you can logoff, but you can never leave

A 5 year old girl vs. CoderDojo

Adi @ Hello Ruby

In early December'16 together with my 5 year old daughter we visited an introductory workshop about the Hello Ruby book and another workshop organized by Coder Dojo Bulgaria. Later that month we also visited a Robo League competition in Sofia. The goal was to further Adriana's interest into technical topics and programming in particular and see how she will respond to the topics covered and the workshops and training materials format in general. I have been keeping detailed notes and today I'm publishing some of my observations.

The events that we visited were strictly for small children and there were mentors who worked with the kids. Each mentor, depending on the event works with up to 4 or 5 children. Parents were not allowed to interfere and I have been keeping my distance on purpose, trying to observe and document as much as possible.

Hello Ruby

Hello Ruby is a small book with colorful illustrations about a girl who embarks on adventures in programming. Adriana considers it a fairy tale although the book introduces lots of IT related terms - Ruby and gems, Firefox, Snow Leopard, Django, etc. For a child these don't necessarily mean anything but she was able to recognize my Red Hat fedora which was depicted on one of the pages.

The workshop itself was the introduction of the Bulgarian translation, which I've purchased, and had the kids build a laptop using glue and paper icons. Mentors were explaining to the children what the various icons mean, that viruses are a bad thing for your computer, what a CPU and computer memory are and everything else in between. A month later when Adriana started building a new paper computer on her own (without being provoked by me) she told me that the colored icons were "information" that goes into the computer!

After the story part of the book there are exercises designed to create analytical thinking. We did only a few in the beginning where she had to create a list of action sequence how to make the bed or get dressed up in the morning, etc. At the time Adriana didn't receive the game very well and was having some troubles figuring out the smaller actions that comprise a larger activity. We didn't follow through with the game.

At the second event she was exposed to! At the time we were required to bring a working laptop and a mouse. I had no idea how these were going to be used. It turned out mentors gave each child a training course from according to their age. Adriana started with the Course #1 because she can't read on her own!

At first it seemed to me that Adi was a bit bored and didn't know what to do, staring cluelessly at the screen. Btw this was her first session working with a computer on her own. After a while the mentor came and I guess explained what needs to be done, how the controls work and what the objective of the exercise was. After that I noticed she's working more independently and grew interested in the subject. She had a problem working with the mouse and after 2 days I've nudged her to use the TrackPoint and mouse buttons on a ThinkPad laptop. She uses them with both hands, so am I btw, and is much more adept at controlling the cursor that way. If you are going to teach children how to work effectively with a computer you may as well start with teaching them to work effectively with a track pad!

The courses are comprised of games and puzzles (which she's very good at) asking children to perform a very basic programming concept. For example instruct an angry bird to move left or right by using blocks for each instruction. By the time the workshop was over Adriana had completed 4 levels on her own.

Level 5 introduced a button for step-by-step execution of the program also colloquially known as debugging :). The first few exercises she had no idea what to do with this debugging button. Then the 6th exercise introduced a wrong starting sequence and everything snapped into place.

Level 7 introduced additional instructions. There are move left/right instructions as well as visit a flower and make honey instruction. This level also introduces repeating instructions, for example make honey 2 times. At first that was confusing but then she started to take a notice at the numbers shown on screen and started to figure out how to build the proper sequence of blocks to complete the game. When she made mistakes she used the debugging button to figure out which block was not in place and remove it.

After this level Adi started making more mistakes, but more importantly she also started trying to figure them out on her own. My help was limited to asking questions like "what do you need to do", "where are you at the screen now", "what instructions do you need to execute to get where you want to be".

Level 8 introduces a new type of game, drawing shapes on the screen. The hardest part here is that you need to jump from one node to another sometimes. This is great for improving the child spatial orientation skills.

Level 11 is a reading game in English. You need to instruct a bee to fly across different letters to complete a word shown on the screen. However Adriana can't read much less in English, although she understands and speaks English well for her age. In this case I believe she relied on pattern recognition to complete all exercises in this level. She would look at the target word and then identify the letters on the playing board. Next she would stack instruction blocks to program the movements of the bee towards her goal as in previous exercises.

Level 13 introduces loops. It took Adriana 7 exercises to figure out what a loop is, identify the various elements of it and how to construct it properly. She also said that was amusing to her. Almost immediately she was able to identify the length of the loop by herself and construct loops with only 1 block inside their body. Loops with 2 or more blocks inside their body were a bit harder.

Level 14 introduced nested loops, usually one or more instruction blocks paired with a loop block, nested inside another loop block. For example: repeat 3 times(move left, repeat 2 times(move down)). Again it took her about 6 exercises to figure them out. This is roughly at the middle of the level.

Level 16 was quite hard. It had blocks with parameters where you have to type in some words and animal characters will "speak these words" as if in a comic book. I'm not sure if there was supposed to be a text to speech engine integrated for this level but sounds like a good idea. Anyhow this level was not on-par with her skills.

The course completed with free range drawing using instruction blocks and cycles. The image she drew was actually her name where she had to guess how much scribbles the painter needs to do in one direction, then traverse back and go into another direction. She also had to figure out how big each letter needs to be so that it is possible to actually draw it given the game limitations in motion and directions. This final level required lot of my help.


I have never had any doubts that small children are very clever and capable of understanding enormous amounts of information and new concepts. However I'm amazed by how deep their understanding goes and how fast they are able to apply the new things they learn.

Through games and practical workshops I believe it is very easy to teach children to gain valuable skills for engineering professions. Even if they don't end up in engineering the ability to clearly define goals and instructions, break down complex tasks into small chunks and clearly communicate intentions is a great advantage. So is the ability to analyze the task on your own and use simple building blocks to achieve larger objectives.

I will continue to keep notes on Adi's progress but will very likely write about it less frequently. If you do have small children around you please introduce them to Hello Ruby and and help them learn!

Thanks for reading!

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Circo loco 2017

HackConf 2016

Due to popular demand I'm sharing my plans for the upcoming conference season. Here is a list of events I plan to visit and speak at (hopefully). The list will be updated throughout the year so please subscribe to the comments section to receive a notification when that happens! I'm open to meeting new people so ping me for a beer if you are attending some of these events!

02 February - Hack Belgium Pre-Event Workshops, Brussels

Note: added on Jan 12th

Last year I had an amazing time visiting an Elixir & Erlang workshop so I'm about to repeat the experience. I will be visiting a workshop organized by HackBelgium and keep you posted with the results.

03 February - Git Merge, Brussels

Note: added on Jan 12th

Git Merge is organized by GitHub and will be held in Brussels this year. I will be visiting only the conference track and hopefully giving a lightning talk titled Automatic upstream dependency testing with GitHub API! That and the afterparty of course!

04-05 February - FOSDEM, Brussels

FOSDEM is the largest free and open source gathering in Europe which I have been visiting since 2009 (IIRC). You can checkout some of my reports about FOSDEM 2014, Day 1, FOSDEM 2014, Day 2 and FOSDEM 2016.

I will present my Mutants, tests and zombies talk at the Testing & Automation devroom on Sunday.

UPDATE: Video recording is available here

I will be in Brussels between February 1st and 5th to explore the local start-up scene and get to meet with the Python community so ping me if you are around.

18 March - QA Challenge Accepted 3.0, Sofia

QA: Challenge Accepted is a specialized QA conference in Sofia and most of the sessions are in Bulgarian. I've visited last year and it was great. I even proposed a challenge of my own.

CFP is still open but I have a strong confidence that my talk Testing Red Hat Enterprise Linux the MicroSoft way will be approved. It will describe a large scale experiment with pairwise testing, which btw I learned about at QA: Challenge Accepted 2.0 :).

UPDATE: I will be also on the jury for QA of the year award.

07-08 April - Bulgaria Web Summit, Sofia

I have been a moderator at Bulgaria Web Summit for several years and this year is no exception. This is one of the strongest events held in Sofia and is in English. Last year over 60% of the attendees were from abroad so you are welcome!

I'm not going to speak at this event but will record as much of it as possible. Checkout earlier recordings on my YouTube channel and hurry up because tickets are almost sold out!

10-12 May - Romanian Testing Conference, Cluj-Napoca

RTC'17 is a new event I found in neighboring Romania. The topic this year is Thriving and remaining relevant in Quality Assurance. My talk is titled Quality Assistance in the Brave New World where I'll share some experiences and visions for the QA profession if that gets accepted.

As it turned out I know a few people living in Cluj so I'll be arriving one day earlier on May 9th to meet the locals.

13-14 May - OSCAL, Tirana

Open Source Conference Albania is the largest OSS event in the country. I'm on a row here to explore the IT scene on the Balkans. Due to traveling constraints my availability will be limited to the conference venue only but I've booked a hotel across the street :).

I will be meeting a few friends in Tirana and hear about the progress of an psychological experiment we devised with Jona Azizaj and Suela Palushi.

Talking wise I'm hoping to get the chance of introducing mutation testing and even host a workshop on the topic.

20-21 May - DEVit, Thessaloniki

This is the 3rd edition of DEVit, the 360° web development conference of Northern Greece. I've been a regular visitor since the beginning and this year I've proposed a session on mutation testing. Because the Thessaloniki community seems more interested in Ruby and Rails my goal is to share more examples from my Ruby work and compare how that is different from the Python world. There is once again an opportunity for a workshop.

So far I've been the only Bulgarian to visit DEVit and also locally known as "The guy who Kosta & Kosta met in Sofia"! Checkout my impressions from DEVit'15 and DEVit'16 if you are still wondering whether to attend or not! I strongly recommend it!

01-02 June - Shift Developer Conference, Split

Shift appears to be a very big event in Croatia. My attendance is still unconfirmed due to lots of traveling before that and the general trouble of efficiently traveling on the Balkans. However I have a CFP submitted and waiting for approval. This time it is my Mutation Testing in Patterns, which is a journal of different code patterns found during mutation testing. I have not yet presented it to the public but will blog about it sometime soon so stay tuned.

03-04 June - TuxCon, Plovdiv

TuxCon is held in Plovdiv around the beginning of July. I'm usually presenting some lightning talks there and use the opportunity to meet with friends and peers outside Sofia and catch up with news from the local community. The conference is in Bulgarian with the exception of the occasional foreign speaker. If you understand Bulgarian I recommend the story of Puldin - a Bulgarian computer from the 80s.

17-18 June - How Camp, Varna

How Camp is the little brother of Bulgaria Web Summit and is always held outside of Sofia. This year it will be in Varna, Bulgaria. I will be there of course and depending on the crowd may talk about some software testing patterns.

September or October - SEETEST, The Balkans

South East European Software Testing Conference is, AFAIK, an international event which is hosted in a major city on the Balkans. Last year it was held in Bucharest with previous years held in Sofia.

In my view this is the most formal event, especially related to software testing, I'm about to visit. Nevertheless I like to hear about new ideas and some research in the field of QA so this is a good opportunity. I'm not planning to speak at this event!

21-22 October - HackConf, Sofia

HackConf is one of the largest conferences in Bulgaria, gathering over 1000 people each year. I am strongly affiliated with the people who organize it and even had the opportunity to host the opening session last year. The picture above is from this event.

The audience is still very young and inexperienced but the presenters are above average. Organizers' goal is HackConf to become the strongest technical conference in the country and also serve as a sort of inspiration for young IT professionals.

Each year the conference has a topic and I have no idea what the topic for 2017 will be. In any case I think I will have something interesting to share with the public.

October - IT Weekend, Bulgaria

IT Weekend is organized by Petar Sabev, the same person who's behind QA: Challenge Accepted. It is a non-formal gathering of engineers with the intent to share some news and then discuss and share problems and experiences. Checkout my review of IT Weekend #1 and IT Weekend #3.

