Wolk Software Engineering

by Wolk Software Limited

A group of young and ambitious people dedicated to creating cutting-edge applications in combination with beautiful and functional design.

Read this first

The most important practical lesson that JavaScript has taught us

The incredible rise in popularity that JavaScript has experienced over the last decade has been spectacular. According to the yearly developer survey by StackOverflow [1], JavaScript is today the most popular programming language in the world:

JavaScript also leads the ranks in other studies and surveys like the quarterly Programming Language Rankings by Redmonk [2] or the 2018 Developer Skills Report by HackerRank [3]:

The success of JavaScript has been so spectacular that we even have a “law” about it [4]:

Any application that can be written in JavaScript, will eventually be written in JavaScript.

However, the success of JavaScript has not been free of detractors. JavaScript has been the source of inspiration for some well-known jokes:

JavaScript has been the focus of a lot of negative criticism, It has even been described by some as “a phenomenon of mass psychosis” [5]:

Continue reading →

Learn how to contribute to the TypeScript compiler on GitHub through a real-world example

A few days ago I managed to send my first PR to the TypeScript project on GitHub. This is something that I’ve been trying to do for a very long time but unfortunately, it felt way too complicated for me.

I decided to write this post because I’m 100% sure that there are a lot of people out there feeling just like me. I’m going to try to describe how I personally found a way to contribute. My goal is to hopefully help others to contribute as well.

Please note that I’m not an expert in the TypeScript compiler internals. Please correct me using the comments below if I say is wrong.


I’m going to assume a few things in this article:

  • You understand Git and have already installed it on your machine.
  • You understand TypeScript and have been using it for a while.
  • You understand the GitHub Flow and you already have a GitHub account.

 A real-world example

I’m going to use a

Continue reading →

Dependency injection in TypeScript applications powered by InversifyJS


InversifyJS is a lightweight inversion of control (IoC) container for TypeScript and JavaScript apps. InversifyJS uses annotations to identify and inject its dependencies.

The InversifyJS API had been influenced by Ninject and Angular and encourages the usage of the best OOP and IoC practices.

InversifyJS has been developed with 4 main goals:

  1. Allow JavaScript developers to write code that adheres to the SOLID principles.

  2. Facilitate and encourage the adherence to the best OOP and IoC practices.

  3. Add as little runtime overhead as possible.

  4. Provide a state of the art development experience.

 Motivation and background

Now that ECMAScript 2015 version of JavaScript supports classes and that TypeScript brings static types to JavaScript application, the SOLID principles have become more relevant than ever before in the development of JavaScript applications.

InversifyJS was

Continue reading →

How to create your own TypeScript type definition files (.d.ts) and contribute to DefinitelyTyped on GitHub

 Learn how to create your own type definition files and how to contribute to the TypeScript community at DefinitelyTyped

 Helping your community is AWESOME

It is Saturday evening and it’s raining a lot in Ireland. So I decided to spend some time on Twitter looking for interesting TypeScript news. Over the last year I’ve been using the @DubTypeScript account to share TypeScript news. This is the official account of the Dublin TypeScript Meetup which is based in Dublin (Ireland) and is organized by myself.

I was searching for interesting tweets when I found the following one:

Screen Shot 2016-10-15 at 19.19.45.png

When I saw this tweet I was automatically thrilled because it is AWESOME when you find an opportunity to help the community like this.

I really think it is sad that only a small percentage of all the software engineers out there contribute to open source. Contributing to open source is not easy for newcomers

Continue reading →

The rise of functional programming & the decline of Angular 2.0

 Learn why we believe that the rise of functional programming (FP) will prevent Angular 2.0 from being as successful as its predecessor.


Angular 2.0 RC.5 was just released last week and is now really close the long-awaited 2.0 release.

After the success of Angular 1.0, it is normal to expect a huge success for Angular 2.0. However, we feel that there are reasons to believe that Angular 2.0 will not be as successful as its predecessor.

We believe this because we have been observing the front-end development trends and we have noticed a significant shift within the JavaScript community.

Let’s learn what this “shift” is about.

Note: JavaScript transpilers like Babel, TypeScript or Elm are out of the scope of this article. But you should really try Elm.

