firebase · dconeybe · May 1, 2023 · Mar 31, 2023 · Apr 12, 2023 · Apr 13, 2023
diff --git a/.changeset/witty-wasps-play.md b/.changeset/witty-wasps-play.md
@@ -0,0 +1,6 @@
+---
+'@firebase/firestore': minor
+'firebase': minor
+---
+
+Added the ability to configure the long-polling hanging get request timeout using the new `idleHttpRequestTimeoutSeconds` setting
diff --git a/common/api-review/firestore.api.md b/common/api-review/firestore.api.md
@@ -184,6 +184,11 @@ export function endBefore(snapshot: DocumentSnapshot<unknown>): QueryEndAtConstr
 // @public
 export function endBefore(...fieldValues: unknown[]): QueryEndAtConstraint;
 
+// @public
+export interface ExperimentalLongPollingOptions {
+    timeoutSeconds?: number;
+}
+
 // @public
 export class FieldPath {
     constructor(...fieldNames: string[]);
@@ -227,6 +232,7 @@ export interface FirestoreSettings {
     cacheSizeBytes?: number;
     experimentalAutoDetectLongPolling?: boolean;
     experimentalForceLongPolling?: boolean;
+    experimentalLongPollingOptions?: ExperimentalLongPollingOptions;
     host?: string;
     ignoreUndefinedProperties?: boolean;
     localCache?: FirestoreLocalCache;

diff --git a/docs-devsite/firestore_.experimentallongpollingoptions.md b/docs-devsite/firestore_.experimentallongpollingoptions.md
@@ -0,0 +1,43 @@
+Project: /docs/reference/js/_project.yaml
+Book: /docs/reference/_book.yaml
+page_type: reference
+
+{% comment %}
+DO NOT EDIT THIS FILE!
+This is generated by the JS SDK team, and any local changes will be
+overwritten. Changes should be made in the source code at
+https://github.com/firebase/firebase-js-sdk
+{% endcomment %}
+
+# ExperimentalLongPollingOptions interface
+Options that configure the SDK’s underlying network transport (WebChannel) when long-polling is used.
+
+Note: This interface is "experimental" and is subject to change.
+
+See `FirestoreSettings.experimentalAutoDetectLongPolling`<!-- -->, `FirestoreSettings.experimentalForceLongPolling`<!-- -->, and `FirestoreSettings.experimentalLongPollingOptions`<!-- -->.
+
+<b>Signature:</b>
+
+```typescript
+export declare interface ExperimentalLongPollingOptions 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [timeoutSeconds](./firestore_.experimentallongpollingoptions.md#experimentallongpollingoptionstimeoutseconds) | number | The desired maximum timeout interval, in seconds, to complete a long-polling GET response. Valid values are between 5 and 30, inclusive. Floating point values are allowed and will be rounded to the nearest millisecond.<!-- -->By default, when long-polling is used the "hanging GET" request sent by the client times out after 30 seconds. To request a different timeout from the server, set this setting with the desired timeout.<!-- -->Changing the default timeout may be useful, for example, if the buffering proxy that necessitated enabling long-polling in the first place has a shorter timeout for hanging GET requests, in which case setting the long-polling timeout to a shorter value, such as 25 seconds, may fix prematurely-closed hanging GET requests. For example, see https://github.com/firebase/firebase-js-sdk/issues/6987. |
+
+## ExperimentalLongPollingOptions.timeoutSeconds
+
+The desired maximum timeout interval, in seconds, to complete a long-polling GET response. Valid values are between 5 and 30, inclusive. Floating point values are allowed and will be rounded to the nearest millisecond.
+
+By default, when long-polling is used the "hanging GET" request sent by the client times out after 30 seconds. To request a different timeout from the server, set this setting with the desired timeout.
+
+Changing the default timeout may be useful, for example, if the buffering proxy that necessitated enabling long-polling in the first place has a shorter timeout for hanging GET requests, in which case setting the long-polling timeout to a shorter value, such as 25 seconds, may fix prematurely-closed hanging GET requests. For example, see https://github.com/firebase/firebase-js-sdk/issues/6987.
+
+<b>Signature:</b>
+
+```typescript
+timeoutSeconds?: number;
+```
diff --git a/docs-devsite/firestore_.firestoresettings.md b/docs-devsite/firestore_.firestoresettings.md
@@ -25,6 +25,7 @@ export declare interface FirestoreSettings
 |  [cacheSizeBytes](./firestore_.firestoresettings.md#firestoresettingscachesizebytes) | number | NOTE: This field will be deprecated in a future major release. Use <code>cache</code> field instead to specify cache size, and other cache configurations.<!-- -->An approximate cache size threshold for the on-disk data. If the cache grows beyond this size, Firestore will start removing data that hasn't been recently used. The size is not a guarantee that the cache will stay below that size, only that if the cache exceeds the given size, cleanup will be attempted.<!-- -->The default value is 40 MB. The threshold must be set to at least 1 MB, and can be set to <code>CACHE_SIZE_UNLIMITED</code> to disable garbage collection. |
 |  [experimentalAutoDetectLongPolling](./firestore_.firestoresettings.md#firestoresettingsexperimentalautodetectlongpolling) | boolean | Configures the SDK's underlying transport (WebChannel) to automatically detect if long-polling should be used. This is very similar to <code>experimentalForceLongPolling</code>, but only uses long-polling if required.<!-- -->This setting will likely be enabled by default in future releases and cannot be combined with <code>experimentalForceLongPolling</code>. |
 |  [experimentalForceLongPolling](./firestore_.firestoresettings.md#firestoresettingsexperimentalforcelongpolling) | boolean | Forces the SDK’s underlying network transport (WebChannel) to use long-polling. Each response from the backend will be closed immediately after the backend sends data (by default responses are kept open in case the backend has more data to send). This avoids incompatibility issues with certain proxies, antivirus software, etc. that incorrectly buffer traffic indefinitely. Use of this option will cause some performance degradation though.<!-- -->This setting cannot be used with <code>experimentalAutoDetectLongPolling</code> and may be removed in a future release. If you find yourself using it to work around a specific network reliability issue, please tell us about it in https://github.com/firebase/firebase-js-sdk/issues/1674. |
+|  [experimentalLongPollingOptions](./firestore_.firestoresettings.md#firestoresettingsexperimentallongpollingoptions) | [ExperimentalLongPollingOptions](./firestore_.experimentallongpollingoptions.md#experimentallongpollingoptions_interface) | Options that configure the SDK’s underlying network transport (WebChannel) when long-polling is used.<!-- -->These options are only used if <code>experimentalForceLongPolling</code> is true or if <code>experimentalAutoDetectLongPolling</code> is true and the auto-detection determined that long-polling was needed. Otherwise, these options have no effect. |
 |  [host](./firestore_.firestoresettings.md#firestoresettingshost) | string | The hostname to connect to. |
 |  [ignoreUndefinedProperties](./firestore_.firestoresettings.md#firestoresettingsignoreundefinedproperties) | boolean | Whether to skip nested properties that are set to <code>undefined</code> during object serialization. If set to <code>true</code>, these properties are skipped and not written to Firestore. If set to <code>false</code> or omitted, the SDK throws an exception when it encounters properties of type <code>undefined</code>. |
 |  [localCache](./firestore_.firestoresettings.md#firestoresettingslocalcache) | [FirestoreLocalCache](./firestore_.md#firestorelocalcache) | Specifies the cache used by the SDK. Available options are <code>MemoryLocalCache</code> and <code>IndexedDbLocalCache</code>, each with different configuration options.<!-- -->When unspecified, <code>MemoryLocalCache</code> will be used by default.<!-- -->NOTE: setting this field and <code>cacheSizeBytes</code> at the same time will throw exception during SDK initialization. Instead, using the configuration in the <code>FirestoreLocalCache</code> object to specify the cache size. |
@@ -68,6 +69,18 @@ This setting cannot be used with `experimentalAutoDetectLongPolling` and may be
 experimentalForceLongPolling?: boolean;
 ```
 
+## FirestoreSettings.experimentalLongPollingOptions
+
+Options that configure the SDK’s underlying network transport (WebChannel) when long-polling is used.
