February 8, 2019
10 Years of Codemanship2019 marks the 10th anniversary since I started my training an coaching company for developers, Codemanship.
Since 2009, I've trained more than 3,000 developers on public coourses and client-site workshops, and hundreds of thousands more have downloaded the free tutorials, watched the free screencasts and read the TDD course book online.
I've been lucky enough to work with some great clients, including the BBC, Sage, UBS, Elsevier, John Lewis, Samsung, ASOS, Ordnance Survey and many more great companies, and worked all over the UK, as well as in Ireland, France, Germany, Spain, Portugal, the Netherlands, Norway, Sweden, Finland, Romania and Poland.
I'm also proud to have started the original Software Craftsmanship conference that inspired many more, to have - with your help - raised tens of thousands of pounds for Bletchley Park, and for maths and coding clubs. I've produced a sell-out West End comedy show, and even collaborated on an album that made it into Amazon's dance top 20!
In this time of rapid change and uncertainty, who knows what the next 10 years of Codemanship may bring. One thing's for sure: it won't be dull!
To celebrate 10 years of Codemanship, I'm offering 10 exclusive 1-day code craft training workshops to be run on client sites.
You can choose from:
- Software Design Principles
- Unit Testing
And any one of 10 Tuesdays or Thursdays coming up between now and Brexit (if you're in the EU, get 'em while you can!!!)
Just pick your date, and choose your course, whip out the company credit card, and Bob's your uncle. (Payment by invoice is also available.)
Each 1-day workshop costs £1,795 for up to 20 people - that's as little as £90 per person. (Normal price for a 1-day code craft workshop is £3,995.)
January 9, 2019
Team Craft - New Codemanship Workshop for 2019I'm delighted to announce the launch of a new Codemanship workshop for 2019. Team Craft is a one-day workshop for 6-12 people that's stretches your skills in collaborative design and continuous delivery.
It's the product of 10 years running team exercises as part of Codemanship training workshops, as well as at conferences and meet-ups around the world. These experiences have been consolidated and refined into an action-packed day that will turbo-charge the Team Fu of new and established teams alike.
It promotes technical team skills like:
- Collaborative Design
- Mob Programming
- Trunk-based Development
- Continuous Integration and Continuous Delivery
Team Craft is a completely hands-on workshop that reaches the parts other workshops don't.
Over the course of the day, participants will design and deliver a working solution to a realistic real-world problem as a team.
From a standing start, they will:
- Break down the requirements
- Assign work to individuals and/or pairs
- Choose the technology stack
- Set up version control
- Set up a CI server to build and test the solution as it takes shape
- Agree on a high-level design and establish the interfaces and contracts between components/services
- Test-drive the implementation of the components
- Demonstrate a working end product to their "customer" (the trainer)
The emphasis is on learning by doing, with a 45-minute introduction with key tips on how to succeed as a team, and ending with a 45-minute retrospective where we will draw out lessons learned in the 5-hour practical exercise.
To find out more, visit http://codemanship.co.uk/teamcraft.html
December 17, 2018
The Santa Present Delivery Route Optimisation KataThe holiday season is upon us, and one of the upsides of running a training company is that - while your clients run themselves ragged trying to hit seasonal deadlines - you get to relax and enjoy the inverse level of busyness.
This gives me time to imagine a fun but challenging new code kata: The Santa Present Delivery Route Optimisation Kata. It's a TDD challenge, but also a Third-Generation Testing challenge, as you'll see.
Santa has to visit the ten biggest cities in the US, listed here with their populations and coordinates:
Santa's sleigh travels at a constant speed of 3,000 km per hour between cities, and the delivery of each present takes him 0.001 seconds (i.e., he can deliver 3.6 million presents an hour in the same city.)
He has between midnight and 6 a.m. to deliver as many presents in the US as possible. He can start in any of the 10 cities.
Using this information, create a program that will efficiently calculate the route that will deliver the most amount of presents in those 6 hours.
Using parameterised tests, check your program's solution against the result of an exhaustive search of all possible routes between the 10 cities (assuming each city is visited only once).
Now generalise your solution for the following variables:
1. The list of cities
2. The amount of available delivery time
3. The speed of Santa's sleigh
4. The number of concurrent Santas
December 2, 2018
Architecture: The Belated Return of Big Picture ThinkingA question that's been stalking me is "When does architecture happen in TDD?"
I see a lot of code (a LOT of code) and if there's a trend I've noticed in recent years it's an increasing lack of - what's the word I'm looking for? - rationality in software designs as they grow.
