OOP Fundamentals: Quick and Dirty Guide to Testing

There are entire books written on testing. And it surely feels more an art than a science. My approach is similar to Kent Beck’s:

I get paid for code that works, not for tests, so my philosophy is to test as little as possible to reach a given level of confidence (I suspect this level of confidence is high compared to industry standards, but that could just be hubris). If I don’t typically make a kind of mistake (like setting the wrong variables in a constructor), I don’t test for it. I do tend to make sense of test errors, so I’m extra careful when I have logic with complicated conditionals. When coding on a team, I modify my strategy to carefully test code that we, collectively, tend to get wrong.


He goes on to add that different people will have different strategies and, at the end of the day, you just have to do what works best for you and your team. Extremely practical, and the approach I personally follow.

This won’t be a detailed post on every possible topic on tests and testing in Object-oriented Programming (OOP). There are many books about that already. Instead, this article will cover the basics of testing, so you understand how and why we test, and you can adapt it to your own needs.

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OOP Fundamentals: The Decorator Pattern

The decorator pattern is one of my favorite patterns. It is simple, extensible and powerful. It feels like it follows the essence of object oriented programming beautifully. Sadly though, it is also easy to be misused or misunderstood. So, in this post I will show you the essence of the decorator pattern, illustrated with a few examples.

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OOP Fundamentals: The Dependency Inversion Principle

The dependency inversion principle is one of the cornerstones of object-oriented programming. Without it, there is no object-oriented design. It’s that important.

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Integrating your dev workflow with WSL

Windows Subsystem for Linux, or WSL for short, is a quite impressive piece of technology, and one of the best moves Microsoft could have made to attract developers. Particularly web developers.

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Composition over Inheritance, with JavaScript examples

If you are into object-oriented programming, you most likely have heard about composition over inheritance. The concept itself is simple: Whenever possible, prefer to compose objects rather than introducing inheritance.

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Common Code Smells in OOP

Over years of reviewing Ruby code, the same things tend to come up over and over. In this post, I’d like to address some of the most common code smells I find when reviewing OOP code (and Ruby code in particular).

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Modularizing The JavaScript You Already Have

Over time, without structure, things fall apart. So give them structure, a few conventions, and start to make them more maintainable. Let me say more, at least in the context of JavaScript in your applications (or did you think I was talking about gardens or buildings or such? lol.)
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A Ruby-ish Xmas

Ruby-ish, rubbish… Get it? Anyways, not like Ruby-ish means bad! Quite the opposite!

It’s the day after Xmas and because Ruby is awesome and delivered 2.6.0, we’ll get to play with some of our new Xmas gifts: Kernel#then, Proc#>> and Proc#<<.

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ePubber – generating ePub files with Ruby

ePub is a digital book format which is pretty common nowadays. It’s supported natively by Windows and Android and it’s one of the official formats for digital books in the Apple Books store.

In this post I’ll talk about generating ePub files with Ruby and how to painlessly integrate this feature to your application. I’ll be using a Ruby gem I created called ePubber, which I created to help manage ePub content.

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Writing a Markdown Compiler – Part 3

Have you ever wanted to make your own programming language? Maybe a template engine? A JSON parser? If you have ever built any of those, you might have noticed it’s not exactly easy to get started. We’d like to help with that.

Welcome to Part 3, the final in this series on Writing a Markdown Compiler!
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Writing a Markdown Compiler – Part 2

Hello, and welcome to the second part of the Writing a Markdown Compiler series! In case you’ve need it, here is Part 1, Intro/Tokenizer and Part 3, Code Generation.

In this part we’ll talk about the second step in compiling: Parsing – also known as Syntactic Analysis. This part has a bit more theory, so it might take some time to digest. Sip some coffee, relax, take yout time, and as long as you don’t rush it you’ll find it’s not hard at all. 🙂

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Writing a Markdown Compiler – Part 1

Have you ever wanted to make your own programming language? Maybe a template engine? A JSON parser? If you have ever built any of those, you might have noticed it’s not exactly easy to get started. There are a lot of concepts to digest before you get going. That’s why lots of devs just give up. We’d like to help with that.

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Writing DSLs: The joy of human consumable APIs

A well-designed Domain Specific Language (DSL) can help you be more productive as a developer, thus making you, your team and your clients happier. In this post, I’ll guide you through the design and creation of a simple DSL to create EPUB files. We’ll start with a regular API and refactoring until we get to a DSL solution.

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Avoid nil-checks. Code confidently. Be happy.

This post is about pretty code (with examples in Ruby), plus how to get nil out of the way and be more confident.

Does this code look familiar?

user && user.ask_for_email

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What is Dependency Injection

If you are a developer, chances are very good that you know what Object-Oriented (OO) code is. You might have also heard about OO Design Patterns, things like single responsibilities, decoupled code, and my subject here: Dependency Injection (DI).

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