 A little bit of history

JavaScript is a multi-paradigm programming language. On its early days, it was mostly used as a scripting

Continue reading →

Dependency injection in React powered by InversifyJS

 Most of the solutions for dependency injection (DI) in React components are based on context. The famous connect function and the Provider there use the context. However, the React development team recommends avoiding the usage of the context. In this article we will learn how we can use InversifyJS as a context-free solution for DI in React applications.


A few weeks ago, an user in Twitter asked Michel Weststrate (the author of MobX) the following:


His answer was the following:


Later, the popular repository react-in-patterns documented the most common dependency injection patterns in React applications but some developers mentioned InversifyJS once more:


I was surprised after reading the following in react-in-patterns:

Most of the solutions for dependency injection in React components are based on context. I think that it’s good to know what happens under the

Continue reading →

Announcing InversifyJS 2.0.0 Release Candidate ?

Learn what’s new in InversifyJS 2.0.0 and what can you expect to see in the future of this powerful lightweight IoC container for JavaScript and Node.js apps powered by TypeScript


As many of the readers of this blog already know, over the past year and a half we have been working on InversifyJS.

InversifyJS is a powerful lightweight IoC container for JavaScript and Node.js written in TypeScript.

Last march we announced that we were working on InversifyJS 2.0. Today we are happy to announce that InversifyJS 2.0 release candidate is available on npm.

In this post we are going to learn about the following:

  • Setting up InversifyJS 2.0 with TypeScript
  • The InversifyJS 2.0 API
  • The InversifyJS 2.0 features
  • The InversifyJS ecosystem
  • The InversifyJS community

Let’s get started!

 Setting up InversifyJS 2.0 with TypeScript

$ npm install inversify@2.0.0-beta.5 reflect-metadata --save
$ npm

Continue reading →

About object-oriented design and the “class” & “extends” keywords in TypeScript / ES6

A few weeks ago I found an interesting article titled In Defense of JavaScript Classes. The article exposed some concerns about the class keyword in ES6 / TypeScript:

These days it feels like everyone is attacking classes in JavaScript. Developers I respect say ES6 classes are a virus. We’ve compiled long lists on the reasons that ES6 classes are not awesome. Apparently, if we’re still brave enough to try them, we need advice on how to use classes and still sleep at night.

The problems that I see with the class and extends keywords in ES6 / TypeScript are not something new. I believe that these problems are cause by bad object-oriented (OO) design and I’m sure that the source of most of the criticism is coming from programmers with a strong interest in functional programming and I understand their fears. They are afraid of some of the OOP “monsters”:

  • Inheritance
  • Internal classes

Continue reading →

Introducing redux-bootstrap

 Bootstrapping function for Redux applications

We are happy to announce that we just open-sourced a small library for the redux ecosystem called redux-bootstrap.


redux-bootstrap is a bootstrapping function for Redux applications. Redux bootstrap does not generate files for you. It is not a project template or project scaffolding tool and it is not related with Bootstrap (responsive web apps framework).

Redux-bootstrap handles most of the common application initialisation / bootstrapping that takes place every time you create a new Redux project.


When you create a new Redux project you usually need to take care of a few things:

  • Install dependencies.
  • Integrate the React router with Redux.
  • Create a Root reducer.
  • Enable DevTools is environment is development / Disable if environment is production.
  • Integrate Immutable with Redux.
  • Apply middleware.
  • Combine reducers into a

Continue reading →

The current state of dependency inversion in JavaScript

Learn about the past, present and future of dependency inversion in JavaScript

Over the last year and a half, I’ve been reading a lot about dependency inversion and taking a look to the source code of many open-source IoC containers for JavaScript. At the same time I’ve been working on the development of InversifyJS (a powerful IoC container for JavaScript apps powered by TypeScript).

I have spent a lot of time thinking and talking about DI in JavaScript with many developers and I found this topic to be quite controversial. I’m writing this post to share what I’ve learn.

 Debunking the JavaScript IoC container myths

Before I go into details about past, present and future of dependency inversion in JavaScript I will try to debunk what I believe are some myths.

Screen Shot 2016-03-20 at 21.46.05 (2).png

 Myth 1: There is no place for IoC containers in JavaScript

When I have a conversation about decoupling and modularity in

Continue reading →