“brown block lot” by Tim Johnson on Unsplash

Talking to people that are not really into Web Components I found out that they feel like Web Components are not going anywhere. This probably because there was a huge hype around them since, let’s say, a year ago but not that much over the past months.

For those who paid attention, a really important news came out lately. First of all, Microsoft announced they started working on the implementation of Custom Elements and Shadow DOM. This is huge because, since a couple of weeks ago, there were no signs from the Edge Team.
The support in Firefox has finally…


In my previous article, I wrote about how to get started with unit testing in Polymer. The goal was to setup the testing environment and to write your first tests using best practices and taking advantage of the nice tools Polymer offers.

In this article, I’ll cover more advanced topics such as user interaction simulation, automatic testing with Continuous Integration, testing on multiple OS/browsers and more useful tips.

Mock User Interactions

Iron Test Helpers provides a set of methods to simulate mouse or keyboard interaction with an element.

In the example below, you want to be sure that your start button will be…


In the front-end world, testing is a weird topic. Developers know how much testing is important, but lots of them don’t embrace this practice. This is because testing is often perceived as a time consuming and a difficult task.

Sometimes the harder part is just getting started, and this is not only specific to testing. For this reason, in this article we will go through the basics, leaving more advanced topics and some details out. …

Maurizio Mangione

Developer Relations Advocate at DAZN, Google Developers Expert, Microsoft MVP, Milano JS and JS Girls founder. Rock climber, and n00b guitarist.

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