How to mock event handler method using sinon.js?

I am newbie to Node.js and I am writing DAO layer for HBase which will wrap thrift and provide clear interface to other layers. I am trying to write unit tests for it using sinon.js and mocha but not sure how to ensure mock one event of Thrift connection class and its event handler.

My DAO code is as follows:

var thrift = require('thrift');
var libDirRelativePath = "../../../lib";
var hbaseThriftDirPath = libDirRelativePath + "/hbase-gen-nodejs";
var hbase = require(hbaseThriftDirPath + '/THBaseService');
var hbaseTypes = require(hbaseThriftDirPath + '/hbase_types');

var thritfPrimaryServerAddress = 'nn2';
var thritfBackupServerAddress = 'backup-nn2';
var thriftServerPort = 9090;

exports.putRows = function(tableName, putObjectArray, callback) {
    var primaryClusterConnection = thrift.createConnection(thritfPrimaryServerAddress, thriftServerPort, {
      transport: thrift.TBufferedTransport,
      protocol : thrift.TBinaryProtocol
    });

    console.log('DEBUG : connection object created.');

    var client = thrift.createClient(hbase, primaryClusterConnection);
    console.log('DEBUG : client object created.');

    primaryClusterConnection.on('connect', onConnectOfPutRows);

    primaryClusterConnection.on('connect', function() {
        console.log('Connected to HBase thrift server at ' + thritfPrimaryServerAddress + ":" + thriftServerPort);
        client.putMultiple(tableName, putObjectArray, callback);
        connection.close();
    });

    primaryClusterConnection.on('error', function() {
        console.log('Error occurred in HBase thirft server connection.');
    });
}

For above code I Just want to create stubs primaryClusterConnection and client objects which I have managed but problem is that stub of primaryClusterConnection doesn't have any idea about connect event and its handler so console.log('Connected to HBase thrift server at '... line never gets executed. I want to test that part of the code as well. Can anyone please help me in writing proper stubs/mocks for this problem?

My test code is as follows:

var hbaseDao = require('../../../src/dao/hbase/HBaseDao.js');
var libDirRelativePath = "../../../lib";
var hbaseThriftDirPath = libDirRelativePath + "/hbase-gen-nodejs";
var hbase = require(hbaseThriftDirPath + '/THBaseService');

var chai = require('chai');
var should = chai.should();
var expect = chai.expect;
var sinon = require('sinon');

describe("HBaseDao", function() {
    describe(".putRows()", function() {

        it("Should execute callback after inserting objects in HBase.", function(done) {
            var commonStub = sinon.stub();
            var connection = {
                close : function() {
                    console.log('connection closed.');
                }
            };
            commonStub.withArgs('nn2', 9090).returns(connection);
            var client = {};
            commonStub.withArgs(hbase, connection).returns(client);
            var tableName = 'DUMMY_READINGS_TABLE';
            var callBackMethod = function() {
                console.log('dummy callback function.');
            };
            commonStub.withArgs(tableName, [], callBackMethod).returns(0);

            hbaseDao.putRows(tableName, [], callBackMethod);
            expect(hbaseDaoSpy.callCount).to.equal(1);
            done();
        });