CODEWITHSUNDEEP
node.jstesting
mjs
mjs

Reputation: 65373

How to create a mock http.ServerRequest and http.ServerResponse?

I've written a handler for http.Server's request event (i.e. a function with signature function (request, response) { ... }) and I'd like to test it. I'd like to do this via mock http.ServerRequest and http.ServerResponse objects. How can I create these?

The obvious way doesn't seem to work:

$ node
> var http = require('http');
> new http.ServerRequest();
TypeError: undefined is not a function
    at repl:1:9
...

Do I need to test this via a "real" HTTP server and client?

Upvotes: 0

Views: 5317

Answers (3)

Daithí
Daithí

Reputation: 4079

I created a simple and basic mock for http.ServerResponse, the gist is here and for http.ServerRequest I use rewire.

Firstly load dependencies:

var require = require('rewire'),
    events = require('events'),
    util = require('util');

This is the http.ServerResponse mock. It basically creates an object with the same methods as http.ServerResponse, and then the events module is inherited using the util module.

/**
 * Mock https.serverResponse
 * @type {Object}
 */
var mockResponse;
Eventer = function(){
    events.EventEmitter.call(this);

    this.data = '';

    this.onData = function(){
        this.emit('data', this.data);
    }

    this.setEncoding = function(){

    }

    this.onEnd = function(){
        this.emit('end', this.data);
    }

    this.run = function(){
        this.onData();
        this.onEnd();
    }
};
util.inherits(Eventer, events.EventEmitter);

I then use this mock with rewire to override the http module's get(), request() or any other library.

/**
 * Mocks literal object for rewire mocking.
 * @see https://github.com/jhnns/rewire
 * @type {Object}
 */
var mocks = {
    "https" : {
        "get" : function(url, fn){
            fn(mockResponse.data);
            mockResponse.run();
        }
    }
};

//instead of: var myModule = require('myModule');
//do:
var myModule = rewire('myModule');
myModule.__set__(mocks);

Now the http library in your module is mocked

Upvotes: 0

mjs
mjs

Reputation: 65373

There's at least two projects that allow mocking of http.ServerRequest and http.ServerResponse: https://github.com/howardabrams/node-mocks-http and https://github.com/vojtajina/node-mocks.

And for some reason it does seem to be more common to test via real HTTP request; https://github.com/flatiron/nock seems to be the tool to use here.

See also node.js: Mock http request and response.

Upvotes: 4

user568109
user568109

Reputation: 48013

Yes, you can do it using http.request. It allows you to issue requests from server, so you can test it with your code. If you want to send simple GET request you can use http.get , which is easier. Otherwise you would have to construct your request yourself. Example from docs :

var options = {
  host: 'www.google.com',
  port: 80,
  path: '/upload',
  method: 'POST'
};

var req = http.request(options, function(res) {
  res.setEncoding('utf8');
  console.log('STATUS: ' + res.statusCode);
  res.on('data', function (chunk) {
    console.log('BODY: ' + chunk);
  });
});

req.on('error', function(e) {
  console.log('problem with request: ' + e.message);
});

req.write('data\n');
req.end();

If you are using request you can do the same.

var request = require('request');
request.post( url, json_obj_to_pass,
    function (error, response, body) {
        if (!error && response.statusCode == 200)
            console.log(body)
    }
);

Upvotes: 0

Related Questions