synchronizeTabs = objUtils.defaulted(
@@ -486,8 +486,8 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Document reference is for database ' +
-            `${otherDb.projectId}/${otherDb.database} but should be ` +
-            `for database ${thisDb.projectId}/${thisDb.database}`
+              `${otherDb.projectId}/${otherDb.database} but should be ` +
+              `for database ${thisDb.projectId}/${thisDb.database}`
           );
         }
         return new DocumentKeyReference(this._config.databaseId, value._key);
@@ -531,7 +531,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         "Firestore was not initialized using the Firebase SDK. 'app' is " +
-        'not available'
+          'not available'
       );
     }
     return this._config.firebaseApp;
@@ -551,7 +551,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
      * After shutdown only the `clearPersistence()` method may be used. Any other method
      * will throw an `FirestoreError`.
      *
-     * To restart after shutdown, simply create a new instance of FirebaseFirestore with 
+     * To restart after shutdown, simply create a new instance of FirebaseFirestore with
      * `Firebase.firestore()`.
      *
      * Shutdown does not cancel any pending writes and any promises that are awaiting a response
@@ -567,7 +567,9 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
      */
     // TODO(b/135755126): make this public.
     shutdown: (): Promise<void> => {
-      (this._config.firebaseApp as _FirebaseApp)._removeServiceInstance('firestore');
+      (this._config.firebaseApp as _FirebaseApp)._removeServiceInstance(
+        'firestore'
+      );
       return this.INTERNAL.delete();
     },
 
@@ -602,7 +604,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid collection ID '${collectionId}' passed to function ` +
-        `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
+          `Firestore.collectionGroup(). Collection IDs must not contain '/'.`
       );
     }
     this.ensureClientConfigured();
@@ -678,7 +680,7 @@ export class Transaction implements firestore.Transaction {
   constructor(
     private _firestore: Firestore,
     private _transaction: InternalTransaction
-  ) { }
+  ) {}
 
   get(
     documentRef: firestore.DocumentReference
@@ -735,10 +737,10 @@ export class Transaction implements firestore.Transaction {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-          'Transaction.set',
-          value,
-          options.mergeFields
-        )
+            'Transaction.set',
+            value,
+            options.mergeFields
+          )
         : this._firestore._dataConverter.parseSetData('Transaction.set', value);
     this._transaction.set(ref._key, parsed);
     return this;
@@ -812,7 +814,7 @@ export class WriteBatch implements firestore.WriteBatch {
   private _mutations = [] as Mutation[];
   private _committed = false;
 
-  constructor(private _firestore: Firestore) { }
+  constructor(private _firestore: Firestore) {}
 
   set(
     documentRef: firestore.DocumentReference,
@@ -830,10 +832,10 @@ export class WriteBatch implements firestore.WriteBatch {
     const parsed =
       options.merge || options.mergeFields
         ? this._firestore._dataConverter.parseMergeData(
-          'WriteBatch.set',
-          value,
-          options.mergeFields
-        )
+            'WriteBatch.set',
+            value,
+            options.mergeFields
+          )
         : this._firestore._dataConverter.parseSetData('WriteBatch.set', value);
     this._mutations = this._mutations.concat(
       parsed.toMutations(ref._key, Precondition.NONE)
@@ -924,7 +926,7 @@ export class WriteBatch implements firestore.WriteBatch {
       throw new FirestoreError(
         Code.FAILED_PRECONDITION,
         'A write batch can no longer be used after commit() ' +
-        'has been called.'
+          'has been called.'
       );
     }
   }
@@ -945,8 +947,8 @@ export class DocumentReference implements firestore.DocumentReference {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid document reference. Document ' +
-        'references must have an even number of segments, but ' +
-        `${path.canonicalString()} has ${path.length}`
+          'references must have an even number of segments, but ' +
+          `${path.canonicalString()} has ${path.length}`
       );
     }
     return new DocumentReference(new DocumentKey(path), firestore);
@@ -999,14 +1001,14 @@ export class DocumentReference implements firestore.DocumentReference {
     const parsed =
       options.merge || options.mergeFields
         ? this.firestore._dataConverter.parseMergeData(
-          'DocumentReference.set',
-          value,
-          options.mergeFields
-        )
+            'DocumentReference.set',
+            value,
+            options.mergeFields
+          )
         : this.firestore._dataConverter.parseSetData(
-          'DocumentReference.set',
-          value
-        );
+            'DocumentReference.set',
+            value
+          );
     return this._firestoreClient.write(
       parsed.toMutations(this._key, Precondition.NONE)
     );
@@ -1250,9 +1252,9 @@ export class DocumentReference implements firestore.DocumentReference {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get document from server. (However, this ' +
-                'document does exist in the local cache. Run again ' +
-                'without setting source to "server" to ' +
-                'retrieve the cached document.)'
+                  'document does exist in the local cache. Run again ' +
+                  'without setting source to "server" to ' +
+                  'retrieve the cached document.)'
               )
             );
           } else {
@@ -1269,7 +1271,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
   constructor(
     readonly hasPendingWrites: boolean,
     readonly fromCache: boolean
-  ) { }
+  ) {}
 
   isEqual(other: firestore.SnapshotMetadata): boolean {
     return (
@@ -1283,7 +1285,7 @@ class SnapshotMetadata implements firestore.SnapshotMetadata {
  * Options interface that can be provided to configure the deserialization of
  * DocumentSnapshots.
  */
-export interface SnapshotOptions extends firestore.SnapshotOptions { }
+export interface SnapshotOptions extends firestore.SnapshotOptions {}
 
 export class DocumentSnapshot implements firestore.DocumentSnapshot {
   constructor(
@@ -1292,7 +1294,7 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     public _document: Document | null,
     private _fromCache: boolean,
     private _hasPendingWrites: boolean
-  ) { }
+  ) {}
 
   data(
     options?: firestore.SnapshotOptions
@@ -1302,12 +1304,12 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
     return !this._document
       ? undefined
       : this.convertObject(
-        this._document.data,
-        FieldValueOptions.fromSnapshotOptions(
-          options,
-          this._firestore._areTimestampsInSnapshotsEnabled()
-        )
-      );
+          this._document.data,
+          FieldValueOptions.fromSnapshotOptions(
+            options,
+            this._firestore._areTimestampsInSnapshotsEnabled()
+          )
+        );
   }
 
   get(
@@ -1386,11 +1388,11 @@ export class DocumentSnapshot implements firestore.DocumentSnapshot {
         // TODO(b/64130202): Somehow support foreign references.
         log.error(
           `Document ${this._key.path} contains a document ` +
-          `reference within a different database (` +
-          `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
-          `supported. It will be treated as a reference in the current ` +
-          `database (${database.projectId}/${database.database}) ` +
-          `instead.`
+            `reference within a different database (` +
+            `${value.databaseId.projectId}/${value.databaseId.database}) which is not ` +
+            `supported. It will be treated as a reference in the current ` +
+            `database (${database.projectId}/${database.database}) ` +
+            `instead.`
         );
       }
       return new DocumentReference(key, this._firestore);
@@ -1422,7 +1424,7 @@ export class QueryDocumentSnapshot extends DocumentSnapshot
 }
 
 export class Query implements firestore.Query {
-  constructor(public _query: InternalQuery, readonly firestore: Firestore) { }
+  constructor(public _query: InternalQuery, readonly firestore: Firestore) {}
 
   where(
     field: string | ExternalFieldPath,
@@ -1453,7 +1455,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid Query. You can't perform '${operator.toString()}' ` +
-          'queries on FieldPath.documentId().'
+            'queries on FieldPath.documentId().'
         );
       } else if (operator === Operator.IN) {
         this.validateDisjunctiveFilterElements(value, operator);
@@ -1502,21 +1504,21 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Function Query.orderBy() has unknown direction '${directionStr}', ` +
-        `expected 'asc' or 'desc'.`
+          `expected 'asc' or 'desc'.`
       );
     }
     if (this._query.startAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.startAt() or ' +
-        'Query.startAfter() before calling Query.orderBy().'
+          'Query.startAfter() before calling Query.orderBy().'
       );
     }
     if (this._query.endAt !== null) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid query. You must not call Query.endAt() or ' +
-        'Query.endBefore() before calling Query.orderBy().'
+          'Query.endBefore() before calling Query.orderBy().'
       );
     }
     const fieldPath = fieldPathFromArgument('Query.orderBy', field);
@@ -1532,7 +1534,7 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. Query limit (${n}) is invalid. Limit must be ` +
-        'positive.'
+          'positive.'
       );
     }
     return new Query(this._query.withLimit(n), this.firestore);
@@ -1623,7 +1625,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.NOT_FOUND,
           `Can't use a DocumentSnapshot that doesn't exist for ` +
-          `${methodName}().`
+            `${methodName}().`
         );
       }
       return this.boundFromDocument(methodName, snap._document!, before);
@@ -1667,10 +1669,10 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. You are trying to start or end a query using a ' +
-            'document for which the field "' +
-            orderBy.field +
-            '" is an uncommitted server timestamp. (Since the value of ' +
-            'this field is unknown, you cannot start/end a query with it.)'
+              'document for which the field "' +
+              orderBy.field +
+              '" is an uncommitted server timestamp. (Since the value of ' +
+              'this field is unknown, you cannot start/end a query with it.)'
           );
         } else if (value !== null) {
           components.push(value);
@@ -1679,8 +1681,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. You are trying to start or end a query using a ` +
-            `document for which the field '${field}' (used as the ` +
-            `orderBy) does not exist.`
+              `document for which the field '${field}' (used as the ` +
+              `orderBy) does not exist.`
           );
         }
       }
@@ -1702,8 +1704,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Too many arguments provided to ${methodName}(). ` +
-        `The number of arguments must be less than or equal to the ` +
-        `number of Query.orderBy() clauses`
+          `The number of arguments must be less than or equal to the ` +
+          `number of Query.orderBy() clauses`
       );
     }
 