When I watch dev teams produce working software (well, the ones who do produce software that works, at least), I find myself focusing more and more on when the design decisions get made.
In TDD, we can make design decisions during four distinct phases of the red-green-refactor cycle:
1. Planning - decisions we make before we write any code (e.g., a rough sequence diagram that realises a customer test scenario)
2. Specifying- decisions we make while we're writing a failing test (e.g., calling a function to do what you need done for the test, and then declaring it in the solution code)
3. Implementing - decisions we make when we're writing the code to pass the test (e.g., using a loop to search through a list)
4. Refactoring - decisions we make after we've passed the test according to our set of organising principles (e.g., consolidating duplicate code into a reusable method)
If you're a fan of Continuous Delivery like me, then a central goal of the way you write software is that it should be (almost) always shippable. Since 2 and 3 imply not-working code, that suggests we'd spend as little time as possible thinking about design while we're specifying and implementing. While the tests are green (1 and 4), we can consider design at our leisure.
I can break down refactoring even further, into:
4a. Thinking about refactoring
4b. Performing refactorings
Again, if your goal is always-shippable code, you'd spend as little time as possible executing each refactoring.
Put more bluntly, we should be applying the least thought into design while we're editing code.
(In my training workshops, I talk about Little Red Riding Hood and the advice her mother gave her to stay on the path and not wander off into the deep dark forest, where dangers like Big Bad Wolves lurk. Think of working code as the path, and not-working code as the deep dark forest. I encourage developers to always keep at least one foot on the path. When they step off to edit code, they need to step straight back on as quickly as possible.)
Personally - and I've roughly measured this - I make about two-thirds of design decisions during refactoring. That is, roughly 60-70% of the "things" in my code - classes, methods, fields, variables, interfaces etc - appear during refactoring:
* Extracting methods, constants and such to more clearly document what code does
* Extracting methods and classes to consolidate duplicate code
* Extracting classes to eliminate Primitive Obsession (e.g., IF statements that hinge on what is obviously an object identity represented by a literal vaue)
* Extracting and moving methods to eliminate Feature Envy in blocks of code and expressions
* Extracting methods and classes to split up units of code that have > 1 reason to change
* Exctracting methods to decompose complex conditionals
* Extracting client-specific interfaces
* Introducing parameters to make dependencies swappable
And so on and so on.
By this process, my code tends to grow and divide like cells with each new test. A complex order emerges from simple organising principles about readabililty, complexity, duplication and dependencies being applied iteratively over and over again. (This is perfectly illustrated in Joshua Kerievky's Refactoring to Patterns.)
I think of red-green-refactor as the inner loop of software architecture. And lots of developers do this. (Although, let's be honest, too many devs skimp on the refactoring.)
But there's architecture at higher levels of code organisation, too: components, services, systems, systems of systems. And they, too, have their organising principles and patterns, and need their outer feedback loops.
This is where I see a lot of teams falling short. Too little attention is paid to the emerging bigger picture. Few teams, for example, routinely visualise their components and the dependencies between them. Few teams regularly collaborate with other teams on managing the overall architecture. Few devs have a clear perspective on where their work fits in the grand scheme of things.
Buildings need carpentry and plumbing. Roads need tarmaccing. Sewers need digging. Power lines need routing.
But towns need planning. Someone needs to keep an eye on how the buildings and the roads and the sewers and the power lines fit together into a coherent whole that serves the people who live and work there.
Now, I come from a Big ArchitectureTM background. And, for all the badness that we wrought in the pre-XP days, one upside is that I'm a bit more Big Picture-aware than a lot of younger developers seem to be these days.
After focusing almost exclusively on the inner loop of software architecture for the last decade, starting in 2019 I'm going to be trying to help teams build a bit of Big Picture awareness and bring more emphasis on the outer feedback loops and associated principles, patterns and techniques.
The goal here is not to bring back the bad old days, or to ressurect the role of the Big Architect. And it's definitely not to try to reanimate the corpse of Big Design Up-Front.
This is simply about nurturing some Big Picture awareness among developers and hopefully reincorporating the outer feedback loops into today's methodologies, which we misguidedly threw out with the bathwater during the Agile Purges.
And, yes, there may even be a bit of UML. But just enough, mind you.
October 12, 2018
TDD Training - Part I (Classic TDD), London, Sat Dec 1stMy flagship Codemanship TDD training course returns in a series of 3 standalone Saturday workshops aimed at self-funding learners.
It's the exact same highly popular training we've delivered to more than 2,000 developers since 2009, with 100% hands-on learning reinforced by our jam-packed 200-page TDD course book.
