investigating software

Mostly Harmless, I've talked and written about randomisation as a technique in software testing several times over the last few years. It's great to see people's eyes light up when they grok the concept and its potential.  The idea that they can create random test data on the fly and pour this into the app step back and see what happens is exciting to people looking to find new blockers on their apps path to reliability. But it's not long before a cloud appears in their sunny demeanour and they start to conceive of the possible pitfalls. Here are a few tips on how to avert the common apparent blockers. (Part 1) A good motto for software testing, as well as pan-galactic hitchhiking. Problem: I've created loads of random numbers as input data, but how will I know the answer the software returns, is correct? - Do I have to re-implement the whole app logic in my test code? Do you remember going to the fun-fair as a kid? Or maybe you recall tak

How did you find that bug? - They asked with a sort of puzzled " he dun't thunk like uz " look on their faces. An expression that suggested they were unsure whether to commend the discovery or gather their pitchforks and organise a well overdue witch burning. Likewise, I now knew why they needed me. The team members were genuinely hard working people trying to build something new and exciting. But they lacked one thing, someone exploring & asking questions - trying to find out new things about their application. Exploring is literally a step into the unknown, and that can be uncomfortable for those not experienced in how to do it well. Exploring is literally a step into the unknown. So how did I find that bug? It's easy to tell a story of how I tried that particular input value because... Paragraph 3 of v4.6 of the requirements document stated that the user shall indeed on occasion X given input Y in Chrome v62 do... Or spout some other overly verb

The release shipped. For a while, the team felt good. The work was done, the team had achieved something, and that was rewarding.  Unfortunately for the team, it wasn't long before a problem was found. The Product Owner wasn't happy and had asked was going on down there in the galley, do we need new coders? Better ones? Hipster coders? The release shipped... After an investigation, some blushes, raised eyebrows and a couple of "Oh... Yeeeah's" they found the cause. A confusion had collided with a bodge, and the result was a mess. Should they write an automated - test for this problem?  An embarrassing mistake or a misstep can make us feel we have to do something . An action greater than a fix is needed. A penitance needs to be performed, to redeem ourselves, to make us right again. Sometimes the penitence is best spent adding a test for that issue. Especially if writing that test has a low cost, the frequency of the problem occurring is high or

There is a pattern I see with many clients, often enough that I sought out a word to describe it: Manumation, A sort of well-meaning automation that usually requires frequent, extensive and expensive intervention to keep it 'working'. You have probably seen it, the build server that needs a prod and a restart 'when things get a bit busy'. Or a deployment tool that, 'gets confused' and a 'test suite' that just needs another run or three. The cause can be any number of the usual suspects - a corporate standard tool warped 5 ways to make it fit what your team needs. A one-off script 'that manager' decided was an investment and needed to be re-used... A well-intended attempt to 'automate all the things' that achieved the opposite. They result in a manually intensive - automated process, where your team is like a character in the movie Metropolis, fighting with levers all day, just to keep the lights on upstairs. Manual-automation, manu

Many, Many years ago I worked at a startup called Lastminute.com (a European online travel company, back when a travel company didn't  have to be online). For a while, I worked in what would now be described as a 'DevOps' team. A group of technical people with both programming and operational skills. I was in a hybrid development/operations role, where I spent my time investigating and remedying production issues using my development, investigative and still nascent testing skills. It was a hectic job working long hours away from home. Finding myself overloaded with work, I quickly learned to be a little ruthless with my time when trying to figure out what was broken and what needed to be fixed. One skill I picked up, was being able to distinguish whether I was researching a bug  or trying to find a new bug. When researching , I would be changing one thing or removing something (etc) and seeing if that made the issue better or worse. When looking for bugs , I

A while back, I sat in on a planning meeting. Many planning meetings slide awkwardly into a sort of ad-hoc technical analysis discussion, and this was no exception. With a little prompting, the team started to draw up what they wanted to build on a whiteboard. The picture spoke its thousand words, and I could feel that the team now understood what needed to be done. The right questions were being asked, and initial development guesstimates were approaching common sense levels. The discussion came around to testing, skipping over how they might test the feature, the team focused immediately on how long testing would take. When probed as to how the testing would be performed? How we might find out what the team did wrong? Confused faces stared back at me. During our ensuing chat, I realised that they had been using BDD scenarios [only] as a metric of what testing needs to be done and when they are ready to ship. (Now I knew why I was hired to help) There is nothing wrong with c

Is your car German or Japanese? Are your chocolates from Belgium? And your wine, which country might that be from? There's a good chance you know the answer to some of those questions. Our culture places value on provenance. That is, we care where our possessions originate. It's something we tend to notice. Warning label? Furthermore, we ascribe, often without our notice, characteristics to things because of their provenance. For example, that's a Japanese radio - its reliable but not cheap, etc. I often do this un-empirically, without measurement or examination. (that's a flaw) For software testing, our automatic identification of provenance can be both a useful tool and a distraction.  Noticing where or from whom a feature originated can be enlightening. You may learn over time that a particular team or person tends to implement certain things well, and others things not so well. This has a tendency to help me to find some bugs relatively easily w