The topic revolve around QA, leadership and management but the format is open and the intention is to broaden the topics covered. The event is held outside Sofia at a SPA hotel and makes for a very nice retreat. I don't have a topic but I'm definitely going if time allows. I will probably make something up if we have QA slots available :).

October - Software Freedom Kosova, Prishtina

Software Freedom Kosova is one of the oldest conferences about free and open source software in the region. This is part of my goal to explore the IT communities on the Balkans. Kosovo sounds a bit strange to visit but I did recognize a few names on the speaker list of previous years.

The CFP is not open yet but I'm planning to make a presentation. Also if weather allows I'm planning a road trip on my motorbike :).

16-17 November - ISTA Con, Sofia

Innovations in Software Technologies and Automation started as a QA conference several years ago but it has broaden the range of acceptable topics to include development, devops and agile. I was at the first two editions and then didn't attend for a while until last year when I really liked it. The event is entirely in English with lots of foreign speakers.

Recently I've been working on something I call "Regression Test Monitoring" and my intention is to present this at ISTA 2017 so stay tuned.

November - Google Test Automation Conference, London

There are no dates announced for GTAC 2017 but it will be held in London. Both speakers and attendees are pre-approved and my goal is to be the second Bulgarian to speak at GTAC.

The previous two years saw talks about mutation testing vs. coverage and their respective use to determine the quality of a test suite with both parties arguing against each other. Since I'm working in both of these fields and have at least one practical example I'm trying to gather more information and present my findings to the world.

Thanks for reading and see you around!

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QA & Automation 101 Retrospective

QA 101 graduation

At the beginning of this year I've hosted the first QA related course at HackBulgaria. This is a long overdue post about how the course went, what worked well and what didn't. Brace yourself because it is going to be a long one.

The idea behind a QA course has been lurking in both RadoRado's (from HackBulgaria) and my heads for quite a while. We've been discussing it at least a year before we actually started. One day Rado told me he'd found a sponsor and we have the go ahead for the course and that's how it all started!

The first issue was that we weren't prepared to start at a moments notice. I literally had two weeks to prepare the curriculum and initial interview questions. Next we opened the application form and left it open until the last possible moment. I've been reviewing candidate answers hours before the course started, which was another mistake we made!

On the positive side is that I hosted a Q&A session on YouTube answering general questions about the profession and the course itself. This live stream helped popularize the course.

At the start we had 30 people and around 13 of them managed to "graduate" till the final lesson. The biggest portion of students dropped out after the first 5 lessons of Java crash course! Each lesson was around 4 hours with 20-30 minutes break in the middle.

With respect to the criteria find a first job or find a new/better job I consider the training successful. To my knowledge all students have found better jobs, many of them as software testers!

On the practical side of things students managed to find and report 11 interesting bugs against Fedora. Mind you that these were all found in the wild: fedora-infrastructure #5323, RHBZ#1339701, RHBZ#1339709, RHBZ#1339713, RHBZ#1339719, RHBZ#1339731, RHBZ#1339739, RHBZ#1339742, RHBZ#1339746, RHBZ#1340541, RHBZ#1340891.

Then students also made a few pull requests on GitHub (3 which I know off): commons-math #38, commons-csv #12, commons-email #1.

Lesson format

For reference most lessons were a mix of short presentation about theory and best practices followed by discussions and where appropriate practical sessions with technology or projects. The exercises were designed for individual work, work in pairs or small groups (4-5) on purpose.

By request from the sponsors I've tried to keep a detailed record of each student's performance and personality traits as much as I was able to observe them. I really enjoyed keeping such a journal but didn't share this info with my students which I consider a negative issue. I think knowing where your strong and weak areas are would help you become a better expert in your field!

Feedback from students

  • There was little time (to work on the practical examples I guess);
  • Not having particular practical tasks was a problem. For example we didn't have tasks of the sort do "X" then "Y";
  • They needed more time and more attention to be given to them;
  • Installing different pieces of software and tools took a lot of time and frustration. It was also quite problematic sometimes depending on whether they used Linux, Windows or Mac OS X;
  • Working with Eclipse IDE was horrible. Nobody new what to do and the interface wasn't newbie friendly. Also it took quite a lot of time to install dependencies and/or import projects to run in Eclipse;
  • There were a few problems with Selenium and its different versions being used.

I have to point out that while these are valid concerns and major issues students were at least partially guilty for the last 3 of them. It was my impression that most of them didn't prepare at home, didn't read the next lesson and didn't install prerequisite tools and software!

5x Java Crash Course

We've started with a Java crash course as requested by our sponsors which was extended to 5 instead of the original 3 sessions. RadoRado was teaching Java fundamentals while I was assisting him with comments.

On the good side is that Rado explains very well and in much details. He also writes code to demonstrate what he teaches and while doing so uses only the knowledge he's presented so far. For example if there's a repeating logic/functionality he would just write it twice instead of refactoring that into a separate function with parameters (assuming the students have not learned about functions yet). I think this made it more easier to understand the concepts being taught.

Another positive thing we did was me going behind Rado's computer and modifying some of the code while he was explaining something on screen. If you take the above example and have two methods with print out salutations, e.g. "Good morning, Alex" I would go and modify one of them to include "Mr." while the other will not. This introduced a change in behavior which ultimately results in a bug! This was a nice practical way to demonstrate how some classes of bugs get introduced in reality. We did only a few of these behind the computer changes and I definitely liked them! They were all ad-hoc, not planned for.

On the negative side Java seems hard to learn and after these 5 lessons half of the students dropped out. Maybe part of the reason is they didn't expect to start a QA course with lessons about programming. But that also means they didn't pay enough attention to the curriculum, which was announced in advance!

Lesson 01 - QA Fundamentals

I had made a point to assign time constraints to each exercise in the lessons. While that mostly worked in the first few lessons, where there is more theory, we didn't keep the schedule and were overtime.

Explaining testing theory (based on ISTQB fundamentals) took longer than I expected. it was also evident that we needed more written examples of what different test analysis techniques are (e.g. boundary value analysis). Here Petar Sabev helped me deliver few very nice examples.

One of the exercises was "when to stop testing" with an example of a Sudoku solving function and different environments in which this code operates, e.g. browser, mobile, etc. Students appeared to have a hard time understanding what a "runtime environment" is and define relevant tests based on that! I believe most of the students, due to lack of knowledge and experience, were also having a hard time grasping the concept of non-functional testing.

A positive thing was that students started explaining to one another and giving examples for bugs they've seen outside the course.

Lesson 02 - Software Development Lifecycle

This lesson was designed as role playing game to demonstrate the most common software development methodologies - waterfall and agile and discuss the QA role in both of them. The format by itself is very hard to conduct successfully and this was my first time ever doing this. I've also never taken part of such games until then, only heard about them.

During the waterfall exercise it was harder for the students to follow the game constraints and not exchange information with one another because they were sitting on the same table.

On the positive side all groups came with unique ideas about software features and how they want to develop them. Timewise we managed to do very well. On the negative side is that I was the client for all groups and didn't manage to pay enough attention to everyone, which btw is what clients usually do in real life.

Lesson 03 - Bug Tracking

This lesson was a practical exercise in writing bug reports and figuring out what information needs to be present in a good bug report. Btw this is something I always ask junior members at job interviews.

First we started with working in pairs to define what a good bug report is without actually knowing what that means. Students found it hard to brainstorm together and most of them worked alone during this exercise.

Next students had to write bug reports for some example bugs, which I've explained briefly on purpose and perform peer reviews of their bugs. Reviews took a long time to complete but overall students had a good idea of what information to include in a bug report.

Then, after learning from their mistakes and hearing what others had done, they've learned about some good practices and were tasked to rewrite their bug reports using the new knowledge. I really like the approach of letting students make some mistakes and then showing them the easier/better way of doing things. This is also on-par with Ivan Nemytchenko's methodology of letting his interns learn by their mistakes.

All bug reports can be found in students repositories, which are forked from the curriculum. Check out

I should have really asked everyone to file bugs under the curriculum repository so it is easier for me to track them. On the other hand I wanted each student to start building their own public profile to show potential employers.

Lesson 04 - Test Case Management

This lesson started with an exercise asking students to create accounts for Red Hat's OpenShift cloud platform in the form of a test scenario. The scenario intentionally left out some details. The idea being that missing information introduces inconsistencies during testing and to demonstrate how the same steps were performed slightly differently.

We had some troubles explaining exactly "how did you test" because most inexperienced people would not remember all details about where they clicked, did they use the mouse or the keyboard, was the tab order correct, etc. Regardless students managed to receive different results and discover that some email providers were not supported.

The homework assignment was to create test plans and test cases in Nitrate at Unfortunately the system appears to be down ATM and I don't have time to investigate why. This piece of infrastructure was put together in 2 hours and I'm surprised it lasted without issues during the entire course.

2x Introduction to Linux

This was a crash course in Linux fundamentals and exercise with most common commands and text editors in the console. Most of the students were not prepared with virtual machines. We've also used a cloud provider to give students remote shell but the provider API was failing and we had to deploy docker containers manually. Overall infrastructure was a big problem but we somehow managed. Another problem was with ssh clients from Windows who generated keys in a format that our cloud provider couldn't understand.

Wrt commands and exercises students did well and managed to execute most of them on their own. That's very good for people who've never seen a terminal in their lives (more or less).

Lesson 05 - Testing Fedora 24(25) Changes

Once again nobody was prepared with a virtual machine with Fedora and students were installing software as we go. Because of that we didn't manage to conduct the lesson properly and had to repeat it on the next session.

Rawhide being the bleeding edge of Fedora means it is full of bugs. Well I couldn't keep up with everyone and explain workarounds or how to install/upgrade Fedora. That was a major setback. It also became evident that you can't move quickly if you have no idea what to do and no instructions about it either.

Lesson 05 - Again

Once prepared with the latest and greatest from Rawhide the task was to analyze the proposed feature changes (on the Fedora wiki) and create test plans and design test cases for said changes. Then execute the tests in search for bugs. This is where some of the bugs above came from. The rest were found during upgrades.

This lesson was team work (4-5 students) but the results were mixed. IMO Fedora changes are quite hard to grasp, especially if you lack domain knowledge and broader knowledge about the structure and operation of a Linux distribution. I don't think most teams were able to clearly understand their chosen features and successfully create good plans/scenarios for them. On the other hand in real life software you don't necessarily understand the domain better and know what to do. I've been in situations where whole features have been defined by a single sentence and requested to be tested by QA.

One of the teams didn't manage to install Fedora (IIRC they didn't have laptops capable of running a VM) and were not able to conduct the exercise.

Being able to find real life bugs, some of them serious, and getting traction in Bugzilla is the most positive effect of this lesson. I personally wanted to have more output (e.g. more bugs, more cases defined, etc) but taking into account the blocking factors and setbacks I think this is a good initial result.

Lesson 06 - Unit Testing and Continuous Integration

Here we had a few examples of bad stubs and mocks which were not received very well. The topic is hard in itself and wasn't very well explained with practical examples.

Another negative thing is that students took a lot of time to fiddle around with Eclipse, they were mistyping commands in the terminal and generally not paying enough attention to instructions. This caused the exercises to go slowly.

We've had an exercise which asks the student to write a new test for a non-existing method. Then implement the method and make sure all the tests passed. You guessed it this is Test Driven Development. IIRC one of the students was having a hard time with that exercise so I popped up my editor on the large screen and started typing what she told me, then re-running the tests and asking her to show me the errors I've made and tell me how to correct them. The exercise was received very well and was fun to do.