@@ -1716,7 +1718,7 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. Expected a string for document ID in ` +
-            `${methodName}(), but got a ${typeof rawValue}`
+              `${methodName}(), but got a ${typeof rawValue}`
           );
         }
         if (
@@ -1726,8 +1728,8 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection and ordering by FieldPath.documentId(), ` +
-            `the value passed to ${methodName}() must be a plain document ID, but ` +
-            `'${rawValue}' contains a slash.`
+              `the value passed to ${methodName}() must be a plain document ID, but ` +
+              `'${rawValue}' contains a slash.`
           );
         }
         const path = this._query.path.child(ResourcePath.fromString(rawValue));
@@ -1735,9 +1737,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             `Invalid query. When querying a collection group and ordering by ` +
-            `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
-            `valid document path, but '${path}' is not because it contains an odd number ` +
-            `of segments.`
+              `FieldPath.documentId(), the value passed to ${methodName}() must result in a ` +
+              `valid document path, but '${path}' is not because it contains an odd number ` +
+              `of segments.`
           );
         }
         const key = new DocumentKey(path);
@@ -1894,9 +1896,9 @@ export class Query implements firestore.Query {
               new FirestoreError(
                 Code.UNAVAILABLE,
                 'Failed to get documents from server. (However, these ' +
-                'documents may exist in the local cache. Run again ' +
-                'without setting source to "server" to ' +
-                'retrieve the cached documents.)'
+                  'documents may exist in the local cache. Run again ' +
+                  'without setting source to "server" to ' +
+                  'retrieve the cached documents.)'
               )
             );
           } else {
@@ -1919,7 +1921,7 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           'Invalid query. When querying with FieldPath.documentId(), you ' +
-          'must provide a valid document ID, but it was an empty string.'
+            'must provide a valid document ID, but it was an empty string.'
         );
       }
       if (
@@ -1929,8 +1931,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection by ` +
-          `FieldPath.documentId(), you must provide a plain document ID, but ` +
-          `'${documentIdValue}' contains a '/' character.`
+            `FieldPath.documentId(), you must provide a plain document ID, but ` +
+            `'${documentIdValue}' contains a '/' character.`
         );
       }
       const path = this._query.path.child(
@@ -1940,8 +1942,8 @@ export class Query implements firestore.Query {
         throw new FirestoreError(
           Code.INVALID_ARGUMENT,
           `Invalid query. When querying a collection group by ` +
-          `FieldPath.documentId(), the value provided must result in a valid document path, ` +
-          `but '${path}' is not because it has an odd number of segments (${path.length}).`
+            `FieldPath.documentId(), the value provided must result in a valid document path, ` +
+            `but '${path}' is not because it has an odd number of segments (${path.length}).`
         );
       }
       return new RefValue(this.firestore._databaseId, new DocumentKey(path));
@@ -1952,8 +1954,8 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. When querying with FieldPath.documentId(), you must provide a valid ` +
-        `string or a DocumentReference, but it was: ` +
-        `${valueDescription(documentIdValue)}.`
+          `string or a DocumentReference, but it was: ` +
+          `${valueDescription(documentIdValue)}.`
       );
     }
   }
@@ -1970,28 +1972,28 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid Query. A non-empty array is required for ' +
-        `'${operator.toString()}' filters.`
+          `'${operator.toString()}' filters.`
       );
     }
     if (value.length > 10) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters support a ` +
-        'maximum of 10 elements in the value array.'
+          'maximum of 10 elements in the value array.'
       );
     }
     if (value.indexOf(null) >= 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'null' ` +
-        'in the value array.'
+          'in the value array.'
       );
     }
     if (value.filter(element => Number.isNaN(element)).length > 0) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid Query. '${operator.toString()}' filters cannot contain 'NaN' ` +
-        'in the value array.'
+          'in the value array.'
       );
     }
   }
@@ -2009,9 +2011,9 @@ export class Query implements firestore.Query {
           throw new FirestoreError(
             Code.INVALID_ARGUMENT,
             'Invalid query. All where filters with an inequality' +
-            ' (<, <=, >, or >=) must be on the same field. But you have' +
-            ` inequality filters on '${existingField.toString()}'` +
-            ` and '${filter.field.toString()}'`
+              ' (<, <=, >, or >=) must be on the same field. But you have' +
+              ` inequality filters on '${existingField.toString()}'` +
+              ` and '${filter.field.toString()}'`
           );
         }
 
@@ -2038,13 +2040,13 @@ export class Query implements firestore.Query {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               'Invalid query. You cannot use more than one ' +
-              `'${filter.op.toString()}' filter.`
+                `'${filter.op.toString()}' filter.`
             );
           } else {
             throw new FirestoreError(
               Code.INVALID_ARGUMENT,
               `Invalid query. You cannot use '${filter.op.toString()}' filters ` +
-              `with '${conflictingOp.toString()}' filters.`
+                `with '${conflictingOp.toString()}' filters.`
             );
           }
         }
@@ -2070,10 +2072,10 @@ export class Query implements firestore.Query {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         `Invalid query. You have a where filter with an inequality ` +
-        `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
-        `and so you must also use '${inequality.toString()}' ` +
-        `as your first Query.orderBy(), but your first Query.orderBy() ` +
-        `is on field '${orderBy.toString()}' instead.`
+          `(<, <=, >, or >=) on field '${inequality.toString()}' ` +
+          `and so you must also use '${inequality.toString()}' ` +
+          `as your first Query.orderBy(), but your first Query.orderBy() ` +
+          `is on field '${orderBy.toString()}' instead.`
       );
     }
   }
@@ -2148,7 +2150,7 @@ export class QuerySnapshot implements firestore.QuerySnapshot {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'To include metadata changes with your document changes, you must ' +
-        'also pass { includeMetadataChanges:true } to onSnapshot().'
+          'also pass { includeMetadataChanges:true } to onSnapshot().'
       );
     }
 
@@ -2201,8 +2203,8 @@ function throwDocChangesMethodError(): never {
   throw new FirestoreError(
     Code.INVALID_ARGUMENT,
     'QuerySnapshot.docChanges has been changed from a property into a ' +
-    'method, so usages like "querySnapshot.docChanges" should become ' +
-    '"querySnapshot.docChanges()"'
+      'method, so usages like "querySnapshot.docChanges" should become ' +
+      '"querySnapshot.docChanges()"'
   );
 }
 
@@ -2224,7 +2226,7 @@ docChangesPropertiesToOverride.forEach(property => {
     Object.defineProperty(QuerySnapshot.prototype.docChanges, property, {
       get: () => throwDocChangesMethodError()
     });
-  } catch (err) { } // Ignore this failure intentionally
+  } catch (err) {} // Ignore this failure intentionally
 });
 
 export class CollectionReference extends Query
@@ -2235,8 +2237,8 @@ export class CollectionReference extends Query
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
         'Invalid collection reference. Collection ' +
-        'references must have an odd number of segments, but ' +
-        `${path.canonicalString()} has ${path.length}`
+          'references must have an odd number of segments, but ' +
+          `${path.canonicalString()} has ${path.length}`
       );
     }
   }
@@ -2317,7 +2319,7 @@ function validateSetOptions(
     throw new FirestoreError(
       Code.INVALID_ARGUMENT,
       `Invalid options passed to function ${methodName}(): You cannot specify both "merge" ` +
-      `and "mergeFields".`
+        `and "mergeFields".`
     );
   }
 
diff --git a/packages/firestore/src/core/firestore_client.ts b/packages/firestore/src/core/firestore_client.ts
index 500593a7bbb..f3dbdcd85b6 100644
--- a/packages/firestore/src/core/firestore_client.ts
+++ b/packages/firestore/src/core/firestore_client.ts
@@ -74,14 +74,14 @@ export class IndexedDbPersistenceSettings {
   constructor(
     readonly cacheSizeBytes: number,
     readonly synchronizeTabs: boolean
-  ) { }
+  ) {}
 
   lruParams(): LruParams {
     return LruParams.withCacheSize(this.cacheSizeBytes);
   }
 }
 
-export class MemoryPersistenceSettings { }
+export class MemoryPersistenceSettings {}
 
 export type InternalPersistenceSettings =
   | IndexedDbPersistenceSettings
@@ -124,7 +124,7 @@ export class FirestoreClient {
      * an async I/O to complete).
      */
     private asyncQueue: AsyncQueue
-  ) { }
+  ) {}
 
   /**
    * Starts up the FirestoreClient, returning only whether or not enabling
@@ -253,8 +253,8 @@ export class FirestoreClient {
           }
           console.warn(
             'Error enabling offline persistence. Falling back to' +
-            ' persistence disabled: ' +
-            error
+              ' persistence disabled: ' +
+              error
           );
           return this.startMemoryPersistence();
         });
@@ -557,9 +557,9 @@ export class FirestoreClient {
           throw new FirestoreError(
             Code.UNAVAILABLE,
             'Failed to get document from cache. (However, this document may ' +
-            "exist on the server. Run again without setting 'source' in " +
-            'the GetOptions to attempt to retrieve the document from the ' +
-            'server.)'
+              "exist on the server. Run again without setting 'source' in " +
+              'the GetOptions to attempt to retrieve the document from the ' +
+              'server.)'
           );
         }
       });
@@ -611,7 +611,7 @@ export class FirestoreClient {
     this.verifyNotShutdown();
     // We have to wait for the async queue to be sure syncEngine is initialized.
     return this.asyncQueue
-      .enqueue(async () => { })
+      .enqueue(async () => {})
       .then(() => this.syncEngine.runTransaction(updateFunction));
   }
 }
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index b6d45b961c0..883ff321311 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -86,7 +86,7 @@ class DelayedOperation<T extends unknown> implements CancelablePromise<T> {
     // It's normal for the deferred promise to be canceled (due to cancellation)
     // and so we attach a dummy catch callback to avoid
     // 'UnhandledPromiseRejectionWarning' log spam.
-    this.deferred.promise.catch(err => { });
+    this.deferred.promise.catch(err => {});
   }
 
   /**
@@ -205,7 +205,9 @@ export class AsyncQueue {
 
   // Is this AsyncQueue being shutting down? If true, this instance will not enqueue
   // any new operations, Promises from enqueue requests will not resolve.
-  get isShuttingDown(): boolean { return this._isShuttingDown; }
+  get isShuttingDown(): boolean {
+    return this._isShuttingDown;
+  }
 
   /**
    * Adds a new operation to the queue without waiting for it to complete (i.e.
@@ -220,7 +222,9 @@ export class AsyncQueue {
    * Regardless if the queue has initialized shutdown, adds a new operation to the
    * queue without waiting for it to complete (i.e. we ignore the Promise result).
    */
-  enqueueAndForgetEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): void {
+  enqueueAndForgetEvenAfterShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): void {
     this.verifyNotFailed();
     // tslint:disable-next-line:no-floating-promises
     this.enqueueInternal(op);
@@ -230,7 +234,9 @@ export class AsyncQueue {
    * Regardless if the queue has initialized shutdown, adds a new operation to the
    * queue.
    */
-  private enqueueEvenAfterShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+  private enqueueEvenAfterShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): Promise<T> {
     this.verifyNotFailed();
     // tslint:disable-next-line:no-floating-promises
     return this.enqueueInternal(op);
@@ -243,11 +249,13 @@ export class AsyncQueue {
    * Once this method is called, the only possible way to request running an operation
    * is through `enqueueAndForgetEvenAfterShutdown`.
    */
-  enqueueAndInitilizeShutdown<T extends unknown>(op: () => Promise<T>): Promise<T> {
+  enqueueAndInitilizeShutdown<T extends unknown>(
+    op: () => Promise<T>
+  ): Promise<T> {
     this.verifyNotFailed();
     if (this._isShuttingDown) {
       // Return a Promise resolves right away if it is already shutdown.
-      return new Promise<T>((resolve) => resolve(undefined));
+      return new Promise<T>(resolve => resolve(undefined));
     }
 
     const promise = this.enqueueInternal(op);
@@ -263,7 +271,7 @@ export class AsyncQueue {
     this.verifyNotFailed();
     if (this._isShuttingDown) {
       // Return a Promise which never resolves.
-      return new Promise<T>((resolve) => {});
+      return new Promise<T>(resolve => {});
     }
     return this.enqueueInternal(op);
   }
@@ -341,7 +349,7 @@ export class AsyncQueue {
     if (this.failure) {
       fail(
         'AsyncQueue is already failed: ' +
-        (this.failure.stack || this.failure.message)
+          (this.failure.stack || this.failure.message)
       );
     }
   }
@@ -394,7 +402,7 @@ export class AsyncQueue {
     return this.drain().then(() => {
       assert(
         lastTimerId === TimerId.All ||
-        this.containsDelayedOperation(lastTimerId),
+          this.containsDelayedOperation(lastTimerId),
         `Attempted to drain to missing operation ${lastTimerId}`
       );
 
