Astute readers may have noticed in my previous post about the four fours that I neglected to include exponents in the set of supported mathematical operations. Well, that is fixed now. Perhaps these imagined readers also noticed that my recursive…
Four fours
Back in elementary school, I became aware of the four fours puzzle. It is a seemingly simple mathematical exercise where you must generate all the integers from 1 to 100 using arithmetic expressions and the digit 4 exactly four times.…
Back to (GW-)basics
My foray into programming began with GW-BASIC on a Tandy 1000, an 8-bit IBM PC clone. In those days, one had only a few avenues of learning for coding knowledge: physical books and more experienced friends (who had probably read…
Async holes: StringContent
In a previous post, I introduced the concept of “async holes” — those unexpected gaps and obstacles when using asynchronous APIs in .NET. This time I will tell the tale of the async hole in StringContent. System.Net.Http.StringContent is the derived…
Async holes: ZipArchive
From time to time, I encounter unexpected gaps in asynchronous object models in .NET. I’ve taken to calling these “async holes” since they usually present an unpleasant obstacle in the clear path I try to follow while executing the TDD…
Bring me the simulator, on the double!
The (oft-misunderstood) dependency inversion principle states that abstractions should not depend on details, and instead details should depend on abstractions. As an example, let us first consider a violation of this guideline: The so-called “abstraction” around configuration ConfigFile is very…
Just for the test of it
Ian Cooper implores you to test behaviors, not implementation details. His video “TDD, where did it all go wrong” expands on these points a bit. The summary is that a bunch of really thorough tests with explicit inner knowledge will…
The testable adapter anti-pattern
Let’s say you’re writing a module to deal with Windows optional features. Following the guidance of the Ports/Adapters/Simulators design approach, you come up with a port IFeatures and an adapter WindowsFeatures. “I must make my adapter testable!” you exclaim, and…
Easier to test => better
Rick Mugridge presented a paper “Test Driven Development and the Scientific Method” at the 2003 Agile Development Conference. There he speaks of theory simplicity and draws a parallel between Occam’s razor and the (positive) pressure of TDD to “choose the…
Code coverage is a legacy metric
In the words of Michael Feathers, legacy code is code without tests. My corollary to this is that code coverage is a legacy metric — best applied to these very same legacy systems with poor, inconsistent, or absent testing practices.…