Due to lack of time we had to go over TravisCI very quickly. The other bad thing about TravisCI is that it requires git/GitHub and the students were generally inexperienced with that. Both GitHub for Windows and Mac OS suck a big time IMO. What you need is the console. However none of the students had any practical experience with git and knew how to commit code and push branches to GitHub. git fundamentals however is a separate one or two lessons by itself which we didn't do.

Lesson 07 - Writing JUnit tests for Apache Commons

Excluding the problems with Eclipse and the GitHub desktop client and missing instructions for Windows the hardest part of this lesson was actually selecting a component to work on, understanding what the code does and actually writing meaningful tests. On top of that most students were not very proficient programmers and Java was completely new to them.

Despite having 3 pull requests on GitHub I consider this lesson to be a failure.

Lesson 08 - Integration Testing with Selenium

This lesson starts with an example of what a flaky test it. At the moment I don't think this lesson is the best place for that example. To make things even more difficult the example is in Python (because that way was the easiest for me to write it) instead of Java. Students had problems installing Python on Windows just to make this example work. They also were lacking the knowledge how to execute a script in the terminal.

One of the students proposed a better flaky example utilizing dates and times and executing it during various hours of the day. I have yet to code this and prepare environment in which it would be executed. Btw recently I've seen similar behavior caused by inconsistent timezone usage in Ruby which resulted in unexpected time offset a little after midnight :).

Once again I have to point out that students came generally unprepared for the lesson and haven't installed prerequisite software and programming languages. This is becoming a trend and needs to be split out into a preparation session, possibly with a check list.

On the Selenium side, starting with Selenium IDE, it was a bit unclear how to use it and what needs to be done. This is another negative trend, where students were missing clear instructions what they are expected to do. At the end we did resort to live demo using Selenium IDE so they can at least get some idea about it.

Lesson 09 and 10 - Writing Selenium tests for Mozilla Add-ons website

IMO these two lessons are the biggest disaster of the entire course. Python & virtualenv on Windows was a total no go but on Linux things weren't much easier because students had no idea what a virtualenv is.

Practice wise they haven't managed to read all the bugs on the Mozilla bug tracker and had a very hard time selecting bugs to write tests for. Not to mention that many of the reported bugs were administrative tasks to create or remove add-on categories. There weren't many functional related bugs to write tests for.

The product under test was also hard to understand and most students were seeing it for the first time, let alone getting to know the devel and testing environments that Mozilla provides. Mozilla's test suite being in Python is just another issue to make contribution harder because we've never actually studied Python.

Between the two lessons there were students who've missed the Selenium introduction lesson and were having even harder time to figure things out. I didn't have the time to explain and go back to the previous lesson for them. Maybe an attendance policy is needed for dependent lessons.

Before the course started I've talked to some guys at Mozilla's IRC channel and they agreed to help but at the end we didn't even engage with them. At this point I'm skeptical that mentoring over IRC would have worked anyway.

Lesson 11 - Introduction to Performance Testing

This was a more theoretical lesson with less practical examples and exercises. I have provided some blog posts of mine related to the topic of performance testing but in general they are related to software that I've used which isn't generally known to a less experienced audience (Celery, Twisted). These blog posts IMO were hard to put into perspective and didn't serve a good purpose as examples.

The practical part of the lesson was a discussion with the goal of creating a performance testing strategy for GitHub's infrastructure. It was me who was doing most of the talking because students have no experience working on such a large infrastructure like GitHub and didn't know what components might be there, how they might be organized (load balancers, fail overs, etc) and what needs to be tested.

There was also a more practical example to create a performance test in Java for one of the classes found in commons-codec/src/main/java/org/apache/commons/codec/digest. Again the main difficulty here was working fluently with Eclipse, getting the projects to build/run and knowing how the software under test was supposed to work and be executed.

Lesson 12 - How to find 1000 bugs in 30 minutes

This was a more relaxed lesson with examples of simple types of bugs found on a large scale. Most examples came from my blog and experiments I've made against Fedora.

While amusing and fun I don't think all of the students understood me and kept their attention. Part of that is because Fedora tends to focus on low level stuff and my examples were not necessarily easy to understand.

Feedback from the sponsor

Experian Bulgaria was the exclusive sponsor for this course. At the end of the summer Rado and I met with them to discuss the results of the training. Here's what they say

  • Overall technical knowledge they consider to be weak. What they need are people with basic knowledge in the field of object oriented programming, databases, operating systems and networking. These are skills candidates need in order to work for Experian. It must be noted that most of them were not taught at this course!
  • English language proficiency for all students is low on average;
  • User level experience with Linux was fine but students were missing deeper knowledge about the operating system. Once again something we didn't teach;
  • The programming languages favored at Experian are Java and Ruby and students had poor knowledge of them. They also had weak understanding of OOP principles;
  • According to Experian students were more ingrained with the development mindset and were trying their luck in the QA profession instead of genuinely being interested in the field. While this is generally the case I have to point out that as sponsor Experian did a poor job at promoting their company and the QA profession as a whole. What isn't known to the general public is their big in-house QA community which could have served as a source of inspiration for the students!
  • Low motivation and lack of fundamental knowledge from university are other traits interviewers at Experian have identified. They argued for a stronger acceptance process and a requirement of minimum 2 years of university education in computer science.

On the topic of testing knowledge candidates did mostly OK, however we don't have enough information about this. Also the hiring process at Experian is more focused on the broader knowledge areas listed above so substantial improvement in the testing knowledge of candidates doesn't given them much head start.

While to my knowledge they didn't hire anyone few people received an offer but declined due to various personal reasons. I view this as poor performance on our side but Experian thinks otherwise and are willing to sponsor another round of training.


Here is a list of all the things that could be improved

  • Take time to develop the curriculum and have it pass QA review by other experienced testers (in particular such that also teach students);
  • Make the application process harder to include people with broader IT knowledge;
  • Allow time to review all applicants;
  • Find a co-trainer and additional mentors for some of the exercises;
  • Minimize the number of students accepted in the course so we can handle everyone with more care;
  • Give homework assignments and examine them before each lesson;
  • Collect and provide performance review at the end of the course;
  • Minimize the technology stack and tools used;
  • Host a technology preparation session at the beginning paired with a check list of all the things that need to be done. Very likely make the chosen technology stack a hard requirement to avoid setbacks later in the schedule;
  • We need more fundamental lessons like practical git tutorial, practical Linux tutorial, databases, networking, etc.
  • Same goes for Java or any other programming language. Each of these technologies easily makes a course by itself. Possibly include technology skill assessment in the application form and reject candidates who don't meet the minimum level. This is to ensure the group is able to move at the same pace.
  • We need to improve the infrastructure used during the course, especially exercise bug tracking and test case management systems;
  • Students need clear instructions for every exercise - what is required from them, what the expected result is and what they need to be doing, etc;
  • Provide more examples for just about everything. Also make the examples easier to understand/simple with the harder examples left for further reading;
  • Provide easier projects to work on. This means applications whose domain is easier to understand and closer to what experiences the students might have. Also projects need clear instructions how to join and how to contribute with tests.
  • The same application/software needs to be used for manual bug finding, unit test writing and integration test with Selenium. This will minimize both context and technology switches and allow to view various testing activities in the context of a single software under test;
  • While using open source projects for the above listed purposes sounds great the reality is that they are hard to join and will not move according to our schedule. Maybe less focus on open source per-se and more focus on a particular application under test. Instructors can then proxy all the tests forward to the upstream community;
  • Focus more on practice and less on exotic topics like performance testing and large scale bug finding;
  • Seek more active participation from sponsors!

If you have suggestions please comment below, especially if you can tell me how to implement them in practice.

Thanks for reading and happy testing!

There are comments.

4 Quick Wins to Manage the Cost of Software Testing

Every activity in software development has a cost and a value. Getting cost to
trend down while increasing value, is the ultimate goal.

This is the introduction of an e-book called 4 Quick Wins to Manage the Cost of Software Testing. It was sent to me by Ivan Fingarov couple of months ago. Just now I've managed to read it and here's a quick summary. I urge everyone to download the original copy and give it a read.

The paper focuses on several practices which organizations can apply immediately in order to become more efficient and transparent in their software testing. While larger organizations (e.g. enterprises) have most of these practices already in place smaller companies (up to 50-100 engineering staff) may not be familiar with them and will reap the most benefits of implementing said practices. Even though I work for a large enterprise I find this guide useful when considered at the individual team level!

The first chapter focuses on Tactics to minimize cost: Process, Tools, Bug System Mining and Eliminating Handoffs.

In Process the goal is to minimize the burden of documenting the test process (aka testing artifacts), allow for better transparency and visibility outside the QA group and streamline the decision making process of what to test and when to stop testing, how much has been tested, what the risk is, ect. The authors propose testing core functionality paired with emerging risk areas based on new features development. They propose making a list of these and sorting that list by perceived risk/priority and testing as much as possible. Indeed this is very similar to the method I've used at Red Hat when designing testing for new features and new major releases of Red Hat Enterprise Linux. A similar method I've seen in place at several start-ups as well, although in the small organization the primary driver for this method is lack of sufficient test resources.

Tools proposes the use of test case management systems to ease the documentation burden. I've used TestLink and Nitrate. From them Nitrate has more features but is currently unmaintained with me being the largest contributor on GitHub. From the paid variants I've used Polarion which I generally dislike. Polarion is most suitable for large organizations because it gives lots of opportunities for tracking and reporting. For small organizations it is an overkill.

Bug System Mining is a technique which involves regularly scanning the bug tracker and searching for patterns. This is useful for finding bug types which appear frequently and generally point to a flaw in the software development process. The fix for these flaws usually is a change in policy/workflow which eliminates the source of the errors. I'm a fan of this technique when joining an existing project and need to assess what the current state is. I've done this when consulting for a few start-ups, including Jitsi Meet (acquired by Atlassian), however I'm not doing bug mining on a regular basis which I consider a drawback and I really should start doing!

For example at one project I found lots of bugs reported against translations, e.g. missing translations, text overflowing the visible screen area or not playing well with existing design, chosen language/style not fitting well with the product domain, etc.

The root cause of the problem was how the software in question has been localized. The translators were given a file of English strings, which they would translate and return back in an spread sheet. Developers would copy&paste the translated strings into localization files and integrate with the software. Then QA would usually inspect all the pages and report the above issues. The solution was to remove devel and QA from the translation process, implement a translation management system together with live preview (web based) so that translators can keep track of what is left to translate and can visually inspect their work immediately after a string was translated. Thus translators are given more context for their work but also given the responsibility to produce good quality translations.

Another example I've seen are many bugs which seem like a follow up/nice to have features of partially implemented functionality. The root cause of this problem turned out to be that devel was jumping straight to implementation without taking the time to brainstorm and consult with QE and product owners, not taking into account corner cases and minor issues which would have easily been raised by skillful testers. This process lead to several iterations until the said functionality was considered initially implemented.

Eliminating Handoffs proposes the use of cross-functional teams to reduce idle time and reduce the back-and-forth communication which happens when a bug is found, reported, evaluated and considered for a fix, fixed by devel and finally deployed for testing. This method argues that including testers early in the process and pairing them with the devel team will produce faster bug fixes and reduce communication burden.

While I generally agree with that statement it's worth noting that cross-functional teams perform really well when all team members have relatively equal skill level on the horizontal scale and strong experience on the vertical scale (think T-shaped specialist). Cross-functional teams don't work well when you have developers who aren't well versed in the testing domain and/or testers who are not well versed in programming or the broader OS/computer science fundamentals domain. In my opinion you need well experienced engineers for a good cross-functional team.

