Saturday, May 23, 2020

How to Test Anything

This post is a prettied-up version of the notes I made in advance of my talk, How To Test Anything, at the OnlineTestConf 2020 this week. Here's the abstract:

Sometimes you’re asked to start testing in a context that is not ideal: you’ve only just joined the project, the test environment is broken, the product is migrating to a new stack, the developer has left, no-one seems quite sure what’s being done or why, and there is not much time. 

Knowing where to begin and what to focus on can be difficult and so in this talk I’ll describe how I try to meet that challenge.

I’ll share a definition of testing which helps me to navigate uncertainty across contexts and decide on a starting point. I’ll catalogue tools that I use regularly such as conversation, modelling, and drawing; the rule of three, heuristics, and background knowledge; mission-setting, hypothesis generation, and comparison. I’ll show how they’ve helped me in my testing, and how I iterate over different approaches regularly to focus my testing.

The takeaways from this talk will be a distillation of hard-won, hands-on experience that has given me
    • an expansive, iterative view of testing
    • a comprehensive catalogue of testing tools
    • the confidence to start testing anything from anywhere

How to test anything, then. The title felt gooooood when I proposed it after being invited to speak at the conference, but not so much when I came to write the talk! 

I'm very much not an egotist and the message I want to convey here is not that you should test in the patented, certified, Thomas Way. Rather, I think that there are useful approaches to testing independent of the application and the context, and I want to share the ones that I use and how I use them.

Let's start with a thought experiment.

You are watching a robot and me — a tester —  interacting with the same system. Our actions are, to the extent that you can tell, identical and the system is in the same state at each point in the sequence of actions for both of us. The machine and me performed the same actions on the same system with the same visible outcomes.

If I told you I was testing, would you feel comfortable saying that the robot was testing too? I’d have a hard time saying that it was. Harry Collins and Martin Kusch, in The Shape of Actions, reckon that:

Automation of some task becomes tractable at the point where we become indifferent to the details of it.

I'm not bashing automation — I’m a regular user of automation as a tool in testing — but whatever complexity you put into your robot, my instinct is that it's not going to be as flexible as a human could be when encountering a given situation, particularly an unforeseen one.  Automation naturally can’t consider all the details, filtering out only the ones that seem interesting given knowledge of the context in the way that a human can.

For me, testing requires there to be intent, deliberate actions, agency, and responsiveness to observation on the part of the tester. I also have a strong idea of what is required for something to be tested.

In this post, I’ll describe what testing is for me, I’ll list some of the testing tools that I think are useful across contexts, and I'll give a simple heuristic for starting testing when you're stuck.

So what is testing? Arborosa has collected many definitions dating back to the 1950s and I spent some time a couple of years ago looking over them and reflecting on how I like to work, before coming up with a definition that works for me:

Boom! It’s a mouthful, but I can unpack it.

Incongruity: Oxford Dictionaries define this as "not in harmony or keeping with the surroundings". I interpret lack of harmony as a potential problem and lack of keeping as an actual problem, and those two interpretations are interesting and useful in testing.

Pursuit: Again, there are two senses that capture important aspects of testing for me. You can pursue something that you don't know is there and that you may never find, like a dream. Or you can pursue the solution to a problem that you know you have, that's right in front of you. 

Relevant: if this work doesn't matter to anyone, why are we doing it? Whoever that is can help us to understand whether any incongruities we identify are valuable to them, relevant to the project.

Which is great but, so what? Well, I can use it as a yardstick to gauge my activity against: I might want to be testing but realise I’m doing something else; I might be happy to do choose to do stuff that needs doing but isn’t testing.

Testing doesn't proceed in a linear fashion for me, either. I will typically choose to do something, get data from it, review that data, and then decide what to do next in a cycle.

To help me to test, I use tools. I've listed some of them here:

And what is a tool? For me it's simply a thing used to help perform a job and I've thought a lot about tools. (Take Your Pick: Part 1, Part 2, Part 3, Part 4.)

I have a toolbox that I carry with me, and I've taken care to become familiar with the tools so that I can reach for a tool that looks appropriate when I need it. My shed is organised the same way:

I like also to have a cache of stuff that isn't tools I'm familiar with and skilled at using, but which might come in handy, like this box of bits I've emptied out onto my bench. Sometimes the shape of the problem in front of you doesn't fit the shape of any of your tools, but there may be something in the box that can be offered up to it.

Perhaps I've used Selenium and have a grasp of its workings, its pros, and its cons. That's a tool and it's on my shelf. Let's say I've seen a webinar about Cypress and talked to a couple of team members who have experimented with it. That's in my box. If I see a problem that is similar to one I might use Selenium for, but isn't quite the right shape, I might reach for Cypress.

It's also important to practice with your tools. Learn when they apply well and when they don't. This tunes your intuition about when they'll be helpful or when they're actively working against your need. It also helps you to keep up to date and skilled with them. 

Here's a few of the tools I use all the time:
The best testers will be layering their activities. They’ll have a mission in mind but will be consciously trying to approach it in a way that gives them the chance to uncover other things. For example, they might be able to think of three ways to check some functionality and they’ll choose the one that exposes them to a bit of the product they haven’t seen much of, or has recently changed; maybe they’ll see a usability issue, or a performance problem that way.

The skilled tester might leave environments around when they’re finished with them so that some other later testing can be done in a dirty environment not in something that has been set up just for the test. Sometimes just coming back to a system that has been running by itself for a few days can show a problem.

I urge you to do this kind of conscious, intentful testing! Of course, a prerequisite for that  is starting and sometimes it's not easy.

Yes, it can be challenging because you don't want to make a mistake, to look foolish in front of new team mates, or set the project off down the wrong path. But I have a helpful heuristic:

You don’t necessarily need to wait for the requirements, or stability, or even a build of the application under test to start testing. Begin where you are!

Some factors that can help you to understand where you are:
  • constraints: budget, resources, time, ...
  • context: what is this product for, who is it for, what do they want to do, ...
  • value: who are your stakeholders, what are they looking for from you, ...
Choosing what to do next to deliver value to the project is setting your mission and I like to frame my missions using this slight variant of Elisabeth Hendrickson's charter template:

On a recent project I joined, I thought that the biggest challenge to customer and business value was (the way I saw it) disagreement amongst three stakeholders. In this case, I wrote a 2-page product description that crystallised what I thought we were building and importantly what I thought we were not building. When this was put in front of the team, and the stakeholders, we were able to have a conversation that squeezed out the differences.

You might reasonably ask whether I was testing. I think that in the main I was, yes. I was pursuing relevant incongruity.

I said three key things were needed for testing but in fact there's a fourth: something to test. I realised while I was writing the talk that I've encapsulated pretty much everything I've said so far in a page on my team's wiki. I pair with someone from my team every week. As a manager, ad hoc pairing is tricky for me to set up, but a recurring calendar appointment works. So I came up with some guidelines to help others help me to be involved:

I like to set the mission so that we are intentional and I like to reflect so that we have a chance to learn and change, but the key thing here is that I'm happy to start anywhere on anything completely from cold. I'm confident that I can bring something to the party wherever, whenever, and whatever that party is.  

So that's how I test anything: I have an idea what testing means for me, I find and practice with tools that help me to achieve it, and I'm not afraid to start from where I am and iterate.

Here's the video and full slides:


  1. Thank you James for your blog post, it was insightful. I am also to have found Elisabeth Hendrickson's charter template through your blog.

    1. Thanks, Trevor. I hope you find the template as useful as I have over the years.