+
+These options are only used if `experimentalForceLongPolling` is true or if `experimentalAutoDetectLongPolling` is true and the auto-detection determined that long-polling was needed. Otherwise, these options have no effect.
+
+<b>Signature:</b>
+
+```typescript
+experimentalLongPollingOptions?: ExperimentalLongPollingOptions;
+```
+
 ## FirestoreSettings.host
 
 The hostname to connect to.

diff --git a/docs-devsite/firestore_.md b/docs-devsite/firestore_.md
@@ -149,6 +149,7 @@ https://github.com/firebase/firebase-js-sdk
 |  [AggregateSpec](./firestore_.aggregatespec.md#aggregatespec_interface) | Specifies a set of aggregations and their aliases. |
 |  [DocumentChange](./firestore_.documentchange.md#documentchange_interface) | A <code>DocumentChange</code> represents a change to the documents matching a query. It contains the document affected and the type of change that occurred. |
 |  [DocumentData](./firestore_.documentdata.md#documentdata_interface) | Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->) consists of fields mapped to values. |
+|  [ExperimentalLongPollingOptions](./firestore_.experimentallongpollingoptions.md#experimentallongpollingoptions_interface) | Options that configure the SDK’s underlying network transport (WebChannel) when long-polling is used.<!-- -->Note: This interface is "experimental" and is subject to change.<!-- -->See <code>FirestoreSettings.experimentalAutoDetectLongPolling</code>, <code>FirestoreSettings.experimentalForceLongPolling</code>, and <code>FirestoreSettings.experimentalLongPollingOptions</code>. |
 |  [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface) | Converter used by <code>withConverter()</code> to transform user objects of type <code>T</code> into Firestore data.<!-- -->Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore. |
 |  [FirestoreSettings](./firestore_.firestoresettings.md#firestoresettings_interface) | Specifies custom configurations for your Cloud Firestore instance. You must set these before invoking any other methods. |
 |  [Index](./firestore_.index.md#index_interface) | <b><i>(BETA)</i></b> The SDK definition of a Firestore index. |

diff --git a/packages/firestore/src/api.ts b/packages/firestore/src/api.ts
@@ -82,6 +82,7 @@ export {
 } from './api/bundle';
 
 export { FirestoreSettings, PersistenceSettings } from './api/settings';
+export { ExperimentalLongPollingOptions } from './api/long_polling_options';
 
 export {
   DocumentChange,

diff --git a/packages/firestore/src/api/long_polling_options.ts b/packages/firestore/src/api/long_polling_options.ts
@@ -0,0 +1,73 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Options that configure the SDK’s underlying network transport (WebChannel)
+ * when long-polling is used.
+ *
+ * Note: This interface is "experimental" and is subject to change.
+ *
+ * See `FirestoreSettings.experimentalAutoDetectLongPolling`,
+ * `FirestoreSettings.experimentalForceLongPolling`, and
+ * `FirestoreSettings.experimentalLongPollingOptions`.
+ */
+export interface ExperimentalLongPollingOptions {
+  /**
+   * The desired maximum timeout interval, in seconds, to complete a
+   * long-polling GET response. Valid values are between 5 and 30, inclusive.
+   * Floating point values are allowed and will be rounded to the nearest
+   * millisecond.
+   *
+   * By default, when long-polling is used the "hanging GET" request sent by
+   * the client times out after 30 seconds. To request a different timeout
+   * from the server, set this setting with the desired timeout.
+   *
+   * Changing the default timeout may be useful, for example, if the buffering
+   * proxy that necessitated enabling long-polling in the first place has a
+   * shorter timeout for hanging GET requests, in which case setting the
+   * long-polling timeout to a shorter value, such as 25 seconds, may fix
+   * prematurely-closed hanging GET requests.
+   * For example, see https://github.com/firebase/firebase-js-sdk/issues/6987.
+   */
+  timeoutSeconds?: number;
+}
+
+/**
+ * Compares two `ExperimentalLongPollingOptions` objects for equality.
