Unit testing, Jasmine, PhantomJS

Date 07/10/2014

Second assignment is given.

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

• Mocha

• Qunit

• 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.

However the latest release of PhantomJS, v1.9.8 from October 2014, is based on a WebKit from 2011. The next major release (v2.0.0) should be out soon and it will be based on a much newer WebKit, via Qt 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

• PhantomJS quick how to

• Video: PhantomJS and Jasmine how to

• Testing Private Functions in JavaScript Modules

Examples for the tasks

1. Unit tests with nodeunit

Install dependencies first:

npm i nodeunit --save-dev

Create directory for tests and initial empty test file:

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.

// 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:

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

2. Task runner for the unit tests

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