How to write unit tests in JavaScript for a Windows Store Application

Did you ever tried to write a Windows Store Application for Windows 8 in JavaScript? If yes than I hope that you started working on unit tests also. If no, than in this post we discover how we can write unit test for JavaScript and how we can integrate them in Test Explorer.
First of all why we need to write unit test for JavaScript? Because is like any other programming language that we used until now. When we write code in any language we need to test it. The framework and steps that are describe in this post can be used to write unit tests for JavaScript for a ASP.NET application of for any other project written in JavaScript.
To be able to write test in JavaScript we need to define our test methods that contains a collection of checks. We can write this from scratch or we can use a framework. For this purpose I recommend qunit.  This is a great framework that can be used to write unit tests. We have different version of qunit for Windows Store Application and ASP.NET. After you download this package all that you need to do is to create a project and add this project to it.
After this, all that we need to do is to start writing the unit tests. Basically we need t define a list of function and using methods like equal we can check our unit test assertion. We have a lot of assertion:

• equal – check if two values are equal
• notEqual – check if two values are different
• deepEqual – check if two values are equivalent
• notDeepEqual – check if two values are not equivalent
• strictEqual – check if two values are strict equal (“===”)
• notStricEqual – check if two values are not stric equal (“!==”)
• throws – check if our code throws an exception

The “test” method gives us the ability to define our test function and set the name of our test method. We can define a lot of things but these are the based things that we need. In the following example we define two test methods:

(function () {
    "use strict";
 
    test("my first test", function () {
        var v1 = 5;
        var v2 = 10;
        var sum = v1 + v2;
        equal(15, sum, "Our custom message.");
    });
 
    test("my seccond test", function () {
        var v1 = 5;
        var v2 = 10;
        var sum = v1 - v2;
        equal(15, sum, "Our custom message.");
    });  
})();

In a project for Windows Store when we will run it, qunit will generate a nice UI that will contain the status of each unit test.

As you can see we have a very nice interface that was created where we can read the status of our tests.
Another thing that I like to qunit is the way of output is generated. The output of running the tests is an XML. Over this file a styling is applied for a Windows Store Application. This XML can be used very easily with MSBUILD. There are a lot of scripts that already do this thing.
As you know Visual Studio 2012 contains an improved Test Explorer. Using a plug-in named Chutzpah Test Adapter for the Visual Studio 2012 we can integrate this test in our Test Explorer. In this way we will able to run our C# and JavaScript tests in the same time.

 Using qunit in combination with this plug-in we can create and run unit tests in JavaScript for Windows Store Application without any problem.
Good luck with unit tests.