add option to merge settings

.changeset/mean-jokes-tan.md

@@ -0,0 +1,7 @@
+---
+'firebase': patch
+'@firebase/firestore': patch
+'@firebase/firestore-types': patch
+---
+
+feat: Added `inherit` setting to merge existing settings with new settings when calling `firestore.settings()`.

packages/firebase/index.d.ts

@@ -7758,10 +7758,18 @@ declare namespace firebase.firestore {
     /**
      * Whether to skip nested properties that are set to `undefined` during
      * object serialization. If set to `true`, these properties are skipped
-     * and not written to Firestore. If set `false` or omitted, the SDK throws
-     * an exception when it encounters properties of type `undefined`.
+     * and not written to Firestore. If set to `false` or omitted, the SDK
+     * throws an exception when it encounters properties of type `undefined`.
      */
     ignoreUndefinedProperties?: boolean;
+
+    /**
+     * Whether to merge the provided settings with the existing settings. If
+     * set to `true`, the settings will be merged with existing settings. If
+     * set to `false` or left unset, the settings will replace the existing
+     * settings.
+     */
+    inherit?: boolean;
   }
 
   /**

packages/firestore-types/index.d.ts

@@ -30,6 +30,7 @@ export interface Settings {
   cacheSizeBytes?: number;
   experimentalForceLongPolling?: boolean;
   ignoreUndefinedProperties?: boolean;
+  inherit?: boolean;
 }
 
 export interface PersistenceSettings {

packages/firestore/src/api/database.ts

@@ -363,6 +363,12 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
     validateExactNumberOfArgs('Firestore.settings', arguments, 1);
     validateArgType('Firestore.settings', 'object', 1, settingsLiteral);
 
+    if (settingsLiteral.inherit) {
+      settingsLiteral = this.mergeSettings(settingsLiteral);
+      // Remove the property from the settings once the merge is completed.
+      delete settingsLiteral.inherit;
+    }
+
     const newSettings = new FirestoreSettings(settingsLiteral);
     if (this._firestoreClient && !this._settings.isEqual(newSettings)) {
       throw new FirestoreError(
@@ -379,6 +385,33 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
     }
   }
 
+  private mergeSettings(
+    settingsLiteral: firestore.Settings
+  ): firestore.Settings {
+    settingsLiteral.host =
+      settingsLiteral.host === undefined
+        ? this._settings.host
+        : settingsLiteral.host;
+    settingsLiteral.ssl =
+      settingsLiteral.ssl === undefined
+        ? this._settings.ssl
+        : settingsLiteral.ssl;
+    settingsLiteral.timestampsInSnapshots =
+      settingsLiteral.timestampsInSnapshots === undefined
+        ? this._settings.timestampsInSnapshots
+        : settingsLiteral.timestampsInSnapshots;
+    settingsLiteral.cacheSizeBytes =
+      settingsLiteral.cacheSizeBytes === undefined
+        ? this._settings.cacheSizeBytes
+        : settingsLiteral.cacheSizeBytes;
+    settingsLiteral.ignoreUndefinedProperties =
+      settingsLiteral.ignoreUndefinedProperties === undefined
+        ? this._settings.ignoreUndefinedProperties
+        : settingsLiteral.ignoreUndefinedProperties;
+
+    return settingsLiteral;
+  }
+
   enableNetwork(): Promise<void> {
     this.ensureClientConfigured();
     return this._firestoreClient!.enableNetwork();
@@ -674,6 +707,11 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
   _areTimestampsInSnapshotsEnabled(): boolean {
     return this._settings.timestampsInSnapshots;
   }
+
+  // Visible for testing.
+  _getSettings(): firestore.Settings {
+    return this._settings;
+  }
 }
 
 /** Registers the listener for onSnapshotsInSync() */

packages/firestore/test/integration/api/database.test.ts

@@ -1219,7 +1219,7 @@ apiDescribe('Database', (persistence: boolean) => {
     });
   });
 
-  it('calling terminate mutiple times should proceed', async () => {
+  it('calling terminate multiple times should proceed', async () => {
     await withTestDoc(persistence, async docRef => {
       const firestore = docRef.firestore;
       await firestore.terminate();

packages/firestore/test/unit/api/database.test.ts

@@ -19,10 +19,12 @@ import {
   collectionReference,
   documentReference,
   documentSnapshot,
+  namedFirestore,
   query,
   querySnapshot
 } from '../../util/api_helpers';
 import { expectEqual, expectNotEqual, keys } from '../../util/helpers';
+import { expect } from 'chai';
 
 describe('CollectionReference', () => {
   it('support equality checking with isEqual()', () => {
@@ -153,3 +155,31 @@ describe('SnapshotMetadata', () => {
     );
   });
 });
+
+describe('Settings', () => {
+  it('replaces settings by default', () => {
+    // Use a new instance of Firestore in order to configure settings.
+    const firestoreClient = namedFirestore('new-project');
+    firestoreClient.settings({ host: 'other.host' });
+    firestoreClient.settings({ ignoreUndefinedProperties: true });
+
+    expect(firestoreClient._getSettings().ignoreUndefinedProperties).to.be.true;
+    // Expect host to be replaced with default host.
+    expect(firestoreClient._getSettings().host).to.equal(
+      'firestore.googleapis.com'
+    );
+  });
+
+  it('can merge settings', () => {
+    // Use a new instance of Firestore in order to configure settings.
+    const firestoreClient = namedFirestore('new-project');
+    firestoreClient.settings({ host: 'other.host' });
+    firestoreClient.settings({
+      ignoreUndefinedProperties: true,
+      inherit: true
+    });
+
+    expect(firestoreClient._getSettings().ignoreUndefinedProperties).to.be.true;
+    expect(firestoreClient._getSettings().host).to.equal('other.host');
+  });
+});

packages/firestore/test/util/api_helpers.ts

@@ -57,6 +57,17 @@ export function firestore(): Firestore {
   return FIRESTORE;
 }
 
+export function namedFirestore(projectId: string): Firestore {
+  return new Firestore(
+    {
+      projectId,
+      database: '(default)'
+    },
+    new Provider('auth-internal', new ComponentContainer('default')),
+    new MultiTabIndexedDbComponentProvider()
+  );
+}
+
 export function collectionReference(path: string): CollectionReference {
   const firestoreClient = firestore();
   // eslint-disable-next-line @typescript-eslint/no-floating-promises