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index a8d317f90cc..8f8cf6103b7 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -962,7 +962,7 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  (persistence ? it: it.skip)(
+  (persistence ? it : it.skip)(
     'maintains persistence after restarting app',
     async () => {
       await withTestDoc(persistence, async docRef => {
@@ -1076,7 +1076,7 @@ apiDescribe('Database', (persistence: boolean) => {
 
       const newFirestore = firebase.firestore!(firestore.app);
       expect(newFirestore).to.not.equal(firestore);
-      await newFirestore.doc(docRef.path).set({foo: 'bar'});
+      await newFirestore.doc(docRef.path).set({ foo: 'bar' });
       const doc = await newFirestore.doc(docRef.path).get();
       expect(doc.data()).to.deep.equal({ foo: 'bar' });
     });
@@ -1087,7 +1087,7 @@ apiDescribe('Database', (persistence: boolean) => {
       await docRef.set({ foo: 'bar' });
       const app = docRef.firestore.app;
       await app.delete();
-      
+
       expect(docRef.firestore.INTERNAL.isShutdown()).to.be.true;
     });
   });
@@ -1098,7 +1098,7 @@ apiDescribe('Database', (persistence: boolean) => {
       await firestore.INTERNAL.shutdown();
 
       expect(() => {
-        firestore.doc(docRef.path).set({foo: 'bar'});
+        firestore.doc(docRef.path).set({ foo: 'bar' });
       }).to.throw();
     });
   });
@@ -1110,7 +1110,7 @@ apiDescribe('Database', (persistence: boolean) => {
       await firestore.INTERNAL.shutdown();
 
       expect(() => {
-        firestore.doc(docRef.path).set({foo: 'bar'});
+        firestore.doc(docRef.path).set({ foo: 'bar' });
       }).to.throw();
     });
   });

From 692dfa322c960dfc8e3d938c13ff9886721028f1 Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Thu, 1 Aug 2019 19:39:51 -0400
Subject: [PATCH 06/10] add settings for new instance

---
 packages/firestore/src/api/database.ts        | 27 +------------------
 .../test/integration/api/database.test.ts     | 10 ++++---
 2 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index 1c5e7dcaa81..6f45d6cb0ef 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -537,31 +537,6 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
     return this._config.firebaseApp;
   }
 
-  /**
-   * Shuts down this FirebaseFirestore instance.
-   *
-   * After shutdown only the `clearPersistence()` method may be used. Any other method
-   * will throw an `FirestoreError`.
-   *
-   * To restart after shutdown, simply create a new instance of FirebaseFirestore with
-   * `Firebase.firestore()`.
-   *
-   * Shutdown does not cancel any pending writes and any promises that are awaiting a response from
-   * the server will be resolved with `undefined`. The next time you start this instance, it will resume
-   * attempting to send these writes to the server.
-   *
-   * Note: Under normal circumstances, calling `shutdown()` is not required. This
-   * method is useful only when you want to force this instance to release all of its resources or
-   * in combination with `clearPersistence()` to ensure that all local state is destroyed
-   * between test runs.
-   *
-   * @return A promise that is resolved when the instance has been successfully shut down.
-   */
-  // TODO(b/135755126): make this public.
-  private shutdown(): Promise<void> {
-    return this.INTERNAL.delete();
-  }
-
   INTERNAL = {
     // TODO(b/135755126): Make this public
     delete: async (): Promise<void> => {
@@ -1078,7 +1053,7 @@ export class DocumentReference implements firestore.DocumentReference {
   }
 
   delete(): Promise<void> {
-    validateExactNumberOfArgs('FirebaseFirestore.shutdown', arguments, 0);
+    validateExactNumberOfArgs('FirebaseFirestore.delete', arguments, 0);
     return this._firestoreClient.write([
       new DeleteMutation(this._key, Precondition.NONE)
     ]);
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index 8f8cf6103b7..9f64447078b 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -21,7 +21,7 @@ import * as firestore from '@firebase/firestore-types';
 import { expect, use } from 'chai';
 
 import { SimpleDb } from '../../../src/local/simple_db';
-import { fail, assert } from '../../../src/util/assert';
+import { fail } from '../../../src/util/assert';
 import { Code } from '../../../src/util/error';
 import { query } from '../../util/api_helpers';
 import { Deferred } from '../../util/promise';
@@ -35,7 +35,8 @@ import {
   withTestDb,
   withTestDbs,
   withTestDoc,
-  withTestDocAndInitialData
+  withTestDocAndInitialData,
+  DEFAULT_SETTINGS
 } from '../util/helpers';
 
 // tslint:disable:no-floating-promises
@@ -1069,13 +1070,16 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  it.only('can start a new instance after shut down', async () => {
+  it('can start a new instance after shut down', async () => {
     return withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
       await firestore.INTERNAL.shutdown();
 
       const newFirestore = firebase.firestore!(firestore.app);
       expect(newFirestore).to.not.equal(firestore);
+
+      // New instance functions.
+      newFirestore.settings(DEFAULT_SETTINGS);
       await newFirestore.doc(docRef.path).set({ foo: 'bar' });
       const doc = await newFirestore.doc(docRef.path).get();
       expect(doc.data()).to.deep.equal({ foo: 'bar' });

From 1438df067150192d52aafd8950647a14799e9b04 Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Thu, 1 Aug 2019 19:59:32 -0400
Subject: [PATCH 07/10] final self review.

