LearnerJS: Back to Basics Presentation

Thanks to everyone who came out for the inaugural meeting of LearnerJS!

Topic

Back to Basics: The importance of testable modular JavaScript components.

Summary

What do jQuery Plugins, Angular Directives, Knockout Components, and Ext JS classes all have in common? Modular Components! In this session we will discuss the importance of modular and reusable JavaScript components, define goals for abstraction and test-ability, and get into some demos showing how to achieve those goals.

Downloads

• Presentation PDF
• Source on GitHub

Enjoy,
Tom

Waiting for Events with Tasks in .NET

Would you like to just await the next time that an event fires? It takes a little setup, but you can!

Migrating your code from using an Event-based Asynchronous Pattern to an Task-based Asynchronous Pattern can be very tricky. You can use the TaskCompletionSource to manage your Task, and then you just need to create the wire up around registering and unregistering your event handler. Unfortunately this process is not nearly as generic as I would like.

Event-based Asynchronous Pattern Tests

Here is a way of waiting for an event to fire by simply sleeping while we wait.

This is a terrible solution because we can not know how long we will have to wait for the event. This means we have to wait for one long time period, or we have to periodically poll to see if the event has fired.

public delegate void SingleParamTestDelegate(int key, string value);

NUnit TestCase, the Data Driven Unit Test

A while back I wrote a blog post about data driven unit testing with xUnit. Back then a reader had to correct me because I did not think that NUnit had support for such things.

NUnit 2.5 added a slew of great features for authoring your own data driven unit tests. Perhaps best of all is the amazing support that ReSharper offers for the NUnit test cases.

You really should be using these amazing features when authoring your unit tests!

• NUnit on NuGet
• TestCaseAttribute
• TestCaseSourceAttribute
• CombinatorialAttribute
• SequentialAttribute

Data Driven NUnit Samples

// Here is a simple example that is the equivalent of an

// inline data attribute from xUnit.

[TestCase(1, 2, 3)]

[TestCase(2, 3, 5)]

public void SimpleSumCase(int a, int b, int expected)

{

    var actual = a + b;

    Assert.AreEqual(expected, actual);

}

How to stream a FileResult from one web server to another with ASP.NET MVC

MVC has a lot of great built in tooling, including the ability to stream very large file results straight from disk without having to load the whole file stream into memory.

What about the scenario where you want to stream a large file from one web server to another?

For example, I have an ASP.NET MVC application that needs to expose a download for a file hosted on another server, but I can not just redirect my users directly to the other URL. For that, we need to create a custom ActionResult type!

WebRequestFileResult

Here is a simple of example of what your controller might look like:

public class FileController : Controller

{

    public ActionResult LocalFile()

    {

        return new FilePathResult(@"c:\files\otherfile.zip", "application/zip");

    }

    public ActionResult RemoteFile()

    {

        return new WebRequestFileResult("http://otherserver/otherfile.zip");

    }

}