Setup/teardown of express.js application with mocha - node.js

Question

I'm trying to create a standalone test suite using mocha, that in a perfect world would start up my express.js application, use zombie to render a page, check a bunch of stuff and then teardown/kill the express.js application.
Is there an easy/best way to do this?
NB. I could just have the express application server running prior to running the tests, but what good are Yaks if you're not going to shave them.

Answer 1

First, you need to move your actual app setting up into a module, and import that into the file that actually starts your app. Now that this is seperate, you can have the app in its complete state before actually listening.
You should move the actual setting up of your app into a separate file, let's call it app.js, can call listen from the file you run node off of, let's call it index.js.
So, app.js would look like:
var express = require('express')
, routes = require('./routes');
var app = module.exports = express.createServer();
// Configuration
app.configure(function(){
app.set('views', __dirname + '/views');
app.set('view engine', 'jade');
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(__dirname + '/public'));
});
app.configure('development', function(){
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
});
app.configure('production', function(){
app.use(express.errorHandler());
});
// Routes
app.get('/', routes.index);
and index.js would look like:
var app = require('./app');
app.listen(3000, function(){
console.log("Express server listening on port %d in %s mode", app.address().port, app.settings.env);
});
This seperates loading of your app from actually having it listen, allowing you to load that app into your unit tests.
In your unit tests, you would do something in a setup method and teardown method to bring up and bring down the server.
In the file test/app_tests.js:
describe('app', function(){
var app = require('../app');
beforeEach(function(){
app.listen(3000);
});
// tests here
afterEach(function(){
app.close();
})
});

Answer 2

In addition to Oved D answer.
Describe your app in express-app.js or some other file:
module.exports = function (o) {
o = o || {};
var app = express();
// app.configure
// configure routes
if (o.someOption) {
// some additional test code
}
return app;
}
describe tests in test/01-some.js:
var expressApp = require('../express-app');
describe('some', function () {
// just describe needed vars
var app, server, port;
// describe setup
before(function (next) {
// create app when
app = expressApp({routes: /api\/some\/.*/ /* put here some test options ...*/});
// creating listener with random port
server = app.listen(function () {
// store port when it ready
port = server.address().port;
// and go to tests
next();
});
});
// tests
it('should return valid result', function (done) {
// do a simple request to /api/some
http.request({
host: 'localhost',
port: port,
path: '/api/some'
}, function (res) {
if (res.err) throw new Error(res.err);
done();
});
});
// teardown
after(function () {
// stop listening that port
server.close();
});
});
Done. ;-)
Now you can create any count of tests like that. Recommend you to enable only needed urls and services in tests with defining it by passing params to express-app.js module.
Update:
Not sure how it works in mocha but better to move before and after calls to init.js and load it with mocha --require init.js.
File should looks like that:
// use it in your mocha tests
global.setupEnv = function setupEnv (o, before, after) {
// just describe needed vars
var env = Object.create(null);
// setup
before(function (next) {
// create app
env.app = expressApp(o);
// creating listener with random port
env.server = env.app.listen(function () {
// store port when it ready
port = env.server.address().port;
env.app.log('Listening on ', env.port);
// and go to tests
next();
});
});
// teardown
after(function () {
// stop listening that port
env.server.close();
});
return env;
}
And in your tests:
// requiring dependencies
var request = require('request');
describe('api', function () {
// describe setup
var env = global.setupEnv({
routes: 'api/some'
}, before, after);
// tests
it('should pass', function (done) {
request('http://localhost:' + env.port, function (error, response, body) {
done();
});
});
});