---
 packages/firestore/src/api/database.ts     | 2 +-
 packages/firestore/src/util/async_queue.ts | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index 6f45d6cb0ef..f825eb42ed4 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -1053,7 +1053,7 @@ export class DocumentReference implements firestore.DocumentReference {
   }
 
   delete(): Promise<void> {
-    validateExactNumberOfArgs('FirebaseFirestore.delete', arguments, 0);
+    validateExactNumberOfArgs('DocumentReference.delete', arguments, 0);
     return this._firestoreClient.write([
       new DeleteMutation(this._key, Precondition.NONE)
     ]);
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 883ff321311..75ed7c8acc0 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -188,7 +188,7 @@ export class AsyncQueue {
   // The last promise in the queue.
   private tail: Promise<unknown> = Promise.resolve();
 
-  // Is this AsyncQueue being shutting down? Once it is set to true, it will not
+  // Is this AsyncQueue being shut down? Once it is set to true, it will not
   // be changed again.
   private _isShuttingDown: boolean = false;
 
@@ -203,7 +203,7 @@ export class AsyncQueue {
   // assertion sanity-checks.
   private operationInProgress = false;
 
-  // Is this AsyncQueue being shutting down? If true, this instance will not enqueue
+  // Is this AsyncQueue being shut down? If true, this instance will not enqueue
   // any new operations, Promises from enqueue requests will not resolve.
   get isShuttingDown(): boolean {
     return this._isShuttingDown;

From eeec3899fb926065450859202392990cb6488158 Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Mon, 5 Aug 2019 21:58:50 -0400
Subject: [PATCH 08/10] addressing comments #1

---
 packages/firebase/index.d.ts                  |  6 +-
 packages/firestore-types/index.d.ts           |  6 +-
 packages/firestore/src/api/database.ts        | 66 +++++++++----------
 .../firestore/src/core/firestore_client.ts    |  2 +-
 packages/firestore/src/util/async_queue.ts    | 16 ++---
 .../test/integration/api/database.test.ts     | 10 +--
 .../test/unit/util/async_queue.test.ts        |  7 +-
 7 files changed, 48 insertions(+), 65 deletions(-)

diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 79e516c8938..28b43b2a311 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -6225,11 +6225,7 @@ declare namespace firebase.firestore {
     /**
      * @hidden
      */
-    INTERNAL: {
-      delete: () => Promise<void>;
-      shutdown: () => Promise<void>;
-      isShutdown: () => boolean;
-    };
+    INTERNAL: { delete: () => Promise<void> };
   }
 
   /**
diff --git a/packages/firestore-types/index.d.ts b/packages/firestore-types/index.d.ts
index eb66cd1830d..c96fa5925dc 100644
--- a/packages/firestore-types/index.d.ts
+++ b/packages/firestore-types/index.d.ts
@@ -276,11 +276,7 @@ export class FirebaseFirestore {
    */
   disableNetwork(): Promise<void>;
 
-  INTERNAL: {
-    delete: () => Promise<void>;
-    shutdown: () => Promise<void>;
-    isShutdown: () => boolean;
-  };
+  INTERNAL: { delete: () => Promise<void> };
 }
 
 /**
diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index f825eb42ed4..dbfe1fe7880 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -447,6 +447,39 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
     return deferred.promise;
   }
 
+  /**
+     * Shuts down this Firestore instance.
+     *
+     * After shutdown only the `clearPersistence()` method may be used. Any other method
+     * will throw a `FirestoreError`.
+     *
+     * To restart after shutdown, simply create a new instance of FirebaseFirestore with
+     * `firebase.firestore()`.
+     *
+     * Shutdown does not cancel any pending writes and any promises that are awaiting a response
+     * from the server will not be resolved. If you have persistence enabled, the next time you
+     * start this instance, it will resume attempting to send these writes to the server.
+     *
+     * Note: Under normal circumstances, calling `shutdown()` is not required. This
+     * method is useful only when you want to force this instance to release all of its resources or
+     * in combination with `clearPersistence()` to ensure that all local state is destroyed
+     * between test runs.
+     *
+     * @return A promise that is resolved when the instance has been successfully shut down.
+     */
+    // TODO(b/135755126): make this public.
+    _shutdown(): Promise<void> {
+      (this.app as _FirebaseApp)._removeServiceInstance(
+        'firestore'
+      );
+      return this.INTERNAL.delete();
+    }
+
+    get _isShutdown(): boolean {
+      this.ensureClientConfigured();
+      return this._firestoreClient!.clientShutdown;
+    }
+
   ensureClientConfigured(): FirestoreClient {
     if (!this._firestoreClient) {
       // Kick off starting the client but don't actually wait for it.
@@ -538,44 +571,11 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
   }
 
   INTERNAL = {
-    // TODO(b/135755126): Make this public
     delete: async (): Promise<void> => {
       // The client must be initalized to ensure that all subsequent API usage
       // throws an exception.
       this.ensureClientConfigured();
       await this._firestoreClient!.shutdown();
-    },
-
-    /**
-     * Shuts down this Firestore instance.
-     *
-     * After shutdown only the `clearPersistence()` method may be used. Any other method
-     * will throw an `FirestoreError`.
-     *
-     * To restart after shutdown, simply create a new instance of FirebaseFirestore with
-     * `Firebase.firestore()`.
-     *
-     * Shutdown does not cancel any pending writes and any promises that are awaiting a response
-     * from the server will not be resolved. The next time you start this instance,
-     * it will resume attempting to send these writes to the server.
-     *
-     * Note: Under normal circumstances, calling `shutdown()` is not required. This
-     * method is useful only when you want to force this instance to release all of its resources or
-     * in combination with `clearPersistence()` to ensure that all local state is destroyed
-     * between test runs.
-     *
-     * @return A promise that is resolved when the instance has been successfully shut down.
-     */
-    // TODO(b/135755126): make this public.
-    shutdown: (): Promise<void> => {
-      (this._config.firebaseApp as _FirebaseApp)._removeServiceInstance(
-        'firestore'
-      );
-      return this.INTERNAL.delete();
-    },
-
-    isShutdown: (): boolean => {
-      return this._firestoreClient!.clientShutdown;
     }
   };
 
diff --git a/packages/firestore/src/core/firestore_client.ts b/packages/firestore/src/core/firestore_client.ts
index f3dbdcd85b6..57df940ab1f 100644
--- a/packages/firestore/src/core/firestore_client.ts
+++ b/packages/firestore/src/core/firestore_client.ts
@@ -506,7 +506,7 @@ export class FirestoreClient {
   }
 
   shutdown(): Promise<void> {
-    return this.asyncQueue.enqueueAndInitilizeShutdown(async () => {
+    return this.asyncQueue.enqueueAndInitiateShutdown(async () => {
       // PORTING NOTE: LocalStore does not need an explicit shutdown on web.
       if (this.lruScheduler) {
         this.lruScheduler.stop();
diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 75ed7c8acc0..424ca0d9155 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -226,7 +226,6 @@ export class AsyncQueue {
     op: () => Promise<T>
   ): void {
     this.verifyNotFailed();
-    // tslint:disable-next-line:no-floating-promises
     this.enqueueInternal(op);
   }
 
