Wait for Express.js app starting before running tests

app.js

var express = require('express');
var data = require('./source/data');

var app = express();
var port = process.env.PORT || 3036;

data.boot(env, function (err) {
	if (err) {
		app.emit('error', err);
		throw err;
	}

	app.listen(port, function () {
		app.emit('ready');
	});
});

module.exports = app;

runTests.js

process.env.NODE_ENV = process.env.NODE_ENV || 'test';
process.env.TEST_ENV = process.env.TEST_ENV || 'test';

var exit = process.exit;
process.exit = function (code) {
	setTimeout(function () {
		exit();
	}, 200);
};

// start server
var app = require('../app');

console.log('booting up service, please wait...');

app.on('ready', function () {
	// run tests
	require('../node_modules/mocha/bin/_mocha');
});

app.on('error', function (e) {
	console.error(e);
	process.exit(-1);
});