In the beginning of my career, I discovered that having automated tests is invaluable when making changes to any non-trivial software system. Or, put differently, I realized that changing a non-trivial software system without having the support of a suite of automated tests is both risky and time consuming.

A while back, I got fed up with writing code. Not writing code in general, mind you, but I did face a situation where I needed to write a lot of boilerplate code, and having to write such code is a certain way of losing interest in software development. Not …

I recently came across a thread discussing Test-Driven Development (TDD) on one of the major social networks. The discussion revolved around when to use TDD and when it can be skipped. As a consistent TDD practitioner, I find these discussions interesting, especially when it comes to understanding the perspectives of …

For this year’s Advent of Code, I use the programming language Nim. I wrote a little bit about Advent of Code yesterday.

For today’s puzzle, I got stuck on something that normally is so trivial that you don’t think twice about it—accessing a variable in the …

The time has come for another December with the alarm clock set earlier than usual! The yearly Advent of Code challenge opened its gates to the first puzzle at 00:00 Eastern Time, meaning 06:00 in Sweden.

This is my 6th year, and I’m looking forward to a …

Co-authors: Andreas Cederström and Sebastian Porling.

Cypress has recently released support for component testing in their 10.0 release. You read the announcement here. We decided to take a quick look and try it out, to gather some first impressions and see how it can fit into our development workflow …

In today’s post, I’ll talk about array covariance in C#, how it hid a bug in code that was covered by a passing unit test (*gasp*), and some ideas for how to avoid such bugs.

What is covariance?

In computer science, variance has to do with how complex …

Can you combine Test-Driven Development (TDD) with prototyping? How can you write tests for functionality that is largely unknown? Where do you even start if you’re on unfamiliar ground and you need to explore to learn about possibilities and constraints? How can you write tests when you don’t …

I previously wrote about how to get a useful diff for binary Excel files that reside in a Git repository.

This post adds some details that are big enough to deserve a separate post. They are:

• User-level configuration of Excel diffing.
• How to get an Excel diff from git show …

The JSObject interface in Nashorn makes it possible to expose an object to script code and control in detail how it appears and behaves. The purpose of this article is to explain when the different JSObject methods are called during script execution and in some cases how they should be implemented.