@@ -238,7 +237,6 @@ export class AsyncQueue {
     op: () => Promise<T>
   ): Promise<T> {
     this.verifyNotFailed();
-    // tslint:disable-next-line:no-floating-promises
     return this.enqueueInternal(op);
   }
 
@@ -249,18 +247,12 @@ export class AsyncQueue {
    * Once this method is called, the only possible way to request running an operation
    * is through `enqueueAndForgetEvenAfterShutdown`.
    */
-  enqueueAndInitilizeShutdown<T extends unknown>(
-    op: () => Promise<T>
-  ): Promise<T> {
+  async enqueueAndInitiateShutdown(op: () => Promise<void>): Promise<void> {
     this.verifyNotFailed();
-    if (this._isShuttingDown) {
-      // Return a Promise resolves right away if it is already shutdown.
-      return new Promise<T>(resolve => resolve(undefined));
+    if (!this._isShuttingDown) {
+      this._isShuttingDown = true;
+      await this.enqueueEvenAfterShutdown(op);
     }
-
-    const promise = this.enqueueInternal(op);
-    this._isShuttingDown = true;
-    return promise;
   }
 
   /**
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index 9f64447078b..08d7dd4f54c 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -1073,7 +1073,7 @@ apiDescribe('Database', (persistence: boolean) => {
   it('can start a new instance after shut down', async () => {
     return withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await firestore.INTERNAL.shutdown();
+      await (firestore as any)._shutdown();
 
       const newFirestore = firebase.firestore!(firestore.app);
       expect(newFirestore).to.not.equal(firestore);
@@ -1092,14 +1092,14 @@ apiDescribe('Database', (persistence: boolean) => {
       const app = docRef.firestore.app;
       await app.delete();
 
-      expect(docRef.firestore.INTERNAL.isShutdown()).to.be.true;
+      expect((docRef.firestore as any)._isShutdown).to.be.true;
     });
   });
 
   it('new operation after shutdown should throw', async () => {
     await withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await firestore.INTERNAL.shutdown();
+      await (firestore as any)._shutdown();
 
       expect(() => {
         firestore.doc(docRef.path).set({ foo: 'bar' });
@@ -1110,8 +1110,8 @@ apiDescribe('Database', (persistence: boolean) => {
   it('calling shutdown mutiple times should proceed', async () => {
     await withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await firestore.INTERNAL.shutdown();
-      await firestore.INTERNAL.shutdown();
+      await (firestore as any)._shutdown();
+      await (firestore as any)._shutdown();
 
       expect(() => {
         firestore.doc(docRef.path).set({ foo: 'bar' });
diff --git a/packages/firestore/test/unit/util/async_queue.test.ts b/packages/firestore/test/unit/util/async_queue.test.ts
index bbf18694eea..265d37caa10 100644
--- a/packages/firestore/test/unit/util/async_queue.test.ts
+++ b/packages/firestore/test/unit/util/async_queue.test.ts
@@ -213,10 +213,9 @@ describe('AsyncQueue', () => {
   it('Schedules operaions with respect to shut down', async () => {
     const queue = new AsyncQueue();
     const completedSteps: number[] = [];
-    const doStep = (n: number): Promise<number> =>
+    const doStep = (n: number): Promise<void> =>
       defer(() => {
-        const result = completedSteps.push(n);
-        return result;
+        completedSteps.push(n);
       });
 
     queue.enqueueAndForget(() => doStep(1));
@@ -224,7 +223,7 @@ describe('AsyncQueue', () => {
     // After this call, only operations requested via
     // `enqueueAndForgetEvenAfterShutdown` gets executed.
     // tslint:disable-next-line:no-floating-promises
-    queue.enqueueAndInitilizeShutdown(() => doStep(2));
+    queue.enqueueAndInitiateShutdown(() => doStep(2));
     queue.enqueueAndForget(() => doStep(3));
     queue.enqueueAndForgetEvenAfterShutdown(() => doStep(4));
 

From 45c65a11ece180247e6ad999045069f2b4ba315c Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Mon, 5 Aug 2019 21:58:59 -0400
Subject: [PATCH 09/10] [AUTOMATED]: Prettier Code Styling

---
 packages/firestore/src/api/database.ts | 58 +++++++++++++-------------
 1 file changed, 28 insertions(+), 30 deletions(-)

diff --git a/packages/firestore/src/api/database.ts b/packages/firestore/src/api/database.ts
index dbfe1fe7880..fde7d73e6cc 100644
--- a/packages/firestore/src/api/database.ts
+++ b/packages/firestore/src/api/database.ts
@@ -448,37 +448,35 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
   }
 
   /**
-     * Shuts down this Firestore instance.
-     *
-     * After shutdown only the `clearPersistence()` method may be used. Any other method
-     * will throw a `FirestoreError`.
-     *
-     * To restart after shutdown, simply create a new instance of FirebaseFirestore with
-     * `firebase.firestore()`.
-     *
-     * Shutdown does not cancel any pending writes and any promises that are awaiting a response
-     * from the server will not be resolved. If you have persistence enabled, the next time you
-     * start this instance, it will resume attempting to send these writes to the server.
-     *
-     * Note: Under normal circumstances, calling `shutdown()` is not required. This
-     * method is useful only when you want to force this instance to release all of its resources or
-     * in combination with `clearPersistence()` to ensure that all local state is destroyed
-     * between test runs.
-     *
-     * @return A promise that is resolved when the instance has been successfully shut down.
-     */
-    // TODO(b/135755126): make this public.
-    _shutdown(): Promise<void> {
-      (this.app as _FirebaseApp)._removeServiceInstance(
-        'firestore'
-      );
-      return this.INTERNAL.delete();
-    }
+   * Shuts down this Firestore instance.
+   *
+   * After shutdown only the `clearPersistence()` method may be used. Any other method
+   * will throw a `FirestoreError`.
+   *
+   * To restart after shutdown, simply create a new instance of FirebaseFirestore with
+   * `firebase.firestore()`.
+   *
+   * Shutdown does not cancel any pending writes and any promises that are awaiting a response
+   * from the server will not be resolved. If you have persistence enabled, the next time you
+   * start this instance, it will resume attempting to send these writes to the server.
+   *
+   * Note: Under normal circumstances, calling `shutdown()` is not required. This
+   * method is useful only when you want to force this instance to release all of its resources or
+   * in combination with `clearPersistence()` to ensure that all local state is destroyed
+   * between test runs.
+   *
+   * @return A promise that is resolved when the instance has been successfully shut down.
+   */
+  // TODO(b/135755126): make this public.
+  _shutdown(): Promise<void> {
+    (this.app as _FirebaseApp)._removeServiceInstance('firestore');
+    return this.INTERNAL.delete();
+  }
 
-    get _isShutdown(): boolean {
-      this.ensureClientConfigured();
-      return this._firestoreClient!.clientShutdown;
-    }
+  get _isShutdown(): boolean {
+    this.ensureClientConfigured();
+    return this._firestoreClient!.clientShutdown;
+  }
 
   ensureClientConfigured(): FirestoreClient {
     if (!this._firestoreClient) {

From 59ea6b47133fca57cca7526e8ac0db4f4f15b3e4 Mon Sep 17 00:00:00 2001
From: Hui Wu <wuandy@google.com>
Date: Tue, 6 Aug 2019 15:20:33 -0400
Subject: [PATCH 10/10] address comments #2

---
 packages/firestore/src/util/async_queue.ts             |  1 +
 .../firestore/test/integration/api/database.test.ts    | 10 ++++++----
 packages/firestore/test/integration/util/helpers.ts    |  5 +++++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/packages/firestore/src/util/async_queue.ts b/packages/firestore/src/util/async_queue.ts
index 424ca0d9155..680807e58be 100644
--- a/packages/firestore/src/util/async_queue.ts
+++ b/packages/firestore/src/util/async_queue.ts
@@ -226,6 +226,7 @@ export class AsyncQueue {
     op: () => Promise<T>
   ): void {
     this.verifyNotFailed();
+    // tslint:disable-next-line:no-floating-promises
     this.enqueueInternal(op);
   }
 
diff --git a/packages/firestore/test/integration/api/database.test.ts b/packages/firestore/test/integration/api/database.test.ts
index 08d7dd4f54c..651514d7cdb 100644
--- a/packages/firestore/test/integration/api/database.test.ts
+++ b/packages/firestore/test/integration/api/database.test.ts
@@ -31,6 +31,7 @@ import {
   apiDescribe,
   arrayContainsAnyOp,
   inOp,
+  shutdownDb,
   withTestCollection,
   withTestDb,
   withTestDbs,
@@ -1073,7 +1074,7 @@ apiDescribe('Database', (persistence: boolean) => {
   it('can start a new instance after shut down', async () => {
     return withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await (firestore as any)._shutdown();
+      await shutdownDb(firestore);
 
       const newFirestore = firebase.firestore!(firestore.app);
       expect(newFirestore).to.not.equal(firestore);
@@ -1092,6 +1093,7 @@ apiDescribe('Database', (persistence: boolean) => {
       const app = docRef.firestore.app;
       await app.delete();
 
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       expect((docRef.firestore as any)._isShutdown).to.be.true;
     });
   });
@@ -1099,7 +1101,7 @@ apiDescribe('Database', (persistence: boolean) => {
   it('new operation after shutdown should throw', async () => {
     await withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await (firestore as any)._shutdown();
+      await shutdownDb(firestore);
 
       expect(() => {
         firestore.doc(docRef.path).set({ foo: 'bar' });
@@ -1110,8 +1112,8 @@ apiDescribe('Database', (persistence: boolean) => {
   it('calling shutdown mutiple times should proceed', async () => {
     await withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
-      await (firestore as any)._shutdown();
-      await (firestore as any)._shutdown();
+      await shutdownDb(firestore);
+      await shutdownDb(firestore);
 
       expect(() => {
         firestore.doc(docRef.path).set({ foo: 'bar' });
diff --git a/packages/firestore/test/integration/util/helpers.ts b/packages/firestore/test/integration/util/helpers.ts
index dab836d6b28..786412e57d4 100644
--- a/packages/firestore/test/integration/util/helpers.ts
+++ b/packages/firestore/test/integration/util/helpers.ts
@@ -303,6 +303,11 @@ function wipeDb(db: firestore.FirebaseFirestore): Promise<void> {
   return Promise.resolve(undefined);
 }
 
+export function shutdownDb(db: firestore.FirebaseFirestore): Promise<void> {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  return (db as any)._shutdown();
+}
+
 // TODO(in-queries): This exists just so we don't have to do the cast
 // repeatedly. Once we expose 'array-contains-any' publicly we can remove it and
 // just use 'array-contains-any' in all the tests.