feat(listCollections): add support for nameOnly option

Fixes NODE-1471

Author: daprahamian

lib/db.js

@@ -455,8 +455,10 @@ Db.prototype.collection = function(name, options, callback) {
     return callback(new MongoError('topology was destroyed'));
   }
 
+  const listCollectionOptions = Object.assign({}, options, { nameOnly: true });
+
   // Strict mode
-  this.listCollections({ name: name }, options).toArray(function(err, collections) {
+  this.listCollections({ name: name }, listCollectionOptions).toArray(function(err, collections) {
     if (err != null) return handleCallback(callback, err, null);
     if (collections.length === 0)
       return handleCallback(
@@ -486,9 +488,11 @@ var createCollection = function(self, name, options, callback) {
     return callback(new MongoError('topology was destroyed'));
   }
 
+  const listCollectionOptions = Object.assign({}, finalOptions, { nameOnly: true });
+
   // Check if we have the name
   self
-    .listCollections({ name: name }, finalOptions)
+    .listCollections({ name: name }, listCollectionOptions)
     .setReadPreference(ReadPreference.PRIMARY)
     .toArray(function(err, collections) {
       if (err != null) return handleCallback(callback, err, null);
@@ -653,6 +657,7 @@ var listCollectionsTranforms = function(databaseName) {
  * @method
  * @param {object} [filter={}] Query to filter collections by
  * @param {object} [options=null] Optional settings.
+ * @param {boolean} [options.nameOnly=false] Since 4.0: If true, will only return the collection name in the response, and will omit additional info
  * @param {number} [options.batchSize=null] The batchSize for the returned command cursor or if pre 2.8 the systems batch collection
  * @param {(ReadPreference|string)} [options.readPreference=null] The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST).
  * @param {ClientSession} [options.session] optional session to use for this operation
@@ -678,8 +683,10 @@ Db.prototype.listCollections = function(filter, options) {
   if (this.serverConfig.capabilities().hasListCollectionsCommand) {
     // Cursor options
     var cursor = options.batchSize ? { batchSize: options.batchSize } : {};
+
+    const nameOnly = typeof options.nameOnly === 'boolean' ? options.nameOnly : false;
     // Build the command
-    var command = { listCollections: true, filter: filter, cursor: cursor };
+    var command = { listCollections: true, filter, cursor, nameOnly };
     // Set the AggregationCursor constructor
     options.cursorFactory = CommandCursor;
     // Create the cursor
@@ -917,6 +924,7 @@ Db.prototype.collections = function(options, callback) {
 };
 
 var collections = function(self, options, callback) {
+  options = Object.assign({}, options, { nameOnly: true });
   // Let's get the collection names
   self.listCollections({}, options).toArray(function(err, documents) {
     if (err != null) return handleCallback(callback, err, null);

test/unit/db_list_collections_tests.js

@@ -0,0 +1,86 @@
+'use strict';
+
+const mock = require('mongodb-mock-server');
+const expect = require('chai').expect;
+const MongoClient = require('../../lib/mongo_client');
+
+describe('db.listCollections', function() {
+  const testHarness = {};
+  afterEach(() => mock.cleanup());
+  beforeEach(() => {
+    return mock.createServer().then(server => {
+      server.setMessageHandler(request => {
+        const doc = request.document;
+
+        if (doc.ismaster) {
+          return request.reply(Object.assign({}, mock.DEFAULT_ISMASTER));
+        }
+
+        if (doc.listCollections) {
+          return request.reply({
+            ok: 1,
+            cursor: {
+              id: 0,
+              ns: 'test.$cmd.listCollections',
+              firstBatch: [{ name: 'test', type: 'collection' }]
+            }
+          });
+        }
+      });
+      testHarness.server = server;
+    });
+  });
+
+  [
+    {
+      description: 'should always send nameOnly option, defaulting to false',
+      command: db => db.listCollections().toArray(() => {}),
+      listCollectionsValue: false
+    },
+    {
+      description: 'should propagate the nameOnly option',
+      command: db => db.listCollections({}, { nameOnly: true }).toArray(() => {}),
+      listCollectionsValue: true
+    },
+    {
+      description: 'should send nameOnly: true for db.createCollection',
+      command: db => db.createCollection('foo', () => {}),
+      listCollectionsValue: true
+    },
+    {
+      description: 'should send nameOnly: true for db.collections',
+      command: db => db.collections(() => {}),
+      listCollectionsValue: true
+    },
+    {
+      description: 'should send nameOnly: true for db.collection',
+      command: db => db.collection('foo', { strict: true }, () => {}),
+      listCollectionsValue: true
+    }
+  ].forEach(config => {
+    function testFn(done) {
+      const client = new MongoClient(`mongodb://${testHarness.server.uri()}/test`, {
+        monitorCommands: true
+      });
+
+      client.connect((err, client) => {
+        const db = client.db('foo');
+
+        client.on('commandStarted', e => {
+          if (e.commandName === 'listCollections') {
+            try {
+              expect(e).to.have.nested.property('command.nameOnly', config.listCollectionsValue);
+              client.close(done);
+            } catch (err) {
+              client.close(() => done(err));
+            }
+          }
+        });
+
+        config.command(db);
+      });
+    }
+
+    it(config.description, { test: testFn, metadata: { requires: { mongodb: '>=2.7.6' } } });
+  });
+});