In a previous post “Fluent async testing,” I introduced a sample library to beautify unit tests relying on Task-based assertions. Tests for this type of library typically make heavy use of “canned Tasks” to ensure every case is handled correctly.…
Wake up!
In Effective Unit Testing: A guide for Java developers, author Lasse Koskela writes about the scourge of the sleeping snail — slow tests littered with calls to Thread.sleep. His suggested alternative is perfectly sound and practical: turn nondeterministic waiting into…
Gratuitous complications: unit test fault injection
Sometimes things don’t need to be complicated. I would go so far to say most of the time things don’t need to be complicated. In the words of Uncle Bob Martin, “it is the software engineer’s job to make tough…
Fluent async testing
Cellfish writes: When .net 4.5 was first in public beta most test frameworks had a bug making it impossible to write async test methods. I wish they had never fixed that because I don’t think those help you write good…
The [a]waiting is the hardest part (in 3.5)
In the previous post I showed how to simulate async/await in .NET 4.0. This works great for Task-based async, but what about those who still use stone tools and .NET 3.5? Well, they can share in the fun, too! I…
Just can’t [a]wait (in 4.0)
Writing managed asynchronous code has been possible since the advent of IAsyncResult in .NET 1.0. However, it has not been easy until async/await in .NET 4.5. Unfortunately, there are situations where you really need to implement asynchrony but are stuck…
If at first you don’t succeed
Retries are a fact of life in testing. That file you are trying to read might be temporarily locked. The network connection could momentarily break. You may need to keep pinging a server for status until it returns the result…
Porting InputQueue to C++
In the previous post, I gave a brief intro to the PPL and the basic constructs for writing async C++ code. In this post, I will discuss the highlights of how I ported the InputQueue sample to C++ using the…
InputQueue, the non-BlockingCollection
The .NET 4.0+ solution to the producer-consumer problem is BlockingCollection. A sample app with a single producer and consumer using an ordered queue of integers would look something like this: This is simple enough, but the problem is that DequeueLoop.…
Better tracing with EventSource
Starting in .NET 4.5, managed code developers finally have a simple way to interact with ETW — System.Diagnostics.Tracing.EventSource. For a quick introduction, check out Vance Morrison’s inaugural blog post on EventSource and the also very helpful feature specification. While EventSource…