From f4f35cbba673e7063691865074d17d392af6228a Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna.henningsen@mongodb.com>
Date: Fri, 14 May 2021 18:56:06 +0200
Subject: [PATCH] feat(shell-api): add mongo.getDBs() and .getDBNames()
 MONGOSH-766
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These were present in the legacy shell, and while they were
undocumented, I feel like they are obvious candidates for inclusion
in the API, so I’m just going ahead and opening a PR.
---
 packages/i18n/src/locales/en_US.ts         |  9 +++++++++
 packages/shell-api/src/integration.spec.ts | 12 ++++++++++++
 packages/shell-api/src/mongo.ts            | 20 ++++++++++++++++----
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/packages/i18n/src/locales/en_US.ts b/packages/i18n/src/locales/en_US.ts
index 87c16c2c46..4106b5d79b 100644
--- a/packages/i18n/src/locales/en_US.ts
+++ b/packages/i18n/src/locales/en_US.ts
@@ -1660,6 +1660,15 @@ const translations: Catalog = {
               link: 'https://docs.mongodb.com/manual/reference/method/Mongo.getDB',
               description: 'Returns the specified Database of the Mongo object.'
             },
+            getDBs: {
+              link: 'https://docs.mongodb.com/manual/reference/method/Mongo.getDBs',
+              description: 'Returns information about all databases. Uses the listDatabases command.'
+            },
+            getDBNames: {
+              link: 'https://docs.mongodb.com/manual/reference/method/Mongo.getDBs',
+              description: 'Returns an array of all database names. Uses the listDatabases command.',
+              example: 'db.getMongo().getDBNames().map(name => db.getSiblingDB(name).getCollectionNames())'
+            },
             connect: {
               link: 'https://docs.mongodb.com/manual/reference/method/connect',
               description: 'Creates a connection to a MongoDB instance and returns the reference to the database.'
diff --git a/packages/shell-api/src/integration.spec.ts b/packages/shell-api/src/integration.spec.ts
index f0f5a0e071..374059875e 100644
--- a/packages/shell-api/src/integration.spec.ts
+++ b/packages/shell-api/src/integration.spec.ts
@@ -1744,6 +1744,18 @@ describe('Shell API (integration)', function() {
         expect(internalState.mongos).to.deep.equal([mongo]);
       });
     });
+    describe('getDBs', () => {
+      it('lists all databases', async() => {
+        const result = await mongo.getDBs();
+        expect(result.ok).to.equal(1);
+        expect(result.databases.find(db => db.name === 'admin').sizeOnDisk).to.be.a('number');
+      });
+    });
+    describe('getDBNames', () => {
+      it('lists all database names', async() => {
+        expect(await mongo.getDBNames()).to.include('admin');
+      });
+    });
   });
   describe('PlanCache', () => {
     describe('list', () => {
diff --git a/packages/shell-api/src/mongo.ts b/packages/shell-api/src/mongo.ts
index 23da7a757a..c9ba0eb0d3 100644
--- a/packages/shell-api/src/mongo.ts
+++ b/packages/shell-api/src/mongo.ts
@@ -218,7 +218,7 @@ export default class Mongo extends ShellApiClass {
     return `switched to db ${db}`;
   }
 
-  async _listDatabases(opts: ListDatabasesOptions = {}): Promise<{name: string, sizeOnDisk: number, empty: boolean}[]> {
+  async _listDatabases(opts: ListDatabasesOptions = {}): Promise<{ databases: {name: string, sizeOnDisk: number, empty: boolean}[] }> {
     const result = await this._serviceProvider.listDatabases('admin', { ...opts });
     if (!('databases' in result)) {
       const err = new MongoshRuntimeError('Got invalid result from "listDatabases"', CommonErrors.CommandFailed);
@@ -226,13 +226,13 @@ export default class Mongo extends ShellApiClass {
       throw err;
     }
     this._cachedDatabaseNames = result.databases.map((db: any) => db.name);
-    return result.databases;
+    return result as any;
   }
 
   async _getDatabaseNamesForCompletion(): Promise<string[]> {
     return await Promise.race([
       (async() => {
-        return (await this._listDatabases({ readPreference: 'primaryPreferred' })).map(db => db.name);
+        return (await this._listDatabases({ readPreference: 'primaryPreferred' })).databases.map(db => db.name);
       })(),
       (async() => {
         // See the comment in _getCollectionNamesForCompletion/database.ts
@@ -243,6 +243,18 @@ export default class Mongo extends ShellApiClass {
     ]);
   }
 
+  @returnsPromise
+  async getDBs(options: ListDatabasesOptions = {}): Promise<{ databases: {name: string, sizeOnDisk: number, empty: boolean}[] }> {
+    this._emitMongoApiCall('getDBs', { options });
+    return await this._listDatabases(options);
+  }
+
+  @returnsPromise
+  async getDBNames(options: ListDatabasesOptions = {}): Promise<string[]> {
+    this._emitMongoApiCall('getDBNames', { options });
+    return (await this._listDatabases(options)).databases.map(db => db.name);
+  }
+
   @returnsPromise
   async show(cmd: string, arg?: string): Promise<CommandResult> {
     this._internalState.messageBus.emit('mongosh:show', { method: `show ${cmd}` });
@@ -250,7 +262,7 @@ export default class Mongo extends ShellApiClass {
     switch (cmd) {
       case 'databases':
       case 'dbs':
-        const result = await this._listDatabases({ readPreference: 'primaryPreferred' });
+        const result = (await this._listDatabases({ readPreference: 'primaryPreferred' })).databases;
         return new CommandResult('ShowDatabasesResult', result);
       case 'collections':
       case 'tables':