ExpressJS Archives - Development Thoughts & Findings

MEAN Stack – Full Test Sample Application

August 28, 2015

Reading Time: 1 minute

In order to help the development community at large, I thought I’d push out the app that I had used in my write up for testing the MEAN stack. You can check it out on github here: https://github.com/SBero/mean-todo

It still has some work needing to be done to it, but enough is currently done to help others get started with fully testing their MEAN apps.

I’d like to get it to the point, where it’s the perfect sample project for someone new to the MEAN stack to be able to review, pick up some best practices and see exactly how to do the testing that’s involved (especially testing all of the isolate scope parts of an AngularJS directive!).

Unit Testing Full Stack Part 1 – node/io.js with express

April 6, 2015

Reading Time: 2 minutes

This is going to be a multi-part series of posts to detail my current process for unit testing a full stack javascript application. Consider this my brain dump of information that I’ve either found from others posts, found in the official documentation or I’ve just been doing it that way because it makes sense in my head.

Unit testing has to be one of the most important aspects for any developer that’s serious about their work to start doing, and be disciplined enough to continue doing it regardless of some of the mind-numbing aspects of it.

Starting off we will be establishing the testing procedure for our javascript backend, which consists of node/io.js using express to serve up our restful api. I was shocked once I finally got everything working properly, with how easy it was to get going.

You will need to npm install the following modules:

mocha
supertest
chai

# npm install -g mocha
# npm install --save-dev supertest chai

1 2	# npm install -g mocha # npm install --save-dev supertest chai

These are the only modules necessary to do all your assertion/expect testing.

Once installed, I would suggest creating a test folder at the root of your application directory. Inside of this directory I will typically split groups of tests for each Controller in my application. Ending up with something like this:

/my-express-app
  /controllers
  /database
  /test
    /unit
      /fixtures
      myControllerSpec.js

/my-express-app

/controllers

/database

/test

/unit

/fixtures

myControllerSpec.js

The controller specs should be setup something like this:

var request = require('supertest'),
    express = require('express'),
    chai = require('chai');

var expect = chai.expect;

var app = require ('../app.js'); // path must be relative to current file.

describe('Unit: UserController', function(){
    var resource = 'user';

    describe('GET /user', function(){
  
        it('responds with all the users and status code 200', function(done){
            request(app)
                .get('/' + resource)
                .end(function(err, res){
                    expect(res.statusCode.to.equal(200);
                    expect(res.body.user).to.be.defined;
                    done();
            });
        });
    });
});

var request = require('supertest'),

express = require('express'),

chai = require('chai');

var expect = chai.expect;

var app = require ('../app.js'); // path must be relative to current file.

describe('Unit: UserController', function(){

var resource = 'user';

describe('GET /user', function(){

it('responds with all the users and status code 200', function(done){

request(app)

.get('/' + resource)

.end(function(err, res){

expect(res.statusCode.to.equal(200);

expect(res.body.user).to.be.defined;

done();

});

Now with that setup, you can just run from your project root, from the command line:

mocha -w test/unit/**/*.js

1	mocha -w test/unit/*/.js

and it will watch all test files for changes and run all your tests again, if a change is detected.

That’s all there is to it for getting true automatic testing going for your existing or next express api.

The next post will be for how to properly setup testing for the angular end of your application.

Node, Express and { [Error: socket hang up] code: ‘ECONNRESET’ }

March 29, 2015

Reading Time: 1 minute

I’m not sure how many scenarios this issue would crop up in, but I wanted to at least post about the one that I found:

{ [Error: socket hang up] code: 'ECONNRESET'}

1	{ [Error: socket hang up] code: 'ECONNRESET'}

This happens on my iojs/express api that I’m working on, and trying to do a file upload test with mocha and supertest.

If you are doing something like this:

request(app)
    .post('/upload')
    .attach('file', 'fixtures/photo.jpg')
    .send({'key':'value'})
    .end(function(){...});

request(app)

.post('/upload')

.attach('file', 'fixtures/photo.jpg')

.send({'key':'value'})

.end(function(){...});

.attach() is not compatible with .send().

You need to remove .send() and put that data into .field() function calls like this:

.post('/upload')
.field('user_id', 1)
.field('detail', {...})
.attach('file', __dirname + '/fixtures/photo.jpg')
.end(...)

.post('/upload')

.field('user_id', 1)

.field('detail', {...})

.attach('file', __dirname + '/fixtures/photo.jpg')

.end(...)

Doing this completely resolved the { [Error: socket hang up] code: ‘ECONNRESET’} error that I was receiving.

Hope this helps anyone with the same issue.

Node/ExpressJS Can’t Set Headers Bug…Possible solution

February 1, 2015

Reading Time: 1 minute

I was working on some of my more complex project aspects today, after spending an entire weekend setting up, and building out most of my applications unit and end-to-end tests when I noticed this issue when I moved onto the new build features inside of the Angular app:

Possibly unhandled Error: Can’t set headers after they are sent.

I’m scouring the code EVERYWHERE. How is this possible? According to my unit tests, I have code coverage across all of these functions with literally every permutation of tests imaginable, or did I???

Upon further inspection, I noticed that my AngularJS front end was making two identical calls to my API. This simultaneous connection request was enough to throw the error in the Node/ExpressJS backend.

tl:dr; – Check to be sure your AngularJS / Front End isn’t making simultaneous calls incorrectly to your API/Backend.