Part 1 is on Saturday Dec 1st in central London, and it's amazingly good value at just £99.
Part I goes in-depth on "classic" TDD, the super-important refactoring discipline, and software design principles that you can apply to your code as it grows and evolves to keep it easy to change so you can maintain the pace of development.
- Why do TDD?
- An introduction to TDD
- Red, Green, Refactor
- The Golden Rule
- Working backwards from assertions
- Testing your tests
- One reason to fail
- Writing self-explanatory tests
- Speaking the customer's language
- Triangulating designs
- The Refactoring discipline
- Software Design Principles
- Simple Design
- Tell, Don’t Ask
The average price of a public 1-day dev training course, per person, is around £600-800. This is fine if your company is picking up the tab.
But we've learned over the years that many devs get no training paid for by their employer, so we appreciate that many of you are self-funding your professional development. Our Saturday workshops are priced to be accessible to professional developers.
In return, developers who've attended our weekend workshops have recommended us to employers and colleagues, and most of the full-price client-site training and coaching we do comes via these referrals.
Please be advised that we do not allow corporate bookings on our workshops for self-funders. Group bookings are limited to a maximum of 4 people. If you would like TDD training for your team(s), please contact me at firstname.lastname@example.org to discuss on-site training.
Find out more at the Eventbrite course page
October 6, 2018
Be The Code You Want To See In The WorldIt's no big secret that I'm very much from the "Just Do It" school of thought on how to apply good practices to software development. I meet teams all the time who complain that they've been forbidden to do, say, TDD by their managers. My answer is always "Next time, don't ask".
After 25 years doing this for a living, much of that devoted to mentoring teams in the developer arts , I've learned two important lessons:
1. It's very difficult to change someone's mind once it's made up. I wasted a lot of time "selling" the benefits of technical practices like unit testing and refactoring to people for whom no amount of evidence or logic was ever going to make them try it. It's one of the reasons I don't do much conference speaking these days.
2. The best strategies rely on things within our control. Indeed, strategies that rely on things beyond our control aren't really strategies at all. They're just wishful thinking.
The upshot of all this is an approach to working that has two core tenets:
1. Don't seek permission
2. Do what you can do
Easy to say, right? It does imply that, as a professional, you have control over how you work.
Here's the thing: as a professional, you have control over how you work. It's not so much a matter of getting that control, as recognising that - in reality - because you're the one writing the code, you already have that control. Your boss is very welcome to write the code themselves if they want it done their way
Of course, with great power comes great responsibility. You want control? Take control. But be sure to be acting in the best interests of your customer and other stakeholders, including the other developers on your team. Code is something you inflict on people. Do it with kindness.
And so there you have it. A mini philosophy. Don't rant and rave about how code should be done. Just do it. Be the code you want to see in the world.
Plenty of developers talk a good game, but their software tells a different story. It's often the case that the great and worthy and noble ideas you see presented in books and at conferences bear little resemblence to how their proponents really work. I've been learning, through Codemanship, that it's more effective to show teams what you do. Talk is cheap. That's why my flagship TDD workshop doesn't have any slides. Every idea is illustrated with real code, every practice is demonstrated right in front of you.
And there isn't a single practice in any Codemanship course I haven't applied many times on real software for real businesses. It's all real, and it all really works in the real world.
What typically prevents teams from applying them isn't their practicality, or how difficult they are to learn. (Although don't underestimate the learning curves.) The obstacles are normally whether they have the will to give it a proper try, and tied up in that, whether they're allowed to try it.
My advice is simple: learn to do it under the radar, in the background, under the bedsheets with a torch, and then the decision to apply it on real software in real teams for real customers will be entirely yours.
October 1, 2018
50% Off Codemanship Training for Start-ups and CharitiesOne of the most fun aspects of running a dev training company is watching start-ups I helped a few years ago go from strength to strength.
The best part is seeing how some customers are transforming their markets (I don't use the "d" word), and reaping the long-term benefits of being able to better sustain the pace of innovation through good code craft.
I want to do more to help new businesses, so I've decided that - as of today - start-ups less than 5 years old, with less than 50 employees, will be able to buy Codemanship code craft training half-price.
I'm also extending that offer to non-profits. Registered charities will also be able to buy Codemanship training for just 50% of the normal price.
September 28, 2018
Micro-cycles & Developing Your Inner Egg TimerWhen I'm coaching developers in TDD and refactoring, I find it important to stress the benefits of keeping one foot on the path of working code at all times.