In the chapter Collaboration the paper focuses on pairing, building the right thing and faster feedback loops for developers. This overlaps with earlier proposals for cross-functional teams and QA bringing value by asking the "what if" questions. The chapter specifically talks about the Three Amigos meeting between PM, devel and QA where they discuss a feature proposal from all angles and finally come to a conclusion what the feature should look like. I'm a strong supporter of this technique and have been working with it under one form or another during my entire career. This also touches on the notion that testers need to move into the Quality Assistance business and be proactive during the software development process, which is something I'm hoping to talk about at the Romanian Testing Conference next year!

Finally the book talks about Skills Development and makes the distinction between Centers of Excellence (CoE) and Communities of Practice (CoP). Both the book and I are supporters of the CoP approach. This is a bottoms-up approach which is open for everyone to join in and harnesses the team creative abilities. It also takes into account that different teams use different methods and tools and that "one size doesn't fit all"!

Skilled teams find important bugs faster, discover innovative solutions to hard
testing problems and know how to communicate their value. Sometimes, a few super
testers can replace an army of average testers.

While I consider myself to be a "super tester" with thousands of bugs reported there is a very important note to make here. Communities of Practice are successful when their members are self-focused on skill development! In my view and to some extent the communities I've worked with everyone should strive to constantly improve their skills but also exercise peer pressure on their co-workers to not fall behind. This has been confirmed by other folks in the QA industry and I've heard it many times when talking to friends from other companies.

Thanks for reading and happy testing!

There are comments.

Mutation Testing vs. Coverage

At GTAC 2015 Laura Inozemtseva made a lightning talk titled Coverage is Not Strongly Correlated with Test Suite Effectiveness which is the single event that got me hooked up with mutation testing. This year, at GTAC 2016, Rahul Gopinath made a counter argument with his lightning talk Code Coverage is a Strong Predictor of Test Suite Effectiveness. So which one is better ? I urge you to watch both talks and take notes before reading about my practical experiment and other opinions on the topic!

DISCLAIMER: I'm a heavy contributor to Cosmic-Ray, the mutation testing tool for Python so my view is biased!

Both Laura and Rahul (you will too) agree that a test suite effectiveness depends on the strength of its oracles. In other words the assertions you make in your tests. This is what makes a test suite good and determines its ability to detect bugs when present. I've decided to use pelican-ab as a practical example. pelican-ab is a plugin for Pelican, the static site generator for Python. It allows you to generate A/B experiments by writing out the content into different directories and adjusting URL paths based on the experiment name.

Can 100% code coverage detect bugs

Absolutely NOT! In version 0.2.1, commit ef1e211, pelican-ab had the following bug:

Given: Pelican's DELETE_OUTPUT_DIRECTORY is set to True (which it is by default)
When: we generate several experiments using the commands:
    AB_EXPERIMENT="control" make regenerate
    AB_EXPERIMENT="123" make regenerate
    AB_EXPERIMENT="xy" make regenerate
    make publish
Actual result: only the "xy" experiment (the last one) would be published online.
And: all of the other contents will be deleted.

Expected result: content from all experiments will be available under the output directory.

This is because before each invocation Pelican deletes the output directory and re-creates the entire content structure. The bug was not caught regardless of having 100% line + branch coverage. See Build #10 for more info.

Can 100% mutation coverage detect bugs

So I've branched off since commit ef1e211 into the mutation_testing_vs_coverage_experiment branch (requires Pelican==3.6.3).

After initial execution of Cosmic Ray I have 2 mutants left:

$ cosmic-ray run --baseline=10 --test-runner=unittest example.json pelican_ab -- tests/
$ cosmic-ray report example.json 
job ID 29:Outcome.SURVIVED:pelican_ab
command: cosmic-ray worker pelican_ab mutate_comparison_operator 3 unittest -- tests/
--- mutation diff ---
--- a/home/senko/pelican-ab/pelican_ab/
+++ b/home/senko/pelican-ab/pelican_ab/
@@ -14,7 +14,7 @@
     def __init__(self, output_path, settings=None):
         super(self.__class__, self).__init__(output_path, settings)
         experiment = os.environ.get(jinja_ab._ENV, jinja_ab._ENV_DEFAULT)
-        if (experiment != jinja_ab._ENV_DEFAULT):
+        if (experiment > jinja_ab._ENV_DEFAULT):
             self.output_path = os.path.join(self.output_path, experiment)
             Content.url = property((lambda s: ((experiment + '/') + _orig_content_url.fget(s))))
             URLWrapper.url = property((lambda s: ((experiment + '/') + _orig_urlwrapper_url.fget(s))))

job ID 33:Outcome.SURVIVED:pelican_ab
command: cosmic-ray worker pelican_ab mutate_comparison_operator 7 unittest -- tests/
--- mutation diff ---
--- a/home/senko/pelican-ab/pelican_ab/
+++ b/home/senko/pelican-ab/pelican_ab/
@@ -14,7 +14,7 @@
     def __init__(self, output_path, settings=None):
         super(self.__class__, self).__init__(output_path, settings)
         experiment = os.environ.get(jinja_ab._ENV, jinja_ab._ENV_DEFAULT)
-        if (experiment != jinja_ab._ENV_DEFAULT):
+        if (experiment not in jinja_ab._ENV_DEFAULT):
             self.output_path = os.path.join(self.output_path, experiment)
             Content.url = property((lambda s: ((experiment + '/') + _orig_content_url.fget(s))))
             URLWrapper.url = property((lambda s: ((experiment + '/') + _orig_urlwrapper_url.fget(s))))

total jobs: 33
complete: 33 (100.00%)
survival rate: 6.06%

The last one, job 33 is equivalent mutation. The first one, job 29 is killed by the test added in commit b8bff85. For all practical purposes we now have 100% code coverage and 100% mutation coverage. The bug described above still exists thought.

How can we detect the bug

The bug isn't detected by any test because we don't have tests designed to perform and validate the exact same steps that a physical person will execute when using pelican-ab. Such test is added in commit ca85bd0 and you can see that it causes Build #22 to fail.

Experiment with setting DELETE_OUTPUT_DIRECTORY=False in tests/ and the test will PASS!

Is pelican-ab bug free

Not of course. Even after 100% code and mutation coverage and after manually constructing a test which mimics user behavior there is at least one more bug present. There is a pylint bad-super-call error, fixed in commit 193e3db. For more information about the error see this blog post.

Other bugs found

During my humble experience with mutation testing so far I've added quite a few new tests and discovered two bugs which went unnoticed for years. The first one is constructor parameter not passed to parent constructor, see PR#96, pykickstart/commands/

     def __init__(self, writePriority=0, *args, **kwargs):
-        KickstartCommand.__init__(self, *args, **kwargs)
+        KickstartCommand.__init__(self, writePriority, *args, **kwargs)
         self.authconfig = kwargs.get("authconfig", "")

The second bug is parameter being passed to parent class constructor, but the parent class doesn't care about this parameter. For example PR#96, pykickstart/commands/

-    def __init__(self, writePriority=0, *args, **kwargs):
-        BaseData.__init__(self, writePriority, *args, **kwargs)
+    def __init__(self, *args, **kwargs):
+        BaseData.__init__(self, *args, **kwargs)

Also note that pykickstart has nearly 100% test coverage as a whole and the affected files were 100% covered as well.

The bugs above don't seem like a big deal and when considered out of context are relatively minor. However pykickstart's biggest client is anaconda, the Fedora and Red Hat Enterprise Linux installation program. Anaconda uses pykickstart to parse and generate text files (called kickstart files) which contain information for driving the installation in a fully automated manner. This is used by everyone who installs Linux on a large scale and is pretty important functionality!

writePriority controls the order of which individual commands are written to file at the end of the installation. In rare cases the order of commands may depend on each other. Now imagine the bugs above produce a disordered kickstart file, which a system administrator thinks should work but it doesn't. It may be the case this administrator is trying to provision hundreds of Linux systems to bootstrap a new data center or maybe performing disaster recovery. You get the scale of the problem now, don't you?

To be honest I've seen bugs of this nature but not in the last several years.

This is all to say a minor change like this may have an unexpectedly big impact somewhere down the line.


With respect to the above findings and my bias I'll say the following:

  • Neither 100% coverage, nor 100% mutation coverage are a silver bullet against bugs;
  • 100% mutation coverage appears to be better than 100% code coverage in practice;
  • Mutation testing clearly shows out pieces of code which need refactoring which in turn minimizes the number of possible mutations;
  • Mutation testing causes you to write more asserts and construct more detailed tests which is always a good thing when testing software;
  • You can't replace humans designing test cases just yet but can give them tools to allow them to write more and better tests;
  • You should not rely on a single tool (or two of them) because tools are only able to find bugs they were designed for!

Bonus: What others think

As a bonus to this article let me share a transcript from the community:

atodorov 2:28 PM
Hello everyone, I'd like to kick-off a discussion / interested in what you think about
Rahul Gopinath's talk at GTAC this year. What he argues is that test coverage is still
the best metric for how good a test suite is and that mutation coverage doesn't add much
additional value. His talk is basically the opposite of what @lminozem presented last year
at GTAC. Obviously the community here and especially tools authors will have an opinion on
these two presentations.

tjchambers 12:37 AM
@atodorov I have had the "pleasure" of working on a couple projects lately that illustrate
why LOC test coverage is a misnomer. I am a **strong** proponent of mutation testing so will
declare my bias.

The projects I have worked on have had a mix of test coverage - one about 50% and
another > 90%.

In both cases however there was a significant difference IMO relative to mutation coverage
(which I have more faith in as representative of true tested code).

Critical factors I see when I look at the difference:

- Line length: in both projects the line lengths FAR exceeded visible line lengths that are
"acceptable". Many LONGER lines had inline conditionals at the end, or had ternary operators
and therefore were in fact only 50% or not at all covered, but were "traversed"

- Code Conviction (my term): Most of the code in these projects (Rails applications) had
significant Hash references all of which were declared in "traditional" format hhh[:symbol].
So it was nearly impossible for the code in execution to confirm the expectation of the
existence of a hash entry as would be the case with stronger code such as "hhh.fetch(:symbol)"

- Instance variables abound: As with most of Rails code the number of instance variables
in a controller are extreme. This pattern of reference leaked into all other code as well,
making it nearly impossible with the complex code flow to ascertain proper reference
patterns that ensured the use of the instance variables, so there were numerous cases
of instance variable typos that went unnoticed for years. (edited)

- .save and .update: yes again a Rails issue, but use of these "weak" operations showed again
that although they were traversed, in many cases those method references could be removed
during mutation and the tests would still pass - a clear indication that save or update was
silently failing.

I could go on and on, but the mere traversal of a line of code in Ruby is far from an indication
of anything more than it may be "typed in correctly".

@atodorov Hope that helps.

