# Unit testing, Jasmine, PhantomJS

> Date 07/10/2014

[Second assignment is given.](https://paazmaya.gitbook.io/modern-web-tools-with-node-js/assignments/2-module)

## Unit testing in general

Unit testing, as the name suggests, is a way of testing units or portions of code.

## Popular unit testing frameworks

* [Jasmine](http://jasmine.github.io/)
* [Mocha](http://visionmedia.github.io/mocha/)
* [Qunit](http://qunitjs.com/)
* [nodeunit](https://github.com/caolan/nodeunit)

## PhantomJS, a headless WebKit browser

In an environment where there is no availability of screens, such as a server, continuous integration server specifically, is a need for tools which do not require the screen. One such tool specifically made for browser based testing, is [PhantomJS](http://phantomjs.org/).

However the latest release of PhantomJS, `v1.9.8` from October 2014, is based on a [WebKit](http://www.webkit.org/) from 2011. The next major release (`v2.0.0`) should be out soon and it will be based on a much newer [WebKit](http://www.webkit.org/), via [Qt](http://qt-project.org/) `v5.3` which is used underneath.

## Tasks for the day

1. Add unit tests to your `hello-node-js` repository by using `nodeunit`
   * Unit test spec files are placed in a directory called `tests`
   * Each unit test file named as its targeting source file and `_spec.js` suffix
2. Add a task runner task for running the unit tests
   * Make sure that tests can be run after a fresh clone of the repository,

     followed by `npm i` and `[task runner] test`, for example `grunt test`

## Links related to the lecture subject

* [Testing with Jasmine](http://blog.codeship.io/2013/07/30/testing-tuesday-16-javascript-testing-with-jasmine.html)
* [PhantomJS quick how to](http://www.sitepoint.com/headless-webkit-and-phantomjs/)
* [Video: PhantomJS and Jasmine how to](https://www.youtube.com/watch?v=p5w6oNFT4ks#t=1550)
* [Testing Private Functions in JavaScript Modules](http://engineering.clever.com/2014/07/29/testing-private-functions-in-javascript-modules/)

## Examples for the tasks

### 1. Unit tests with nodeunit

Install dependencies first:

```bash
npm i nodeunit --save-dev
```

Create directory for tests and initial empty test file:

```bash
mkdir tests
touch tests/last-mod_spec.js
```

The test can be written as the following JavaScript, assuming that the `LICENSE` file exists in the repository and its modification date is in October 2014.

```javascript
// last-mod_spec.js

var lastMod = require('../last-mod');

exports.lastMod = function(test){
  test.expect(4);

    // Non existing file
    var non = lastMod('not-to-be-found.js');
    test.strictEqual(non, false, 'False returned when file not existing');

    // Existing file
    var yes = lastMod('LICENSE'); // Date object
    test.equal(yes instanceof Date, true, 'Date object returned when file exists');

    // Correct year and month
    test.equal(yes.getFullYear(), 2014, 'Year is matching');
    test.equal(yes.getMonth(), 9, 'Month is October');

  test.done();
};
```

Run the tests with:

```bash
node_modules/.bin/nodeunit last-mod_spec.js --reporter verbose
```

### 2. Task runner for the unit tests

```bash
npm i grunt-contrib-nodeunit --save-dev
```