fix(shell-api): use primaryPreferred for show commands

People don’t necessarily expect `show` to follow the same rules as
other shell calls, and expect it to work even when connected to a
secondary. Use `primaryPreferred` as the read preference for
`show db`/`show collections` to address this.
(This is a deviation from the old shell’s behavior.)

Author: addaleax

packages/cli-repl/test/e2e-direct.spec.ts

@@ -1,5 +1,6 @@
 import { startTestCluster } from '../../../testing/integration-testing-hooks';
 import { eventually } from './helpers';
+import { expect } from 'chai';
 import { TestShell } from './test-shell';
 
 describe('e2e direct connection', () => {
@@ -94,6 +95,14 @@ describe('e2e direct connection', () => {
           await shell.executeLine('db.runCommand({ listCollections: 1 })');
           shell.assertContainsOutput("name: 'system.version'");
         });
+
+        it('lists collections and dbs using show by default', async() => {
+          const shell = TestShell.start({ args: [`${await rs1.connectionString()}`] });
+          await shell.waitForPrompt();
+          await shell.executeLine('use admin');
+          expect(await shell.executeLine('show collections')).to.include('system.version');
+          expect(await shell.executeLine('show dbs')).to.include('admin');
+        });
       });
 
       context('connecting to primary', () => {
@@ -122,6 +131,14 @@ describe('e2e direct connection', () => {
           shell.assertContainsOutput(`me: '${await rs0.hostport()}'`);
           shell.assertContainsOutput(`setName: '${replSetId}'`);
         });
+
+        it('lists collections and dbs using show by default', async() => {
+          const shell = TestShell.start({ args: [`${await rs1.connectionString()}`] });
+          await shell.waitForPrompt();
+          await shell.executeLine('use admin');
+          expect(await shell.executeLine('show collections')).to.include('system.version');
+          expect(await shell.executeLine('show dbs')).to.include('admin');
+        });
       });
     });
   });

packages/java-shell/src/main/kotlin/com/mongodb/mongosh/service/AdminServiceProvider.kt

@@ -6,7 +6,7 @@ import org.graalvm.polyglot.Value
  * see service-provider-core/src/admin.ts
  */
 internal interface AdminServiceProvider {
-    fun listDatabases(database: String): Value
+    fun listDatabases(database: String, options: Value?): Value
     fun getNewConnection(uri: String, options: Value?): Value
     fun getConnectionInfo(): Value
     fun authenticate(authDoc: Value): Value

packages/java-shell/src/main/kotlin/com/mongodb/mongosh/service/JavaServiceProvider.kt

@@ -438,7 +438,7 @@ internal class JavaServiceProvider(private val client: MongoClient,
     }
 
     @HostAccess.Export
-    override fun listDatabases(database: String): Value = promise {
+    override fun listDatabases(database: String, options: Value?): Value = promise {
         Right(mapOf("databases" to client.listDatabases()))
     }
 

packages/service-provider-core/src/admin.ts

@@ -8,7 +8,8 @@ import type {
   CreateCollectionOptions,
   ClientSession,
   DbOptions,
-  ClientSessionOptions
+  ClientSessionOptions,
+  ListDatabasesOptions
 } from './all-transport-types';
 import type { bson as BSON } from './index';
 import { ReplPlatform } from './platform';
@@ -37,7 +38,7 @@ export default interface Admin {
    *
    * @returns {Promise} The promise of command Documents.
    */
-  listDatabases(database: string): Promise<Document>;
+  listDatabases(database: string, options?: ListDatabasesOptions): Promise<Document>;
 
   /**
    * create a new service provider with a new connection.

packages/service-provider-server/src/cli-service-provider.ts

@@ -841,8 +841,9 @@ class CliServiceProvider extends ServiceProviderCore implements ServiceProvider
    *
    * @returns {Promise} The promise of command results.
    */
-  listDatabases(database: string): Promise<Document> {
-    return this.db(database).admin().listDatabases(this.baseCmdOptions as ListDatabasesOptions);
+  listDatabases(database: string, options: ListDatabasesOptions = {}): Promise<Document> {
+    options = { ...this.baseCmdOptions, ...options };
+    return this.db(database).admin().listDatabases(options);
   }
 
   /**

packages/shell-api/src/database.ts

@@ -141,8 +141,8 @@ export default class Database extends ShellApiClass {
     ) || [];
   }
 
-  async _getCollectionNames(): Promise<string[]> {
-    const infos = await this._listCollections({}, { nameOnly: true });
+  async _getCollectionNames(options?: ListCollectionsOptions): Promise<string[]> {
+    const infos = await this._listCollections({}, { ...options, nameOnly: true });
     this._cachedCollectionNames = infos.map((collection: any) => collection.name);
     return this._cachedCollectionNames;
   }

packages/shell-api/src/mongo.spec.ts

@@ -116,22 +116,24 @@ describe('Mongo', () => {
         describe(t, () => {
           it('calls database.getCollectionNames', async() => {
             const expectedResult = ['a', 'b'];
-            database.getCollectionNames.resolves(expectedResult);
+            database._getCollectionNames.resolves(expectedResult);
             await mongo.show(t);
-            expect(database.getCollectionNames).to.have.been.calledWith();
+            expect(database._getCollectionNames).to.have.been.calledWith({
+              readPreference: 'primaryPreferred'
+            });
           });
 
           it('returns ShowCollectionsResult CommandResult', async() => {
             const expectedResult = ['a', 'b'];
-            database.getCollectionNames.resolves(expectedResult);
+            database._getCollectionNames.resolves(expectedResult);
             const result = await mongo.show(t);
             expect(result.value).to.deep.equal(expectedResult);
             expect(result.type).to.equal('ShowCollectionsResult');
           });
 
           it('throws if database.getCollectionNames rejects', async() => {
             const expectedError = new Error();
-            database.getCollectionNames.rejects(expectedError);
+            database._getCollectionNames.rejects(expectedError);
             const catchedError = await mongo.show(t)
               .catch(e => e);
             expect(catchedError).to.equal(expectedError);

packages/shell-api/src/mongo.ts

@@ -145,12 +145,12 @@ export default class Mongo extends ShellApiClass {
 
   @returnsPromise
   async show(cmd: string, arg?: string): Promise<CommandResult> {
-    this._internalState.messageBus.emit( 'mongosh:show', { method: `show ${cmd}` });
+    this._internalState.messageBus.emit('mongosh:show', { method: `show ${cmd}` });
 
     switch (cmd) {
       case 'databases':
       case 'dbs':
-        const result = await this._serviceProvider.listDatabases('admin');
+        const result = await this._serviceProvider.listDatabases('admin', { readPreference: 'primaryPreferred' });
         if (!('databases' in result)) {
           const err = new MongoshRuntimeError('Got invalid result from "listDatabases"', CommonErrors.CommandFailed);
           this._internalState.messageBus.emit('mongosh:error', err);
@@ -160,7 +160,7 @@ export default class Mongo extends ShellApiClass {
         return new CommandResult('ShowDatabasesResult', result.databases);
       case 'collections':
       case 'tables':
-        const collectionNames = await this._internalState.currentDb.getCollectionNames();
+        const collectionNames = await this._internalState.currentDb._getCollectionNames({ readPreference: 'primaryPreferred' });
         return new CommandResult('ShowCollectionsResult', collectionNames);
       case 'profile':
         const sysprof = this._internalState.currentDb.getCollection('system.profile');