How can I unit test the request response cycle in Node.js? - unit-testing

Question

For example suppose I have the following
app.get('/', function(req, res) {
var ip;
if(req.headers['x-forwarded-for']){
ip = req.headers['x-forwarded-for'];
}
else {
ip = req.connection.remoteAddress;
}
});
I would like to unit test to see whether ip is being properly retrieved. One way is as follows
function getIp(req) {
var ip;
if(req.headers['x-forwarded-for']){
ip = req.headers['x-forwarded-for'];
}
else {
ip = req.connection.remoteAddress;
}
return ip;
}
app.get('/', function(req, res) {
var ip = getIp(req);
});
Now I have a function getIp that I can unit test. However I'm still stuck. How can I feed a simulated req object into getIp?

Answer 1

I would just write integration-tests for that. Node.js is fast enough for that. Especially when you use something like Mocha's watch-mode. You could use something like superagent or request to perform http requests.
There is also something like for example nock to mock out your http requests. Although I have never used it because integration-tests test the real thing and are fast enough for my tast.

Answer 2

I'd recommend using mocha to write your unit tests in which case you'll use 'request' as your http client. But the simplest way to get started is to use the following:
var http = require('http');
//Change to the ip:port of your server
var client = http.createClient(3000, 'localhost');
var request = client.request('GET', '/',
{'host': 'localhost'});
request.end();
request.on('response', function (response) {
console.log('STATUS: ' + response.statusCode);
console.log('HEADERS: ' + JSON.stringify(response.headers));
response.setEncoding('utf8');
response.on('data', function (chunk) {
console.log('BODY: ' + chunk);
});
});