I talk about Little Red Riding Hood, and how she was warned not to stray off the path into the deep dark forest. Bad things happen in the deep dark forest. Similarly, I warn devs to stay on that path of code that works - code that's shippable - and not go wandering off into the deep dark forest of code that's broken.
Of course, in practice, we can't change code without breaking it. So the real skill is in learning how to make the changes we need to make by briefly stepping off the path and stepping straight back on again.
This requires developers to build a kind of internal egg timer that nudges them when they haven't seen their tests pass for too long.
An exercise I've used to develop my internal egg timer uses a real egg timer (or the timer on my smartphone). When I'm mindfully practicing refactoring, for example, I'll set a timer to countdown for 60 seconds, and start it the moment I edit any code.
The moment a source file goes "dirty" - no longer compiles or no longer passes the tests - the countdown starts. I have to get back to passing tests before the sands run out (or the alarm goes off).
I'll do that for maybe 10-15 minutes, then I'll drop the countdown to 50 seconds and do another 10-15 minutes. Then 40 seconds. Then 30. Always trying, as best I can, to get what I need to do done and get back to passing tests before the countdown ends.
I did this every day for about 45-60 minutes for several months, and what I found at the end was that I'd grown a sort of internal countdown. Now, when I haven't seen the tests pass for a few minutes, I get a little knot in my stomach. It makes me genuinely uncomfortable.
I do a similar exercise with TDD, but the countdowns apply the moment I have a failing test. I have 60 seconds to make the test pass. Then 50. Then 40. Then 30. This encourages me to take smaller steps, in tighter micro-cycles.
If my test requires me to take too big a leap, I have to scale back or break it down to simpler steps to get me where I want to go.
The skill is in making progress with one foot firmly on the path of working code at all times. Your inner egg timer is the key.
September 25, 2018
Third-Generation Testing - Øredev 2018, Malmö, November 22ndIf you're planning on coming to Øredev in Sweden this November, I'm running a brand new training workshop on the final day about Third-Generation Software Testing.
First-generation testing was manual: running the program and clicking the buttons ourselves. We quickly learned that this was slow and often patchy, creating a severe bottleneck in development cycles.
Second-generation testing removed that bottleneck by writing code to test our code.
But what about the tests we didn't think of?
Exploratory testing brought us back to a manual process of exploring what else might be possible - what combinations of inputs, user actions and pathways - using the code we delivered, outside of the behaviours encoded in our automated tests.
Manual exploratory testing suffers from the same setbacks as any kind of manual testing, though. It's slow, and can miss heaps of cases in complex logic.
Third-generation testing automates the generation of the test cases themselves, enabling us to explore much wider state spaces than a manual process could ever hope to achieve. With a little extra test code, and a bit of ingenuity, you can explore thousands, tens of thousands, hundreds of thousands and even millions of extra test cases - combinations, paths, random inputs and ranges - using tools you already know.
In this workshop, we'll explore some simple techniques for adapting and reusing our existing unit tests to exhaustively test our critical code. We'll also look at techniques for identifying what code might need us to go further, and how we can use Cloud technology to execute millions of extra tests in minutes.
You can find out more and book your place at http://oredev.org/2018/sessions/third-generation-software-testing
September 24, 2018
Why I Throw Away (Most Of) My Customer TestsThere was a period about a decade ago, when BDD frameworks were all new and shiny, when some dev teams experimented with relying entirely on their customer tests. This predictably led to some very slow-running test suites, and an upside-down test pyramid.
It's very important to build a majority of fast-running automated tests to maintain the pace of development. Upside-down test pyramids become a severe bottleneck, slowing down the "metabolism" of delivery.
But it is good to work from precise, executable specifications, too. So I still recommend teams work with their customers to build a shared understanding of what is to be delivered using tools like Cucumber and Fitnesse.
What happens to these customer tests after the software's delivered, though? We've invested time and effort in agreeing them and then automating them. So we shoud keep them, right?
Well, not necessarily. Builders invest a lot of time and effort into erecting scaffolding, but after the house is built, the scaffolding comes down.
The process of test-driving an internal design with fast-running unit tests - by which I mean tests that ask one question and don't involve external dependencies - tends to leave us with the vast majority of our logic tested at that level. That's the base of our testing pyramid, and as it should be.
So I now have customer tests and unit tests asking the same questions. One of them is surplus to requirements for regression testing, and it makes most sense to retain the fastest tests and discard the slowest.
I keep a cherrypicking of customer tests just to check that everything's wired together right in my internal design - maybe a few dozen key happy paths. The rest get archived and quite possibly never run again, or certainly not an a frequent basis. They aren't maintained, because those features or changes have been delivered. Move on.