Tag Archives: knockout

Integrating Javascript Unit Tests with Visual Studio – Testing your Javascript

First, let’s pause…the point of this post series is how to integrate your javascript unit tests with Visual Studio, not to teach you how to use the frameworks I’m discussing. The rest of this post is going to assume you’re familiar with KnockoutJS and Qunit.

Knockout is a framework in javascript that let’s you create javascript viewmodels for your html page. When done correctly, your view model simply maintains it’s own state and is blissfully unaware of the existence of any HTML elements. This is one of the death knells of your javascript unit tests. When your javascript knows about html structure and elements it forces you to mock your view out when unit testing otherwise you can’t properly test it. Knockout let’s you write clean testable javascript and move the glue between your code and the HTML DOM into a declaritive data binding syntax in the HTML. Again, not here to teach you Knockout, much better places to learn that, like so:

http://learn.knockoutjs.com/

Likewise, Qunit is the javascript unit testing framework used by jQuery. It seems like the modern internet wouldn’t exist without jQuery, so we might as well run with that, even though there a number of javascript unit test frameworks out there.

http://docs.jquery.com/QUnit

To integrate our tests we’re going to need some code to tests and tests to test it first, so let’s start there. I’ve stolen the following view model from the knockout tutorial site:

function AppViewModel() {
    this.firstName = ko.observable("Nick");
    this.lastName = ko.observable("Olson");

    this.fullName = ko.computed(function() {
        return this.firstName() + " " + this.lastName();
    }, this);

    this.capitalizeLastName = function() {
        var currentVal = this.lastName();        // Read the current value
        this.lastName(currentVal.toUpperCase()); // Write back a modified value
    };
}

What should we unit test? Well, we’ve got the fullName property which has some logic, and the function to capitalize the last name, so let’s start there.

$(function () {
        module("My First Tests");

        test("FullNameTest", function () {
            var model = new AppViewModel();
            equal("Nick Olson",model.fullName(), "full name built properly");
        });

        test("capitalizeTest", function()
        {
            var model = new AppViewModel();
            model.capitalizeLastName();
            equal("OLSON",model.lastName(), "capitalize works");
        });
    });

To see it all in action, check it out here:
http://jsfiddle.net/x6be5/2/

 

 

Integrating Javascript Unit Tests with Visual Studio – Intro

I’ve been working on a project over the last few months that quickly evolved from a Silverlight project to an ASP .NET MVC3. If you’re shifting from Silverlight to MVC and want to maintain that rich client interaction, it means that you’re probably going to be writing a lot of javascript code.

In fact, we quickly realized that we were really writing a javascript client application with a .NET backend. This can be a scary proposition when it’s your first real foray into heavy javascript development. It seems like the first thing to go is the logical structuring and thought that you’d put into your code if this were a strongly typed language. Something about that <script/> tag that just makes you want use it and throw thousands of lines of javascript at it.

As a result, next to go are your unit tests if you had any to begin with.  I will confess, I’ve never been a huge unit tester.  But once you start working with dynamic languages and your warm fuzzy “Build Succeeded” blanket is taken away, I’ll reach for whatever comfort I can get.

The goal of this series of posts is to walkthrough what I did to unit test my javascript and get those test results into Visual Studio’s test output.  Although I may touch briefly on how to use the frameworks I’m talking about, the focus will be gluing them together.

That said here’s what we’ll be working with:

  • MVC3 w/ Razor
  • Qunit
  • KnockoutJS
  • XML/XSLT
  • Watin
  • C# Data-driven unit tests
Some of these ideas were cobbled, stolen and enhanced from other places, so if you can’t wait here is where I started off: