feat: Support for using multiple databases in datastore

package.json

@@ -59,6 +59,7 @@
     "@types/node": "^20.4.9",
     "@types/proxyquire": "^1.3.28",
     "@types/sinon": "^10.0.0",
+    "async": "^3.2.4",
     "c8": "^8.0.1",
     "gapic-tools": "^0.2.0",
     "gts": "^5.0.0",

src/index.ts

@@ -700,6 +700,16 @@ class Datastore extends DatastoreRequest {
     );
   }
 
+  /**
+   * Gets the database id that all requests will be run against.
+   *
+   * @returns {string} The database id that the current client is set to that
+   *    requests will run against.
+   */
+  getDatabaseId(): string | undefined {
+    return this.options.databaseId;
+  }
+
   getProjectId(): Promise<string> {
     return this.auth.getProjectId();
   }
@@ -1818,6 +1828,7 @@ promisifyAll(Datastore, {
     'double',
     'isDouble',
     'geoPoint',
+    'getDatabaseId',
     'getProjectId',
     'isGeoPoint',
     'index',
@@ -1898,6 +1909,7 @@ export interface DatastoreOptions extends GoogleAuthOptions {
   namespace?: string;
   apiEndpoint?: string;
   sslCreds?: ChannelCredentials;
+  databaseId?: string;
 }
 
 export interface KeyToLegacyUrlSafeCallback {

src/request.ts

@@ -44,7 +44,7 @@
   KeyProto,
   ResponseResult,
   Entities,
   ValueProto,
 } from './entity';
 import {
   Query,
@@ -596,9 +596,9 @@
           const results = res.batch.aggregationResults;
           const finalResults = results
             .map(
               (aggregationResult: any) => aggregationResult.aggregateProperties
             )
             .map((aggregateProperties: any) =>
               Object.fromEntries(
                 new Map(
                   Object.keys(aggregateProperties).map(key => [
@@ -933,7 +933,7 @@
     callback?: SaveCallback
   ): void | Promise<CommitResponse> {
     const transaction = this.datastore.transaction();
     transaction.run(async (err: any) => {
       if (err) {
         try {
           await transaction.rollback();
@@ -992,6 +992,10 @@
       }
     }
 
+    if (datastore.options && datastore.options.databaseId) {
+      reqOpts.databaseId = datastore.options.databaseId;
+    }
+
     if (method === 'rollback') {
       reqOpts.transaction = this.id;
     }
@@ -1143,6 +1147,7 @@
   reqOpts?: RequestOptions;
 }
 export interface SharedQueryOptions {
+  databaseId?: string;
   projectId?: string;
   partitionId?: google.datastore.v1.IPartitionId | null;
   readOptions?: {