LOC test coverage is a place to begin - NOT a place to end.

atodorov 1:01 AM
@tjchambers: thanks for your answer. It's too late for me here to read it carefully but
I'll do it tomorrow and ping you back

dkubb 1:13 AM
As a practice mutation testing is less widely used. The tooling is still maturing. Depending on your
language and environment you might have widely different experiences with mutation testing

I have not watched the video, but it is conceivable that someone could try out mutation testing tools
for their language and conclude it doesn’t add very much

mbj 1:14 AM
Yeah, I recall talking with @lminozem here and we identified that the tools she used likely
show high rates of false positives / false coverage (as the tools likely do not protect against
certain types of integration errors)

dkubb 1:15 AM
IME, having done TDD for about 15+ years or so, and mutation testing for about 6 years, I think
when it is done well it can be far superior to using line coverage as a measurement of test quality

mbj 1:16 AM
Any talk pro/against mutation testing must, as the tool basis is not very homogeneous, show a non consistent result.

dkubb 1:16 AM
Like @tjchambers says though, if you have really poor line coverage you’re not going to
get as much of a benefit from mutation testing, since it’s going to be telling you what
you already know — that your project is poorly tested and lots of code is never exercised

mbj 1:19 AM
Thats a good and likely the core point. I consider that mutation testing only makes sense
when aiming for 100% (and this is to my experience not impractical).

tjchambers 1:20 AM
I don't discount the fact that tool quality in any endeavor can bring pro/con judgements
based on particular outcomes

dkubb 1:20 AM
What is really interesting for people is to get to 100% line coverage, and then try mutation
testing. You think you’ve done a good job, but I guarantee mutation testing will find dozens
if not hundreds of untested cases .. even in something with 100% line coverage

To properly evaluate mutation testing, I think this process is required, because you can’t
truly understand how little line coverage gives you in comparison

tjchambers 1:22 AM
But I don't need a tool to tell me that a 250 character line of conditional code that by
itself would be an oversized method AND counts more because there are fewer lines in the
overall percentage contributes to a very foggy sense of coverage.

dkubb 1:22 AM
It would not be unusual for something with 100% line coverage to undergo mutation testing
and actually find out that the tests only kill 60-70% of possible mutations

tjchambers 1:22 AM
@dkubb or less

dkubb 1:23 AM
usually much less :stuck_out_tongue:

it can be really humbling

mbj 1:23 AM
In this discussion you miss that many test suites (unless you have noop detection):
Will show false coverage.

tjchambers 1:23 AM
When I started with mutant on my own project which I developed I had 95% LOC coverage

mbj 1:23 AM
Test suites need to be fixed to comply to mutation testing invariants.

tjchambers 1:23 AM
I had 34% mutation coverage

And that was ignoring the 5% that wasn't covered at all

mbj 1:24 AM
Also if the tool you compare MT with line coverage on: Is not very strong,
the improvement may not be visible.

dkubb 1:24 AM
another nice benefit is that you will become much better at enumerating all
the things you need to do when writing tests

tjchambers 1:24 AM
@dkubb or better yet - when writing code.

The way I look at it - the fewer the alive mutations the better the test,
the fewer the mutations the better the code.

dkubb 1:29 AM
yeah, you can infer a kind of cyclomatic complexity by looking at how many mutations there are

tjchambers 1:31 AM
Even without tests (not recommended) you can judge a lot from the mutations themselves.

I still am an advocate for mutations/LOC metric

As you can see members in the community are strong supporters of mutation testing, all of them having much more experience than I do.

Please help me collect more practical examples! My goal is to collect enough information and present the findings at GTAC 2017 which will be held in London.

Thanks for reading and happy testing!

There are comments.

How to create auxiliary build jobs in Travis-CI matrix

Auxiliary build job in Travis-CI

In Travis-CI when you combine the three main configuration options of Runtime (language), Environment and Exclusions/Inclusions you get a build matrix of all possible combinations! For example, for django-chartit the matrix includes 43 build jobs, spread across various Python and Django versions. For reference see Build #75.

For django-chartit I wanted to have an additional build job which would execute pylint. I wanted the job to be independent because currently pylint produces lots of errors and warnings. Having an independent job instead of integrating pylint together with all jobs makes it easier to see if any of the functional tests failed.

Using the inclusion functionality of Travis-CI I was able to define an auxiliary build job. The trick is to provide sane environment defaults for all build jobs (regular and auxiliary ones) so you don't have to expand your environment section! In this case the change looks like this

diff --git a/.travis.yml b/.travis.yml
index 67f656d..9b669f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,8 @@ after_success:
 - coveralls
 - pip install coveralls
+- if [ -z "$_COMMAND" ]; then export _COMMAND=coverage; fi
+- if [ -z "$_DJANGO" ]; then export _DJANGO=1.10.4; fi
 - !!python/unicode '_DJANGO=1.10'
 - !!python/unicode '_DJANGO=1.10.2'
@@ -41,6 +43,10 @@ matrix:
     python: 3.3
   - env: _DJANGO=1.10.4
     python: 3.3
+  include:
+  - env: _COMMAND=pylint
+    python: 3.5
     on_failure: change
@@ -50,4 +56,4 @@ python:
 - 3.3
 - 3.4
 - 3.5
-script: make coverage
+script: make $_COMMAND

For more info take a look at commit b22eda7 and Build #77. Note Job #77.44!

Thanks for reading and happy testing!

There are comments.

Overridden let() causes segfault with RSpec

Last week Anton asked me to take a look at one of his RSpec test suites. He was able to consistently reproduce a segfault which looked like this:

/home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:113: [BUG] vm_call_cfunc - cfp consistency error
ruby 2.3.2p217 (2016-11-15 revision 56796) [x86_64-linux]

-- Control frame information -----------------------------------------------
c:0013 p:---- s:0048 e:000047 CFUNC  :map
c:0012 p:0011 s:0045 e:000044 BLOCK  /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:113
c:0011 p:0035 s:0043 e:000042 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/configuration.rb:1835
c:0010 p:0011 s:0040 e:000039 BLOCK  /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:112
c:0009 p:0018 s:0037 e:000036 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/reporter.rb:77
c:0008 p:0022 s:0033 e:000032 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:111
c:0007 p:0025 s:0028 e:000027 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:87
c:0006 p:0085 s:0023 e:000022 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:71
c:0005 p:0026 s:0016 e:000015 METHOD /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/runner.rb:45
c:0004 p:0025 s:0012 e:000011 TOP    /home/atodorov/.rbenv/versions/2.3.2/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/exe/rspec:4 [FINISH]
c:0003 p:---- s:0010 e:000009 CFUNC  :load
c:0002 p:0136 s:0006 E:001e10 EVAL   /home/atodorov/.rbenv/versions/2.3.2/bin/rspec:22 [FINISH]
c:0001 p:0000 s:0002 E:0000a0 (none) [FINISH]

Googling for vm_call_cfunc - cfp consistency error yields Ruby #10460. Comments on the bug and particularly this one point towards the error:

> Ruby is trying to be nice about reporting the error; but in the end,
> your code is still broken if it overflows stack.

Somewhere in the test suite was a piece of code that was overflowing the stack. It was somewhere along the lines of

describe '#active_client_for_user' do
  context 'matching an existing user' do
    it_behaves_like 'manager authentication' do
      include_examples 'active client for user with existing user'

Considering the examples in the bug I started looking for patterns where a variable was defined and later redefined, possibly circling back to the previous definition. Expanding the shared examples by hand transformed the code into

describe '#active_client_for_user' do
  context 'matching an existing user' do
    let(:user) { create(:user, :manager) }
    let!(:api_user_authentication) { create(:user_authentication, user: user) }
    let(:user) { api_user_authentication.user }

    context 'with an `active_assigned_client`' do
      ... skip ...

    ... skip ...

Line 5. overrode line 3. When line 4. was executed first because of lazy execution and the call execution path became: 4-5-4-5-4-5 ... NOTE: I think we need a warning about that in RuboCop, see RuboCop #3769. The fix however is a no brainer:

-  let(:user) { create(:user, :manager) }
-  let!(:api_user_authentication) { create(:user_authentication, user: user) }
+  let(:manager) { create(:user, :manager) }
+  let!(:api_user_authentication) { create(:user_authentication, user: manager) }

Thanks for reading and happy testing.

There are comments.

Highlights from ISTA and GTAC 2016

ISTA 2016

Another two weeks have passed and I'm blogging about another 2 conferences. This year both Innovations in Software Technologies and Automation and Google Test Automation Conference happened on the same day. I was attending ISTA in Sofia during the day and watching the live stream of GTAC during the evenings. Here are some of the things that reflected on me:

  • How can I build my software in order to make this a perfect day for the user ?
  • People are not the problem which causes bad software to exist. When designing software focus on what people need not on what technology is forcing them to do;
  • You need to have blind trust in the people you work with because all the times projects look like they are not going to work until the very end!
  • It's good to have diverse set of characters in the company and not homogenize people;
  • Team performance grows over time. Effective teams minimize time waste during bad periods. They (have and) extract value from conflicts!
  • One-on-one meetings are usually like status reports which is bad. Both parties should bring their own issues to the table;
  • To grow an effective team members need to do things together. For example pair programming, writing test scenarios, etc;
  • When teams don't take actions after retrospective meetings it is usually a sign of missing foundational trust;
  • QA engineers need to be present at every step of the software development life-cycle! This is something I teach my students and have been confirmed by many friends in the industry;
  • Agile is all about data, even when it comes to testing and quality. We need to decompose and measure iteratively;
  • Agile is also about really skillful people. One way to boost your skills is to adopt the T-shaped specialist model;
  • In agile iterative work and continuous delivery is king so QA engineers need to focus even more on visualization (I will also add documentation), refactoring and code reviews;
  • Agile teams need to give opportunities to team members for taking risk and taking ownership of their actions in the gray zone (e.g. actions which isn't clear who should be doing).

In the brave new world of micro services end to end testing is no more! We test each level in isolation but keep stable contracts/APIs between levels. That way we can reduce the test burden and still guarantee an acceptable level of risk. This change in software architecture (monolithic vs. micro) leads to change in technologies (one framework/language vs. what's best for the task) which in turn leads to changes in testing approach and testing tools. This ultimately leads to changing people on the team because they now need different skills than when they were hired! This circles back to the T-shaped specialist model and the fact that QA should be integrated in every step of the way! Thanks to Denitsa Evtimova and Lyudmila Labova for this wisdom and the quote pictured above.

Aneta Petkova talked about monitoring of test results which is a topic very close to my work. Imagine you have your automated test suite but still get failures occasionally. Are these bugs or something else broke ? If they are bugs and you are waiting for them to be fixed do you execute the tests against the still broken build or wait ? If you do, what additional info do you get from these executions vs. how much time do you spend figuring out "oh, that's still not fixed or geez, here's another hidden bug in the code" ?

Her team has modified their test execution framework (what I'd usually call a test runner or even test lab) to have knowledge about issues in JIRA and skip some tests when no meaningful information can be extracted from them. I have to point out that this approach may require a lot of maintenance in environments where you have failures due to infrastructure issues. This idea connects very nicely with the general idea behind this year's GTAC - don't run tests if you don't need to aka smart test execution!

Boris Prikhodskiy shared a very simple rule. Don't execute tests

  • which have 100 % pass rate;
  • during the last month;
  • and have been executed at least 100 times before that!

This is what Unity does for their numerous topic branches and reduces test time with 60-70 percent. All of the test suite is still executed against their trunk branch and PR merge queue branches!

At GTAC there were several presentations about speeding up test execution time. Emanuil Slavov was very practical but the most important thing he said was that a fast test suite is the result of many conscious actions which introduced small improvements over time. His team had assigned themselves the task to iteratively improve their test suite performance and at every step of the way they analyzed the existing bottlenecks and experimented with possible solutions.

The steps in particular are (on a single machine):

  • Execute tests in dedicated environment;
  • Start with empty database, not used by anything else; This also leads to adjustments in your test suite architecture and DB setup procedures;
  • Simulate and stub external dependencies like 3rd party services;
  • Move to containers but beware of slow disk I/O;
  • Run database in memory not on disk because it is a temporary DB anyway;
  • Don't clean test data, just trash the entire DB once you're done;
  • Execute tests in parallel which should be the last thing to do!
  • Equalize workload between parallel threads for optimal performance;
  • Upgrade the hardware (RAM, CPU) aka vertical scaling;
  • Add horizontal scaling (probably with a messaging layer);

John Micco and Atif Memon talked about flaky tests at Google:

  • 84% of the transitions from PASS to FAIL are flakes;
  • Almost 16% of their 3.5 million tests have some level of flakiness;
  • Flaky failures frequently block and delay releases;
  • Google spends between 2% and 16% of their CI compute resources re-running flaky tests;
  • Flakiness insertion speed is comparable to flakiness removal speed!
  • The optimal setting is 2 persons modifying the same source file at the same time. This leads to minimal chance of breaking stuff;
  • Fix or delete flaky tests because you don't get meaningful value out of them.

