In the last couple of posts, I've demonstrated how to isolate implementation from WCF contract definition and behavior in a duplex communication scenario. These posts have been rather detailed, so it occurred to me that you might benefit from an overview. The main goal was to ensure testability of...

In my previous post , I explained how to unit test a WCF service with callbacks. Since the scenario involves duplex communication, the service is also a client, and vice versa, so it's only reasonable to look at the 'client' as well, to examine how to best approach unit testing such a beast. Since...

In my previous post , I explained how to implement a WCF service without referencing WCF. In simple cases, it works as described, but you may soon find yourself in a situation where you need to modify the behavior of the service when it's hosted by WCF. Perhaps you need to control the service's ConcurrencyMode...

Some of the new stuff in .NET 3.5 makes it much easier to implement Provider Injection . If you take a close look at the provider definition, you may discover that when used with Provider Injection, only a single method (Create, or something similarly named) is ever used by the consumer. As such, what...

Now that both of my TechEd sessions are over, I've had some request for the sample code that I demonstrated at both sessions. The sample code I used at the interactive talk on TDD is attached to this post. The code I demonstrated at my talk on manual and dynamic mocks is available upon request...

Again this year, I'll be presenting at TechEd Developers in Barcelona next month. This year, I'll be doing both a general session on mocks, as well an interactive session on TDD. You can read more on these sessions by using the conference's Session Search tool and selecting my name (Mark Seemann) in...

Besides logging, one of the most common types of ambient context is the user. Who is the user? Was the user authenticated? What is the user allowed to do? Since being able to answer these questions are such common requirements in software development, the BCL includes the IPrincipal interface that...

In my former post on Ambient Contexts , I described how you can use CallContext or Thread Local Storage (TLS) to store a context that is specific to the current context of a call. As it turns out, ASP.NET uses a threading model that disables this approach , since you are not guaranteed that a single...

These days, I'm becoming increasingly enamored with the idea of implementing cross-cutting concerns using Thread Local Storage (TLS) or the current call context. For the most typical aspects of software, such as security and logging, the .NET framework already takes this approach: Security can...

There are several different ways to implement Dependency Injection (DI), and Martin Fowler describes four of them in his excellent article on IoC/DI . In this article, the first three approaches (Constructor, Property, and Interface Injection) are mainly described as a background for introducing the...

In his article on Inversion of Control and Dependency Injection , Martin Fowler has a quite interesting section towards the end where he talks about how to configure loosely coupled systems. One of his points is that in some cases, it makes more sense to tie it all together using code than by using a...

This is the fourth in a small series of posts about testing against non-determinism. In this installation, I'm going to cover the passage of time. In my former post , I demonstrated how you can use the Provider Injection pattern to decouple your test target from a direct dependency of the current...

This is the third in a small series of posts about testing against non-determinism. In this installation, I'm going to cover how to deal with the current time or date. If you have logic that is dependent of the current time or date, test results will vary according to the time you run your tests....

This is the first in a small series of posts about testing against non-determinism. In this installation, I'm going to cover randomness. When code paths are selected at random, the outcome of a unit test may not be deterministic. Consider this example: public bool DoRandomStuff() { Random r = new...

In his article Inversion of Control Containers and the Dependency Injection pattern , Martin Fowler describes four types of inversion of control: Constructor Injection Property Injection Interface Injection Service Locator Constructor injection and service locator are, in my opinion...

After far too much delay, today I have finally released Service Locator 2 to the web. Since GotDotNet is being phased out, I have moved the project to CodePlex , which means that you should go to Service Locator's new home to download the new release. So, what is it? Service Locator 2 addresses late...

In many scenarios, console applications are very useful, but if you have a console application of intermediate complexity, you should obviously unit test it like all the other code you write - right? If you have a console application as an administration utility for a complex piece of software you are...

In my previous post I demonstrated how to create an application based on the Composite UI Application Block (CAB) while truly separating Views from Controllers by placing them in separate assemblies. My main motivation for separating these application layers is to enable unit testing of the Controller...

The Composite UI Application Block (CAB) is a pretty nice piece of technology that allows you to separate user interface code from user interface process code, following some variant of the Model View Controller (MVC) pattern. The QuickStarts that ship with CAB demonstrate how to use different features...

A new version of the Service Locator Enterprise Application Block is now available. At version 1.1, not much is new: I've added a method which allows a developer to clear all injected services from the InjectionServiceProvider. The idea is that, in unit testing, all tests should be independent, so you...