Recently I have been coding a lot in Dart, mostly Flutter apps. While doing integration testing of some code I put together a mock Web Server based in the one for Java created by Square.

Understanding Integration Tests

Integration tests are required when we want to check that our code is interacting correctly with other systems. Most of the time this means sending proper HTTP requests and handling the responses correctly.

The best way of doing these type of tests is by calling a server that is scripted so that the interaction with it is deterministic. …

With the release of Kotlin 1.1.0, I decided to give a try to Kotlin’s Coroutines on Android. I had some ideas about what I wanted to build as a Proof of Concept, trying to showcase what I think are the most obvious advantages of using coroutines.

Update March 1st: Updated and tested with Kotlin 1.1.0 and coroutines-core 0.12

Update Feb 24th: Tested with Kotlin RC 1.1 and updated the repo. Check the announcement here.


  • Call a service using okHttp and parse/display the information without using a callback
  • Handle the exception if the device is not connected to the internet (IOException)…

Avian is a lightweight JVM that will allow you to create self-contained apps. That means that you can ship your app without forcing your users to install any JRE. In here, we will follow simple steps that are going to allow us to create a stand-alone hello-world app using Kotlin.

Why Kotlin?

Kotlin is a great language with a lot of potential. I am not going to go through all the advantages of it since a lot of people before me has done it already. So we will leave it at that, great language with a lot of potential. …

Android Developer, Kotlin and Flutter evangelist, macastiblancot[at]gmail,

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