So Google want to stop a test execution before it is executed if historical data shows that the test has attributes of flakiness. The research they talk about utilizes tons of data collected from Google's CI environment which was the most interesting fact for me. Indeed if we use data to decide which features to build for our customers then why not use data to govern the process of testing? In addition to the video you should read John's post Flaky Tests at Google and How We Mitigate Them.

At the end I'd like to finish with Rahul Gopinath's Code Coverage is a Strong Predictor of Test suite Effectiveness in the Real World. He basically said that code coverage metrics as we know them today are still the best practical indicator of how good a test suite is. He argues that mutation testing is slow and only provides additional 4% to a well designed test suite. This is absolutely the opposite of what Laura Inozemtseva presented last year in her Coverage is Not Strongly Correlated with Test Suite Effectiveness lightning talk. Rahul also made a point about sample size in the two research papers and I had the impression he's saying Laura didn't do a proper academic research.

I'm a heavy contributor to Cosmic Ray, the mutation testing tool for Python and also use mutation testing in my daily job so this is a very interesting topic indeed. I've asked fellow tool authors to have a look at both presentations and share their opinions. I also have an idea about a practical experiment to see if full branch coverage and full mutation coverage will be able to find a known bug in a piece of software I wrote. I will be writing about this experiment next week so stay tuned.

Thanks for reading and happy testing!

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Women In Open Source

OpenFest 2016

It's been 2 weeks after OpenFest 2016 and I've promised to blog about what happened during the Women in Open Source presentation, which is the only single talk I did attend.

The presenters were Jona Azizaj, whom I met at FOSDEM earlier this year, Suela Palushi and Kristi Progri, all 3 from Albania. I've went to OpenFest specifically to meet them and listen to their presentation.

They started by explaining their background and telling us more about their respective communities, Fedora Women, WoMoz, GNOME Outreach and the Open Labs hackerspace in Tirana. The girls gave some stats how many women there are in the larger FOSS community and what some newcomer's first impressions could be.

Did you know that in 2002 1.1% of all FOSS participants were female, while in 2013 that was 11% ? A 10x increase but of them only 1.5% are developers.

The presentation was a nice overview of different opportunities to get involved in open source geared towards women. I've specifically asked and the girls responded how they first came to join open source. In general they've had a good and welcoming community around them which made it natural to join and thrive.

Now comes the sad part. Instead of welcoming and supporting these girls that they've stood up to talk about their experiences the audience did the opposite. In particular Maya Milusheva from Plushie Games made a very passionate claim against the topic women in tech. It went like this:

  • I am a woman
  • I am a good developer
  • I am a mother
  • I am a CEO of a successful IT company
  • when I hire I want the best people for my company and they are men
  • women simply don't have the required tech skills/level of expertise
  • the whole talk about women in open source/diversity is bullshit
  • girls need to sit down on their asses and read more, code more, etc.

In terms of successfullness I think I can compare to Maya. I also have a small child, which I regularly take to conferences with me (the badges above). I also have an IT company which generates a comparable amount of income. I also want to hire the best employees for any given project I'm working on. Sometimes it's happened that to be a woman, sometimes not. The point here however was not about hiring more women per se. It was about giving opportunities in the communities and letting people grow for themselves.

Yes, she has a point but there's something WRONG in coming to listen to a presenter just to tell them they are full of shit! It's very arrogant shouting around and arguing a point about hiring when in fact the entire presentation was not about hiring! It is totally unacceptable, The NY Times writing about apps you develop and behaving like an asshole at public events at the same time!

I've been there, the crowd telling me I'm full of shit when I've been presenting about new technologies. I've been there being told that my ideas will not work in this or that way, while in fact the very idea of trying and considering a completely different technological approach was what counted. And finally I've been there years later when the same ideas and technologies have become mainstream and the same crowd was now talking about them!

After Maya there was another person who grabbed the microphone and continued to talk nonsense. Unfortunately he didn't state his name and I don't know the guy in person. What he said was along the lines of little boys play with robots, little girls play with dolls. They like it this way and that's why girls don't get involved in the technical field. Also if a girl played with robots she will be called a tomboy and generally have a negative attitude towards her.

It's absolutely clear this guy has no idea what he's talking about. Everyone who has small children around them will agree that they are born with equal mental capacity. It is up to the environment, parents, teachers, etc to shape this capacity in a positive way. I've seen children who taught themselves speaking English from YouTube and children the same age barely speaking Bulgarian. I've seen children who are curious about the world and how it works and children who can't wipe their own noses. It's not because they like it that way, it's because of their parents and the environment they live in.

Finally I'd like to respond to this guy (I was specifically motioned at the conference not to respond) with this

I have a 5 year old girl. She likes robots as much as she likes dolls. She works with Linux and is lucky enough to have one of the two OLPCs laptops in Bulgaria. She plays SuperTux and has already found a bug in it (I've reported it). She's been to several Linux and IT conferences as you can see from the picture above. She likes being taken to hackathons and learning about inspiring stuff that students are doing.

Are you telling me that because we have the wrong idea women can't be good at technology she can't become a successful engineer ? Are you telling me to basically scratch the next 10 years of her life and tell her she can't become what she wants ? Because if you do I say FUCK OFF!

Even I as a parent don't have the power to tell my child what they can do or not do, what they can accomplish or not. My job is to show them the various possibilities that exist and guide and support them along they way they want to go! This is what we as society also need to do for everyone else!

To wrap up I will tell you about a psychological experiment we devised with Jona and Suela. I've proposed to find a male and female student in Tirana and have them pose online as somebody from the opposite sex, fake accounts and all. They've proposed having the same person both act as male or female for the purposes of evening out the tech skills difference. The goal is to see how does the tech community react to their contributions and try to measure how much does their gender being known affect their performance! I hope the girls will find a way to perform this experiment together with the university Psychology department and share the results with us.

Btw I will be visiting OSCAL'17 to check up on that so see you in Albania!

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IT Weekend Highlights

IT Weekend

Last weekend I attended the third IT Weekend. It's like a training camp for athletes but for QA engineers. While during the first week the crowd was more in the junior to mid level range now the crowd was more into the senior level range which made for better talks and discussions. The most interesting sessions for me were On-boarding of New Team Members by Nikola Naidenov and Agile Leadership by Bogoi Bogdanov. Here are some of the highlights that I wrote down:

  • On-boarding of new team members is very important. You need to have a plan for their first 6 months at the company. This plan needs to have clearly defined tasks and expectations;
  • When a person becomes productive for their team/company it means they have been on-boarded successfully;
  • A company provided trainer is a good thing but they tend to focus on broader knowledge, they don't cover team specific domain knowledge;
  • Some companies provide both technical and business trainers for their teams;
  • It is very important to get timely feedback when you are the one providing training. However feedback isn't always easy to get and we don't always receive sincere feedback;
  • If the team is swamped with work tasks you need to provide 10-20% of the time for learning and experimenting with new technologies. IMO this is best done by filing tickets in your bug/task tracking system and prioritizing them together with the rest of the tasks;
  • It is also important to have an individual training plan for each team member and review this on a regular basis;
  • We should strive to use unified terminology and jargon as to not confuse people. IMO it is usually the new hires who are likely to get confused because they are not familiar with the history of the terms used;

In an agile environment we calculate productivity using the formula

Productivity = Effort * Competence * Environment * Motivation^2

There are 3 important factors that drive motivation

  • to have a Purpose
  • to feel Autonomy
  • to be able to achieve Mastery in your skills

It is also important to note that autonomy is not the opposite of alignment as depicted by the image below.

Alignment and autonomy

In agile environment control is a function of trust. To be able to trust people we need to give them autonomy, transparency and short feedback loop!

  • Manage for the normal treat exceptions as exceptional;
  • Failure recovery is more important than failure avoidance;
  • Fail fast means learning fast and improving fast.

Thanks for reading and happy testing!

Photo credit: Rayna Stankova

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Animate & Automate

Recently I've attended a presentation by MentorMate where they talked about testing CSS animations ( video in Bulgarian ). The software under test was an ad tech SDK which provides CSS based animations to mobile apps and games. The content is displayed inside a webview and they had to make sure animations were working correctly on different OS and devices.

Analyzing the content (aka getting to know the domain) they figured out in reality there were about 20 basic movements and transformations. So the problem was reduced to "How do we test these 20 basic movements under various OSes and devices" or "How do we verify that basic CSS transformations are supported under different versions and flavors of the OS"?

Their test bed included hand crafted web pages with each basic movement and then several ones with more complex animations (aka integration testing). The idea was to load these pages under different devices and inspect whether or not the animations were visualized properly.

A test script (aka their testing framework) was constantly recording the coordinates of the elements under test to verify that they were really animated. The idea was to use a sample rate of 20ms and expect at lest 20 different changes to the element under test. Coordinates along with color and gradient were recorded and then returned back and analyzed to report a PASS or FAIL result.

This simplistic framework has limitations of course. It is not currently checking the boundaries of where the elements are rendered on the screen. Thus if everything else works as expected this will be a false positive result. On their slides this can be seen at 23:10.

As a side note the entire effort took about 2 days, including research and preparing the test content.

I really like the back to basics approach here and the simplistic framework that MentorMate came up with. Sure it misses some problems but for that particular case it is good enough, easy and fast to implement.

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The Passionate Doer

Passionate violinist

Two weeks ago I visited Startup Factory Ruse and had the opportunity to attend The Passionate Doer – Lessons Learned where Yana Petrova shared her journey with CoKitchen in the past 2 years. The event name comes from The Passionate Programmer book.

A doer is somebody who acts and strives to make changes. When you jump into something new it looks hard and scary at first. With time the important and difficult tasks begin to look like ordinary ones because you gain the experience required for them.

When you are a start-up company you have a limited amount of time and finance to make a break through. Thus it is important to hire the right people, but Yana argues it is more important to quickly dismiss the people who don't fit into your organization. I quite agree with her and the following paragraphs are centered around this idea.

An interesting point Yana makes is about negative reactions and lack of motivation in employees. When a person is lacking motivation they have troubles making logical connections between various tasks and are not able to see the big picture or how their actions or lack thereof affect everything else in the organization. She thinks these are most likely due to problems in our private lives instead of problems at work and as managers we should seek to understand what triggers these negative effects.

Yana believes fatigue makes us vulnerable to negative thoughts so it is best to make important decisions after you've had a good rest. In similar fashion her way to deal with a non-motivated employee is to give them a short break. Then she asks whether or not the employee is ready to return back to work and invest 100% into the job. If not then both parties say good bye to each other. Yana also says that for most problematic employees she'd seen it hasn't been worth it to bring them back and try to improve them.

I've asked Yana if she had some sort of test to keep track of how well a person performs their job. She didn't quite answer but an indicator for under-performance to her is how busy the rest of the team is. Unwillingness to take corrective action, e.g. explore new ways of doing things, acquire more skills or read particular books which will help improve on areas she'd identified, is also a good indicator that the person will have a tendency to under-perform.

Yana says she wouldn't keep an employee who defines their own boundaries and doesn't want to expand them because that person will not go out of their comfort zone. This leaves everyone else tiptoeing around that employee and having to do the job they can't, which puts more stress on the team.

Same approach we should adopt towards customers as well. Get rid of rude and angry customers so that the work flows with less stress.

Yana has been part of many volunteer efforts and her mistake was that she expected everyone to have the same volunteering spirit that she has. In reality it turned out people had trouble managing their own time or lacking the proper communication skills. Not taking responsibility for your actions and not learning from mistakes are other traits she noticed.

At CoKitchen they aim at pairing completely different people with one another so that everyone is able to learn the most from the other person. This is part of their internal mentorship program.

Another interesting book mentioned by a member of the audience was Drive: The Surprising Truth About What Motivates Us. The book reveals the three elements of true motivation:

  • AUTONOMY - the desire to direct our own lives;
  • MASTERY - the urge to get better and better at something that matters;
  • PURPOSE - the yearning to do what we do in the service of something larger than ourselves.

Sounds like an interesting book (from the point of view of the employer) which is definitely going into my reading list.

Sorry if my notes are a bit terse this time, it's been a busy month. I still hope you learned something new from this post. Thanks for reading!

Image credit: Omar Ismail

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Updated MacBook Air Drivers for RHEL 7.3

Today I have re-build the wifi and backlight drivers for MacBook Air against the upcoming Red Hat Enterprise Linux 7.3 kernel. wl-kmod again needed a small patch before it can be compiled. mba6x_bl has been updated to the latest upstream and compiled without errors. The current RPM versions are


and they seem to work fine for me. Let me know if you have any issues after RHEL 7.3 comes out officially.

PS: The bcwc_pcie driver for the video camera appears to be ready for general use, regardless of some issues. No promises here but I'll try to compile that one as well and provide it in my Macbook Air RHEL 7 repository.

PS2: Sometime after Sept 14th I have probably upgraded my system and now it can't detect external displays if the display is not plugged in during boot. I'm seeing the following

# cat /sys/class/drm/card0-DP-1/enabled

which appears to be the same issue reported on the ArchLinux forum. I'm in a hurry to resolve this and any help is welcome.

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The 4 Basic Communication Styles

4 communication styles

The first GEM Conference in Bulgaria took place on Monday and Tuesday. I missed most of the sessions due to other meetings and tasks but managed to attend a workshop on the topic How to harness the power of influence and communication in entrepreneurship by Plamen Popov and Yassar Markos.

3 Fundamentals for Communication

According to Plamen and Yassar there are 3 key fundamentals for any kind of communication:

  • Willingness to pay the price for this communication to happen;
  • Flexibility because we need to try different approaches until we reach the desired person in a way they can understand what we're saying;
  • Integrity because we always need to be consistent in what we deliver to others so that we always match their expectations.

4 Communication Styles

Then there are 4 basic communication styles based on how formal or informal the communication is and how passive or aggressive it is.

  • Director aka dominant style - they exhibit formal and aggressive communication. Key words for them are results, effectiveness, no small talk, to the point. They dislike wasting their time because they always have something better and more interesting to do. This is why people in this group are the worst listeners. They love conflicts and seek ideas and results.

  • Expresser aka promoting style are dominant/aggressive but informal. They are loud, always speak about themselves, they want public attention and to be unique. They forget details but instead are able to grasp the big picture quite easily. They have lots of energy and passion and love to start new projects and don't complete them.

  • Harmonizer aka supportive style - they exhibit informal and passive communication. They love connections and relationships, they use soft language and look after people and team mates. They don't like conflicts and competitive games. People from this style get impressed when you share personal stories and details with them.

  • Thinker aka analytical style people are formal but non-aggressive. They like to know all the facts and always ask lots of questions because they need to understand the big picture. They need time to understand before they can make a decision. In their lives everything has a particular place. They are prone to postponing tasks until they reach perfection (which they never will).

A person typically has one dominant style and a mix of one or two others. I myself am mostly Director and Expresser aka dominant and promoting with a pinch of Thinker. I mostly lack the Harmonizer traits. However it is more important to know what style the person you are talking to is, not what your personal style is.

When judging the style of others take into account where you stand. A person who is strongly formal and aggressive will view a less formal and mild person as the Expresser or Harmonizer style. However to a 3rd party both of these two persons may appear to be dominated by the Director style.

How to Make a Good Presentation

When presenting to a single person or a small group obviously you have to tailor your presentation according to their communication styles. However when presenting before a large and diverse crowd you need to account for all of them in the following order:

  • Capture the Expresser or promoting style by giving them a promise for something cool and interesting. Because they easily forget details and become distracted you can lose them first.

  • Then capture the Director or dominant style by asserting your authority. State your expertise in the field to establish trust. Also sell them the idea for efficiency because this is the value they need to extract from you.

  • Third comes the Harmonizer or supportive style. They seek open people to connect with. Personal stories and struggles are the best way to engage them.

  • Last comes the Thinker or analytical style. They need to know all the information so you have to give them links and materials for further reading. It is also a good idea to give them the ability to ask you questions later (via email, chat, etc) because they will analyze your ideas and come up with more questions on their own.

I have already started to organize my presentations based on the above 4 key points so hopefully you will see me delivering better talks in the future.

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What I Learned from IT Weekend

IT Weekend

Last week I attended the first IT Weekend in Bulgaria. It's like a training camp for athletes but for QA engineers. There were 20 people attending and the format was very friendly and relaxed. The group had members with various levels of experience and technical skills, also different areas they work in. All presentations are on YouTube. Here's a brief of what happened and what I learned.

I had the honor to present in the first slot and gave a quick introduction to mutation testing. This was my first time giving this talk and I'm not entirely happy with how I've presented it. Also mutation testing is touching a lot on unit tests, programming and source code which in some organizations goes to the devel department. I think mutation testing is harder to understand from people not familiar with it than I initially thought. I'm taking note to improve the way I present this topic to the public.

Yavor Donev gave a good overview of Appium and how to use it on Android. The most important question for me was "Is it possible to utilize the same test suite on Android and iOS, given that the environments are different". With this I mean regardless of how much we try to make the same (native) app on both platforms it will end up differently because the platforms are essentially different. For example there is a different number of physical buttons available.

If we assume that both iOS and Android apps follow the same design and use similar workflow then it should be possible to create a test suite which is platform aware and account for the minor differences. We're also adding another layer of complexity by introducing the requirement that both apps stay in sync with each other and account for the quirks of the foreign platform. Depending on your apps and goals this may not be an easy task!

The one thing I didn't like about Appium is that upstream doesn't care much about version compatibility and they tend to break and change stuff arbitrary between releases. That said if it works, don't update it or otherwise be extremely careful.

I also had a nice chat with Yavor on the topic of career change, learning to program and working with people who have very little coding experience. His approach is to develop a higher level test framework on top of Appium which his team mates can use more easily.

Aneta Petkova's Selenium Grid in Unix Environment is a bit out of my domain. However I took one important lesson: regardless of how great your tools are there are minor details which can make or break your day. In her case these are the physical location of the tests (e.g. which Selenium node runs them) and access to shared resources. Turns out WebDriver doesn't give you this information directly and you need to go through hoops to get it. Her solution was to place the test code on the Grid Hub and provide a shared file system.

The bigger lesson is: whenever you have to design an automated test environment (aka test lab) make sure to evaluate your needs beforehand.

The last talk was a guest appearance by Denitsa Evtimova. She is a QA architect with 16 years of experience and presented the QA strategy at Paysafe group. They have a large monolithic system (legacy code) and have adopted a pyramid style approach to testing. Whenever possible tests are brought down to the lowest level (e.g. unit tests) and not repeated on the higher levels. At the top stand manual testing. Teams are small: 3-4 developers and 2-3 QAs. It is the team responsibility to make sure tests are implemented at the lowest possible level. The process is not strictly enforced and the company relies more on self governance in this aspect. Also everyone on the team can contribute additional tests whenever they see something missing. Test (writing) tasks are all logged in JIRA. They are also small so that everything can be completed in the same day.

The second day was more informal. We did a quick exploratory testing exercise and shared opinions on different test tools. Then the group had a discussion about soft skills and how QA engineers can change the perception of developers about the QA profession (especially in teams where there are many manual testers). The key points are:

  • Criticize the software, not the person, e.g. don't blame the person directly;
  • Communicate with concrete facts and data, not emotions and perceptions;
  • Jokes of the type "how many QA engineers are needed to screw a light bulb" are a problem because they lead to underestimation of the job role;
  • Sometimes it is not quite clear (to others) how the QA role contributes to the development of the product and the organization;
  • For a QA it is important to be able to give a non-biased opinion and observations on what is happening with the product/process;
  • A QA person needs to be very calm. They have to be able to listen to everybody (especially developers) and accept their point of view but at the same time also communicate their own point of view.
  • It is important to sit together with developers and observe the problem, brainstorm and propose possible solutions. This also creates a feedback loop where the developer feels empowered because he's part of the process identifying the problem and proposing the best solution;
  • In agile teams it is a good idea to rotate people between developer and QA positions. This will help them better understand the job of others, acquire new skills and also bring fresh thinking to the team;
  • Quality Assurance is an ungrateful job and only people with very calm and methodical thinking (to follow through and write all possible scenarios) are able to excel in this field. On the other hand developer usually think about the happy path scenarios and strive to make their code work as best as they can;
  • By rotating job roles within the team developers will quickly find out that testing is not their field and gain respect towards their QA peers;
  • US managers have the habit of telling "good job" to everyone, even for small and routine tasks. In Bulgaria (and maybe elsewhere) we're not used to this. Instead we're used of being scolded when we do something wrong. If everything is good then we don't receive any recognition;
  • Using the American "good job" is actually a good thing. Team mates will start performing better over time because they will feel their work is valued and not meaningless, they will feel recognized which will boost morale and productivity.

Thanks for reading and happy testing!

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Peter Sabev on Test Automation

the automation snake chart

Last week Peter Sabev gave his talk "On Reporting Bugs: Errors Made and Lessons learned" for (watch in Bulgarian). At the end of the talk there was a quick question how would he approach automation. I have always approached automation in terms of manpower and skills available within the team while he proposed an approach based on return of investment.

Given that you have a team with strong understanding of the software (code) under test and they have good coding skills then start with the hardest test cases first. This way the team will have lots of hard work upfront and there will be some lead time without visible results. However when the hardest/most complex test cases are already automated you will most likely have covered a big portion of the SUT.

On the contrary, when you start with the easiest test cases first then the team will progress gradually and have enough time to get to grips with the SUT. You are also more likely to see more regressions or bugs missed. With this approach every subsequent automated test will be harder to write and more complex than the previous one. This is a good fit for team who don't have strong experience with test automation and/or are unfamiliar with the product.

Peter proposes a different approach. He plots the test cases as dots, based on how much time they take to execute manually and how much time/how hard is it to automate the particular case. Then you start to move from the lower right corner towards the upper left corner in a weaving motion, like a snake,

His argument is that once you automate the test cases which are not very complex but require lots of time to execute by hand then you free up resources within the team. As you progress up the chart the test cases become harder to automate and yield less return of investment because they don't take some much time to execute manually.

For more information about Peter's approach please read his article.

As you can see from the snake chart the team constantly faces test scenarios jumping up and down on the automation hardness scale. Which also means that you need to have the suitable skills within the team. IMO this is best suited for teams where each member has different degree of experience. I'm also in favor of using the snake chart as a tool to distribute automation tasks within the team.

If you'd like to hear more about Peter's and mine views on manual vs. automated testing be sure to follow We are going to host a discussion on October 18th so stay tuned!

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What I Learned from EuRuKo 2016

EuRuKo 2016

As my frequent readers may know I try to summarize all the conferences and events I go to. This year's EuRuKo inspired me to take a different approach and instead of quickly summarizing the event I will try to highlight what I have learned from it! My intention is to use this as a tool to improve my skills and the work I do. It will probably be a long post so here we go.

Let me say that I don't consider myself a Ruby developer although I do write a small amount of Ruby code. I also don't really consider myself a developer although I have a formal degree in software engineering and do my fair share of open source contributions.

Being different and thinking differently has always been helpful to me in Quality Assurance and this time was no exception. Attending a conference I knew nothing about and meeting with people whose job is totally different than mine turned out to be my greatest experience on the conference circuit this year.