+ */
+export function longPollingOptionsEqual(
+  options1: ExperimentalLongPollingOptions,
+  options2: ExperimentalLongPollingOptions
+): boolean {
+  return options1.timeoutSeconds === options2.timeoutSeconds;
+}
+
+/**
+ * Creates and returns a new `ExperimentalLongPollingOptions` with the same
+ * option values as the given instance.
+ */
+export function cloneLongPollingOptions(
+  options: ExperimentalLongPollingOptions
+): ExperimentalLongPollingOptions {
+  const clone: ExperimentalLongPollingOptions = {};
+
+  if (options.timeoutSeconds !== undefined) {
+    clone.timeoutSeconds = options.timeoutSeconds;
+  }
+
+  return clone;
+}
diff --git a/packages/firestore/src/api/settings.ts b/packages/firestore/src/api/settings.ts
@@ -18,6 +18,7 @@
 import { FirestoreSettings as LiteSettings } from '../lite-api/settings';
 
 import { FirestoreLocalCache } from './cache_config';
+import { ExperimentalLongPollingOptions } from './long_polling_options';
 
 export { DEFAULT_HOST } from '../lite-api/settings';
 
@@ -92,4 +93,15 @@ export interface FirestoreSettings extends LiteSettings {
    * cannot be combined with `experimentalForceLongPolling`.
    */
   experimentalAutoDetectLongPolling?: boolean;
+
+  /**
+   * Options that configure the SDK’s underlying network transport (WebChannel)
+   * when long-polling is used.
+   *
+   * These options are only used if `experimentalForceLongPolling` is true or if
+   * `experimentalAutoDetectLongPolling` is true and the auto-detection
+   * determined that long-polling was needed. Otherwise, these options have no
+   * effect.
+   */
+  experimentalLongPollingOptions?: ExperimentalLongPollingOptions;
 }
diff --git a/packages/firestore/src/core/database_info.ts b/packages/firestore/src/core/database_info.ts
@@ -1,5 +1,6 @@
 import { FirebaseApp } from '@firebase/app';
 
+import { ExperimentalLongPollingOptions } from '../api/long_polling_options';
 import { Code, FirestoreError } from '../util/error';
 
 /**
@@ -34,6 +35,7 @@ export class DatabaseInfo {
    * when using WebChannel as the network transport.
    * @param autoDetectLongPolling - Whether to use the detectBufferingProxy
    * option when using WebChannel as the network transport.
+   * @param longPollingOptions Options that configure long-polling.
    * @param useFetchStreams Whether to use the Fetch API instead of
    * XMLHTTPRequest
    */
@@ -45,6 +47,7 @@ export class DatabaseInfo {
     readonly ssl: boolean,
     readonly forceLongPolling: boolean,
     readonly autoDetectLongPolling: boolean,
+    readonly longPollingOptions: ExperimentalLongPollingOptions,
     readonly useFetchStreams: boolean
   ) {}
 }

diff --git a/packages/firestore/src/lite-api/components.ts b/packages/firestore/src/lite-api/components.ts
@@ -19,6 +19,7 @@
 import { _FirebaseService } from '@firebase/app';
 
 import { CredentialsProvider } from '../api/credentials';
+import { cloneLongPollingOptions } from '../api/long_polling_options';
 import { User } from '../auth/user';
 import { DatabaseId, DatabaseInfo } from '../core/database_info';
 import { newConnection } from '../platform/connection';
@@ -117,6 +118,7 @@ export function makeDatabaseInfo(
     settings.ssl,
     settings.experimentalForceLongPolling,
     settings.experimentalAutoDetectLongPolling,
+    cloneLongPollingOptions(settings.experimentalLongPollingOptions),
     settings.useFetchStreams
   );
 }
diff --git a/packages/firestore/src/lite-api/settings.ts b/packages/firestore/src/lite-api/settings.ts
@@ -17,6 +17,11 @@
 
 import { FirestoreLocalCache } from '../api/cache_config';
 import { CredentialsSettings } from '../api/credentials';
+import {
+  ExperimentalLongPollingOptions,
+  cloneLongPollingOptions,
+  longPollingOptionsEqual
+} from '../api/long_polling_options';
 import {
   LRU_COLLECTION_DISABLED,
   LRU_DEFAULT_CACHE_SIZE_BYTES
@@ -29,6 +34,18 @@ import { validateIsNotUsedTogether } from '../util/input_validation';
 export const DEFAULT_HOST = 'firestore.googleapis.com';
 export const DEFAULT_SSL = true;
 
+// The minimum long-polling timeout is hardcoded on the server. The value here
+// should be kept in sync with the value used by the server, as the server will
+// silently ignore a value below the minimum and fall back to the default.
+// Googlers see b/266868871 for relevant discussion.
+const MIN_LONG_POLLING_TIMEOUT_SECONDS = 5;
+
+// No maximum long-polling timeout is configured in the server, and defaults to
+// 30 seconds, which is what Watch appears to use.
+// Googlers see b/266868871 for relevant discussion.
+const MAX_LONG_POLLING_TIMEOUT_SECONDS = 30;
+
+// Whether long-polling auto-detected is enabled by default.
 const DEFAULT_AUTO_DETECT_LONG_POLLING = false;
 
 /**
@@ -58,6 +75,7 @@ export interface PrivateSettings extends FirestoreSettings {
   cacheSizeBytes?: number;
   experimentalForceLongPolling?: boolean;
   experimentalAutoDetectLongPolling?: boolean;
+  experimentalLongPollingOptions?: ExperimentalLongPollingOptions;
   useFetchStreams?: boolean;
 
   localCache?: FirestoreLocalCache;
@@ -81,6 +99,8 @@ export class FirestoreSettingsImpl {
 
   readonly experimentalAutoDetectLongPolling: boolean;
 
+  readonly experimentalLongPollingOptions: ExperimentalLongPollingOptions;
+
   readonly ignoreUndefinedProperties: boolean;
 
   readonly useFetchStreams: boolean;
@@ -146,6 +166,11 @@ export class FirestoreSettingsImpl {
         !!settings.experimentalAutoDetectLongPolling;
     }
 
+    this.experimentalLongPollingOptions = cloneLongPollingOptions(
+      settings.experimentalLongPollingOptions ?? {}
+    );
+    validateLongPollingOptions(this.experimentalLongPollingOptions);
+
     this.useFetchStreams = !!settings.useFetchStreams;
   }
 
@@ -159,8 +184,40 @@ export class FirestoreSettingsImpl {
         other.experimentalForceLongPolling &&
       this.experimentalAutoDetectLongPolling ===
         other.experimentalAutoDetectLongPolling &&
+      longPollingOptionsEqual(
+        this.experimentalLongPollingOptions,
+        other.experimentalLongPollingOptions
+      ) &&
       this.ignoreUndefinedProperties === other.ignoreUndefinedProperties &&
       this.useFetchStreams === other.useFetchStreams
     );
   }
 }
+
+function validateLongPollingOptions(
+  options: ExperimentalLongPollingOptions
+): void {
+  if (options.timeoutSeconds !== undefined) {
+    if (isNaN(options.timeoutSeconds)) {
+      throw new FirestoreError(
+        Code.INVALID_ARGUMENT,
+        `invalid long polling timeout: ` +
+          `${options.timeoutSeconds} (must not be NaN)`
+      );
+    }
+    if (options.timeoutSeconds < MIN_LONG_POLLING_TIMEOUT_SECONDS) {
+      throw new FirestoreError(
+        Code.INVALID_ARGUMENT,
+        `invalid long polling timeout: ${options.timeoutSeconds} ` +
+          `(minimum allowed value is ${MIN_LONG_POLLING_TIMEOUT_SECONDS})`
+      );
+    }
+    if (options.timeoutSeconds > MAX_LONG_POLLING_TIMEOUT_SECONDS) {
+      throw new FirestoreError(
+        Code.INVALID_ARGUMENT,
+        `invalid long polling timeout: ${options.timeoutSeconds} ` +
+          `(maximum allowed value is ${MAX_LONG_POLLING_TIMEOUT_SECONDS})`
+      );
+    }
+  }
+}