JavaScript

A Stack data structure in TypeScript

The JavaScript Array has everything to acts as a nice Stack structure, the only thing is missing is a peek() method. In this blog I’ll discuss two ways of implementing a stack based on the array.

Incorporate free ngrok in your Node.js application for local development

I’ve tried to use the ngrok npm package in my application, but as the documentation says: “The ngrok and all tunnels will be killed when node process is done.” I need the process to “survive” my application. Let’s see what we can do about that…

Convert JsFiddle to SVG using Node.js

I love SVG, but sometimes they are hard to create, especially when you need to visualize diagrams. HTML is way easier to program. So why not combine them? Can we use HTML to generate an SVG? And can we use JsFiddle to generate that HTML?

Fizz? Buzz? FizzBuzz? Let’s discuss.

What’s the buzz all about? Well, originally it started out as a small children’s game, but now and again I see it being used to detect weak developers in job interviews (I think there are better ways to do this). The assignment has a view nice properties. In this blog I would like to look at some implementations and discuss the pro’s and con’s of each implementation.

Building an updatable Slack message

Slack is fully awesome. At Wehkamp we use it for our internal communication and as a tool for our DevOps. The Slack API allows us to build even more advanced integrations. In this blog I’ll explore how to use the API to create powerful progress indicators by updating a Slack message.

Jump-starting Slack bot projects: bot-zero

To give teams a jump start we’ve created the bot-zero open source project. It solves some setup and development problems. In this blog I’ll show how to get up and running in minutes and I’ll explain some of the choices we’ve made.

Hubot + ES6 + Promises

Lately we’ve been playing around with ChatOps at Wehkamp. We added a Hubot to our Slack channels to automate some operational jobs. It makes work more fun and way easier. As it is hosted in our own infrastructure, it can interact with our micro-services. In this article I explore how to use ES6 and a Promise to implement a call to a simple web-service.

Conditioning Knockout Observables: reject values

Wouldn’t it be nice if we could restrict the value written to a Knockout observable? Some values might mess up your model completely while others just don’t make sense. How would one create a conditioned observable that rejects invalid values? It turns out that conditioning an observable is not so hard.

Support both Node.js and browser JS in one TypeScript file

TypeScript allows for better JavaScript development. JavaScript is getting useful in more domains. But different systems require different ways of handling modules and exposing features. TypeScript solves this by compiling differently when a target is specified.

But what if you need a TypeScript script that supports both vanilla browser JS and Node.js? What if you need to expose 10+ classes?

Convert QUnit test to Mocha / Chai

Recently I’ve been playing around with NPM. I switched my unit tests from QUnit to Mocha. This was not as straight forward as one would hope. In this blog I’ll show some example code. At the end I’ll link to a side by side comparison of the entire test project. Hopefully it helps you to convert your code. I’ll be using the Chai BDD assertion engine.