Last week, I introduced a data structure kata involving exact square roots. At the time of that writing, I had implemented a RootTerm struct which could represent real and imaginary square roots. Today we’ll pick up where we left off…
Data structure kata: exact square roots
Many programming courses introduce the concept of data structures with complex numbers as a motivating
Microbenchmarks with BenchmarkDotNet
They say that the fastest prime number algorithm for small inputs (up to 216) is a lookup table. But this got me thinking — would it be faster to use HashSet.Contains or a List.BinarySearch? The answer to this type of…
Edge cases: overflow
Consider this (rather suboptimal) prime factorization algorithm: You can run it like so and see that it returns the proper factorization for a variety of Int32 values: In fact, it works properly for any possible Int32 — except one very…
The binary coverage hypothesis
Everyone loves to hate code coverage. But I have started to notice one interesting consequence of using coverage metrics that I refer to as the binary coverage hypothesis: A class should either have full unit test coverage or none at…
Interface anti-patterns: overload overload
Continuing on the theme of interface anti-patterns, let’s talk about overloaded methods. Specifically, let’s talk about overloaded method overload. You’ve probably seen it before. You need to implement an interface and find that there are multiple overloads of each method.…
Interface initialization anti-patterns
It’s a pain that you cannot define constructors for interfaces, isn’t it? To be honest, I’m not so sure… The perceived need for a constructor — typically realized as an Init()-style method — is often a sign of a design…
Nothing beats the real thing
One common pitfall when operating in a mock-heavy TDD context is the tautological test. This is especially true for code which involves awkward dependencies. “I want to avoid talking to the real [database|API endpoint|etc.] here in this class,” you say.…
Living in the test zone
I have previously written that, when given the option of many similar implementation strategies, you should prefer the one which is easiest to test. There is a simple corollary to this proposition: whenever possible, grow your codebase in areas covered…
Take it to the limit: generic type parameters
What is the highest number of generic type parameters can you have on a single type in C#? I know from experience that the answer is at least 130. (Don’t ask.) But is there an upper bound? According to Stack…