Lesson 1

Get out of the comfort zone, meet new people, exchange ideas and learn! The very fact that I am writing this post not following my usual summary style proves this is working.

Very early during the event I started to notice a recurring theme which grew stronger by the minute. The Ruby community is very open and inclusive to newcomers and they seem to be doing a very good job about on-boarding everyone who wants to learn. I already wrote about Ivan Nemitchenko's experience of organizing remote internships and there are also the Rails Girls local communities, the Rails Girls Summer of Code (didn't know about it) and the various local Ruby communities who pitched their cities to host the next EuRuKo. I really loved this feeling of community. In the broader Linux, Python and QA world I have not seen this being so pronounced.

Lesson 2

Open up (the open source) community even more. Make it easier for newcomers to join! Treat them as human and don't expect them to be like yourself. Do teach and mentor both to help newcomers but also to help yourself become better!

This is mostly on par with my community work but I think I can do better. I will take the time to evaluate what I've been doing in the past and identify areas for improvements. I also encourage my readers and students to send me feedback as well.

I've also learned that junior developers can make meaningful contributions to production grade code when they are given the appropriate set of tasks and guidance. Stephanie Nemeth argued that companies should hire (more) enthusiastic career changers as junior developers because they have very strong motivation for success.

Lesson 3

Re-evaluate how we look at junior developers, especially how we examine and hire them and how we on-board them.

Both lessons 2 and 3 are valid in the open source world and even more so in the corporate world.

I also liked the fact that some of the lightning talks were given by people who had no previous experience in Ruby. @TeamJoda2016 talked about what they did and learn throughout the summer and really cracked the room with their "oh and btw we are looking for a job" as their final slide!

Lesson 4

If you are new/inexperienced at something don't be afraid to try it out. Give it the best you've got and see how it goes. Worst case .... well nothing bad really happens, best case you end up doing the best job in your life. That's also been my personal experience with software testing.

Carina C. Zona's Consequences Of An Insightful Algorithm (old video here) dealt with the ethical responsibilities of us as developers and this is becoming more common with deep learning neural networks.

Lesson 5

We’re able to extract remarkably precise intuitions about an individual. But do we have a right to know what they didn’t consent to share, even when they willingly shared the data that leads us there?

Krissy's The HTT(Pancake) Request made a great analogy of consuming APIs with your customer experience when visiting a restaurant.

Lesson 6

Design APIs (software in general) as if that was a physical product where your customers happiness matters. We see this all the time in our daily jobs and we're guilty of doing it as well. Btw at the moment I'm in the middle of huge refactoring of django-chartit which breaks all backwards compatibility. I guess I will have to re-evaluate my design and approach.

By accident I've made good friends with Alex Georgiev and the folks at Fyber. I liked the fact that at the conference they had couple of people working in QA and we managed to have a nice talk about QA vs developers and the transformation between the two. That also touched on the bigger subject of testers not being able to code and testers not being available for hire.

Lesson 7

Driving people to improve their skills (learn to code, write tests, etc) is possible but needs to come from management, needs clear direction and also a little bit of peer pressure.

After all isn't that what an agile team is supposed to be ?

Now being the able to code, not entirely Ruby ignorant QA guy that I am I was immediately offered several positions in London and Berlin (and no I'm still staying in Sofia). As it turned out good QA engineers with good development skills are in greater demand than developers not only in Sofia but all around the world!

Lesson 8

Fellow QA guys, please do learn to program. Dear developers, please try thinking more like a tester the next time you write code (me included).

Hiring a barista and furnishing your company stand with the best coffee machine you can afford while having an ugly hand written sign saying "MAIN CONFERENCE COFFEE ->" is a marketing stunt that I really love. I'm not sure how well that worked for their hiring but it got them visibility. I'm definitely stealing this one!

Lesson 9

Conference coffee sucks. Provide better one and developers will queue at your stand. To a greater extent - research your target and their needs and provide a product that solves their problem.

What we gave back

indeed Monica it is. Here's the secret sauce

My personal contribution back was telling Yammer and Deliveroo about mutation testing and pointing them to the right tools and videos on the subject. I wish them good luck and happy testing.

NOTE: I will be speaking about mutation testing at several different events in Bulgaria in the next 2 months so make sure to find me if you want to chat.

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What Ivan Learned from Organizing Internships

This is a summary of Ivan Nemytchenko's talk at EuRuKo yesterday (slides here). I'm writing this because that was the best talk both in terms of content and visual presentation I saw at the conference and because it is closely related to my work with HackBulgaria.

The short story is that at some point Ivan was mentoring several junior developers and saw the need to scale this effort so he did a call for interns and got back 60 replies.

What an Intern Gets

  1. Projects in their portfolio
  2. Working experience, including team work
  3. Developing an entire product from idea to production

Ivan wanted to find suitable interns who have basic Ruby on Rails knowledge and who could invest a minimum of 20 hours per week of their time so he devised an aptitude test of 3 parts.

Part 1 is developing basic functionality of the product. Part 2 was adding different user types which require different validation logic, etc. Part 3 was adding "purchasing" logic via external APIs. In Part 3 intentionally there was no code review!

The final result was shit! That was the purpose of the test. The reasoning being that there is no right or wrong way to solve the problems he presented to the interns. Instead he wanted to make them think and decide on a solution. Then feel the pain of their decision. Ivan argues that what made us senior developers are these pains we have experienced at some point in our careers, those fuck-ups that we did in some old project. All of them made us better in our job because we could learn from the mistakes we've made and more importantly understand the consequence of our decisions.

The common mistakes Ivan saw were:

  • Ignoring levels of abstraction;
  • Using too many gems without knowing or understanding their limitations;
  • Gems were treated as the only way to solve a problem. More importantly changing this way was out of the question;
  • Interns didn't know about service objects, well even some experienced developers seem to not know that;
  • Business logic was all around the place;
  • Bad naming all around

The next thing Ivan did was a group hangout code review followed by a short lecture about design patterns, a refactoring session and finally cross code review. At the end the product was delivered as expected.

Following these initial efforts Ivan continued (with even more interns, or the next group of them I think) by asking interns to develop internship automatization, that is a means for the system to distribute tasks based on git commits, tags, etc so it can scale. They've added an admin dashboard and started working on an open source alternative to NewRelic (if I got that correctly). He was also able to enlist 2 more mentors to help him.

Problems Ivan found:

  • Not enough mentors and external projects to work on for all of the interns;
  • Treating a project as not real (e.g. not a real world product) is a mistake;
  • A training project has the same management issues that a real product will have and they need to be resolved in pretty much the same way;
  • There was collective irresponsibility from the group of interns. They didn't do what they said they will do;
  • There were communication issues between the interns and the lack of enough mentors was an obvious problem.
  • There was also lack of motivation.

I'd say these are the typical problems one also sees in almost any teams. It doesn't matter if these are teams of students or teams of developers inside some company.

What a Junior Needs

  • A real project to work on;
  • A business context, a reason why something should be done and why it needs to be done in a particular way;
  • Some visible achievement for their portfolio;
  • Team work experience;
  • Whole cycle development experience.

Ivan thinks that the aptitude test worked great because his interns were able to find good jobs afterwards but he will change a few things. There will be even more tests and he will reject unfit/bad interns. He will also do call for mentors not only for interns. And he wants to turn mentors' experience into tests as well.

I particularly like the "business context" item. IMO even seasoned developers need to have this if they are expected to create a great product for their company. We're not just coders but sometimes companies forget that!

I am also wondering how can I apply a similar aptitude test in my work (both mentoring at HackBulgaria and otherwise).

How about Senior Developers

  • They all have routine tasks;
  • and research tasks;
  • Nice to have features and
  • Low priority features;
  • Side project ideas
  • Missing features in their favorite open source projects

Senior developers' tasks and desires will have to align with what a junior needs in order for the mentorship to work. As senior devs we often make a mistake and expect everyone else to think the same way we do and act as fast as we do. Ideally senior developers want to have multiple clones of ourselves to work with! I myself have been guilty of that and trying to change.

In the context of a for-profit company the above findings should be taken into deep consideration if you are about to have interns.

After the talk I was lucky to talk to Ivan and tell him more about the training sessions at HackBulgaria. I also proposed to him the sponsorship model which he hasn't considered. He then made a counter offer: ask interns for high payment upfront and let them recoup that based on their progress towards the end.

I am really happy to have heard this presentation and being able to talk to Ivan in person. I also have my notes about my "QA and Automation 101" training at HackBulgaria and I now have a better idea how to go about organizing and summarizing them (will try to publish that soon).

Last but not least, Ivan works at GitLab and promised to look at an issue I personally have so here it is GitLab #7953 :).

Related reading

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Questers Beer'n'Code Day 2.0

Last weekend I've visited Questers Beer'n'Code Day which was an open air mini-conference held at the terrace of their office. As to organization the only drawback was the summer sun which made it impossible to see anything on the screen. Most speakers were OK with that although they wanted to show some code examples.

I have recorded all talks and they are available in my TECH TALKS YouTube play list. You can also hear me asking some questions from behind the camera. All of the talks are in Bulgarian though, so sorry for my English speaking readers.

The afternoon started with Lidiya Georgieva and her talk about clean code and code smells. I find the topic particularly interesting but she didn't go into more details. She said she had used SonarCube but couldn't recommend any other tools, except for the standard lint style ones. I have been using for all Python based code I've been working on recently and I think it is great.

Another talk I found interesting was by my fellow QA Petar Sabev on reporting bugs. It was more of an entry level talk, but still very informative for both less experienced QAs and other technical folks so I definitely recommend it.

The last one, and most interesting, was Bogoi Bogdanov with Scaling Agile. Despite the name he covered some basics about Agile and what it actually is. Afterwards we've stayed and talked for a good 2 hours more. I definitely would like to hear more from him in the future.

A big thanks to Questers for hosting this event and allowing me to record it. Happy watching.

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Python 2 vs. Python 3 List Sort Causes Bugs

Can sorting a list of values crash your software? Apparently it can and is another example of my Hello World Bugs. Python 3 has simplified the rules for ordering comparisons which changes the behavior of sorting lists when their contents are dictionaries. For example:

Python 2.7.5 (default, Oct 11 2015, 17:47:16) 
[GCC 4.8.3 20140911 (Red Hat 4.8.3-9)] on linux2
>>> [{'a':1}, {'b':2}] < [{'a':1}, {'b':2, 'c':3}]
Python 3.5.1 (default, Apr 27 2016, 04:21:56) 
[GCC 4.8.3 20140911 (Red Hat 4.8.3-9)] on linux
>>> [{'a':1}, {'b':2}] < [{'a':1}, {'b':2, 'c':3}]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unorderable types: dict() < dict()

The problem is that the second elements in both lists have different keys and Python doesn't know how to compare them. In earlier Python versions this has been special cased as described here by Ned Batchelder (the author of Python's coverage tool) but in Python 3 dictionaries have no natural sort order.

In the case of django-chartit (of which I'm now the official maintainer) this bug triggers when you want to plot data from multiple sources (models) on the same chart. In this case the fields coming from each data series are different and the above error is triggered.

I have worked around this in commit 9d9033e by simply disabling an iterator sort but this is sub-optimal and I'm not quite certain what the side effect might be. I suspect you may end up with a chart where the order of values on the X axis isn't the same for the different models, e.g. one graph plotting the data in ascending order the other one in descending.

The trouble also comes from the fact that we're sorting an iterator (a list of fields) by telling Python to use a list of dicts to determine the sort order. In this arrangement there is no way to tell Python how we want to compare our dicts. The only solution I can think about is creating a custom class and implementing a custom __cmp__() method for this data structure!

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