Testing in Elixir with Multiple Environments

About a year ago, I was learning how to properly unit test Phoenix applications using the Mox library. The strategy I adopted for my side projects involves adding “module dependencies” to any module I want to unit test, and then using Mox to configure those dependencies during the tests. While that approach is great for […]

Folding Away Mutations in F#

I’ve been working in F# lately, and one of its smaller features has had a big impact on my programming style: Variables are immutable by default. If you want to change something, you have to declare it mutable. Sometimes, this is what I naturally reach for, and the language rubs my nose in it. Here’s […]

Unit Testing Phoenix Controllers with Mox

As the ecosystem for Elixir matures more and more, there are some libraries that seem particularly promising to me. One of them is Mox, a simple but powerful library for implementing mocks for predefined behaviours (note the British spelling!).

An Introduction to Property-Based Testing with JavaScript

Property-based testing is a powerful technique that’s been widely and successfully applied to functional-style codebases for a long time. As functional programming continues to get more and more popular among JavaScript developers, the value of this style of testing is becoming more obvious to a wider audience.

A Simpler Case for Functional Programming & “Elegant” Code

A lot has been written about the benefits of functional programming, but little of it is accessible to a newcomer. Some of the benefits are easy to understand from an inexperienced perspective (e.g. “it makes concurrency easier”), but others are pretty nebulous. Chief amongst the inscrutable properties of functional programming is its “elegance.” It isn’t […]

Pure Computed Properties in Ember

Ember.js has a great way of managing state on objects: computed properties. A computed property is basically a cached function call. If Ember idioms are properly followed, computed properties are pure functions.

Using Decorators to Declaratively Extend Functions

The decorator pattern gained fame in the object-oriented world after being featured in the classic 1994 Gang of Four book, Design Patterns. Since then, it’s been used extensively in traditional object-oriented programming as an alternative to inheritance. What’s really going on behind the scenes though, is composition, which means decorators are also great for cleaning […]

Building Better Board Games with Clojure and Gorilla REPL

A while back, my six-year-old daughter and I were on one of our regular daddy-daughter date nights when we decided to create a board game. We sat at a restaurant table with paper, crayons, and a small collection of Dungeons and Dragons trinkets. To my surprise, we built a fun little game that my daughter […]

4 Tips for Thinking Functionally

I’ve written before about why I prefer a functional programming paradigm to an object-oriented one, but it’s taken a long time to get there. I dabbled on and off for half a decade before the core ideas behind Clojure and Haskell really sank in and I could write code in my head without having to […]

TDD in a REPL

REPLs (Read-Eval-Print-Loops) are often billed as a great place to experiment and learn a language or a framework. They provide a very tight feedback loop. However, it can be difficult or time-consuming to extract the knowledge gained from a REPL and include it in your source code. I’ve hit the up arrow many times in […]

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Functional Programming