Use docker for Linux

Reading Time: 1 minute


In this technical post I will explain how I resolved one of my previous issues, running chrome browser in headless in docker.

It seems that if you want to run various docker machines without strange issues, you have to install it on some of supported Linux platforms. For now, Mac and Windows platform are using VirtualBox images that can cause you a lot of headache.

You can go in two directions, create generic docker machine from your Mac (or Windows) on Linux. Or install docker-compose on Linux and do everything from that Linux shell.

I recommend later approach, and here is why.

Create generic docker machine option

You need to prepare Linux user on host machine with following configuration:

  1. user has to be sudoer with no password option
  2. ssh with no password authentication
  3. ssh with public key
  4. port 2376 and 22 opened on firewall

How did I found out those requirements that are not documented? Use docker-machine –debug option.

Why I do not recommend that approach? Because you will be able to communicate with that docker machine only from machine that created it. There are number of explanations how to connect to same docker-machine from two different computers, but none of those approaches worked for me.

Create containers from Linux terminal

I recommend that approach because you will be able to ssh to docker host machine from different computers using ssh.

And remember about my problem  running chrome in headless mode in docker container in VirtualBox? On docker installed on Linux they are not present!

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

Zagreb STC #25 – The art of taking notes

Reading Time: 1 minute


It’s time for Zagreb STC #25 and this time we will have dedicated workshop about taking notes.

Where: Tentamen. d.o.o., Hruševečka 3, 10110 Zagreb, ground floor.

When: Tuesday, June 7th, 2016, from 18.00 – 22.00

We often hear that the most valuable craft of software tester is test automation. In order to prove them wrong, we will make a workshop on taking notes. We will watch 45 minutes of popular detective series and we will make our notes in order to find out who is the killer before show reveals it. We will stop on every 5 minutes for 2 minutes to reconcile our notes.

Material: please bring a notebook and pens in three different colours by your choice.

Reading material: How to take better notes.

After official part, we will continue our discussion over pizza and selection of craft beers.  Sponsor of workshop is Tentamen.



Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

Happy vs. Alternative path

Reading Time: 1 minute


I often hear from developers their definition of done: “Feature is implemented and I have done unit testing that covers happy path”. In this post I will try to elaborate what is on the other side of happy path.

So why they only test for happy path? Because in order to test “alternative paths” you need to have software testing knowledge background. Something like BBST series: Foundations, Bug Advocacy and Test Design. Because testing alternative paths is not SO EASY (like happy path).

And often, alternative path testing is synonym for ALL OTHER TESTING. Like scenario testing, domain testing, risk analysis, taking out requirements from other people’s minds (not literally), non functional testing, …

Which is wrong. For example, functional testing is usually a synonym for feature testing. You test one feature independently from other features. And very often testing stops at that point.

But your product is a sum of all features, your users will use several features in combination just to do one task with your product. And here scenario testing comes into play. And this is heavy lifting, to come up with scenarios that user will possibly trigger. Requirements can only capture just few of those scenarios, which are excellent starting point for software tester to come up with more real scenarios. And that is just scenario testing.

So stop the madness with abandoning your QA team. For those “alternative paths” you do not need developers that know how to code. You need software testers.

And QA is not Quality Assurance, it is Quality Assistance.


Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

Testing with different web page resolutions

Reading Time: 1 minute


This post is about a bug that I missed. I will explain why I missed it and how I created testing strategy in order to prevent missing such bugs in the future.


The bug was manifested in different web page resolution that was used by customer and I did not perform my testing using that resolution.

Issue was in modal window that was not scrollable on resolutions lower than tested resolution. I missed it because varying browser resolutions was not part of my test strategy. (I wrote about it here and did not use it, shame on me!)

So I added to my test strategy browser resolution variable. We also got from customer input data about resolution corner cases, better known as design breakpoints. Basically resolution that we need to cover. Interesting thing was that those breakpoints were not some known resolutions (e.g. iPhone at 320px and 480px), but were all for desktop resolutions.

In order to test those breakpoints (metric are px, which stands for pixels) and different browser resolutions, I needed some tools. Interesting fact was that I had them installed in my browser for some time. Both are chrome extensions:

Resolution test enables you to precisely resize browser resolution. You can define your own resolutions.


Page Ruler helps you to precisely measure web page elements with and height in pixels.


With those two tools I was able to semi automatically test modal window height and width on different page resolutions.


Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

Searching for a pattern

Reading Time: 1 minute


In this post I will talk about important software tester skill, searching for patterns.

Game of Set is popular game at software testers meetups and conferences because it helps testers to train searching for patterns. Why is this important software tester skill?

Because it could help tester in finding possible issues in product under test.

I tested search feature. Simple input box that searched for company employees. It was implemented in Javascript.

I started with simple pattern, enter one letter. Result consisted with employees which name contained at least one search letter. But some employees were missing in search results.

Example test data set:

Karlo Smid

Big King Karlo

Smid, Karlo

Gloria, K. 

Search for: K

Result set:

Karlo Smid

Big King Karlo

Stop here. Can you identify the error pattern?

I used different letter and confirmed error pattern. Result set was missing employees that had searched letter in their name after the comma.

Interesting pattern.


Go to online game of set and start practicing your pattern searching skill!

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather