June 21, 2018

Learn TDD with Codemanship

Adopting TDD - The Codemanship Roadmap

I've been doing Test-Driven Development for 20 years, and helping dev teams to do it for almost as long. Over that time I've seen thousands of developers and hundreds of teams try to adopt this crucial enabling practice. So I've built a pretty clear picture of what works and what doesn't when you're adopting TDD.

TDD has a steep learning curve. It fundamentally changes the way you approach code, putting the "what" before the "how" and making us work backwards from the question. The most experienced developers, with years of test-after, find it especially difficult to rewrite their internal code to make it comfortable. It's like learning to write with your other hand.

I've seen teams charge at the edifice of this learning curve, trying to test-drive everything from Day #1. That rarely works. Productivity nosedives, and TDD gets jettisoned at the next urgent deadline.

The way to climb this mountain is to ascend via a much shallower route, with a more gentle and realistic gradient. You will most probably not be test-driving all your code in the first week. Or the first month. typically, I find it takes 4-6 months for teams to get the hang of TDD, with regular practice.

So, I have a recommended Codemanship Route To TDD which has worked for many individuals and teams over the last decade.

Week #1: For teams, an orientaton in TDD is a really good idea. It kickstarts the process, and gets everyone talking about TDD in practical detail. My 3-day TDD workshop is designed specifically with this in mind. It shortcuts a lot of conversations, clears up a bunch of misconceptions, and puts a rocket under the team's ambitions to succeed with TDD.

Week #2-#6: Find a couple of hours a week, or 20 minutes a day, to do simple TDD "katas", and focus on the basic Red-Green-Refactor cycle, doing as many micro-iterations as you can to reinforce the habits

Week #7-#11: Progress onto TDD-ing real code for 1 day a week. This could be production code you're working on, or a side project. The goal for that day is to focus on doing it right. The other 4 days of the week, you can focus on getting stuff done. So, overall, your productivity maybe only dips a bit each week. As you gain confidence, widen this "doing it right" time.

Week #12-#16: By this time, you should find TDD more comfortable, and don't struggle to remember what you're supposed to do and when. Your mind is freed up to focus on solving the problem, and TDD is becoming your default way of working. You'll be no less productive TDD-ing than you were befpre (maybe even more productive), and the code you produce will be more reliable and easier to change.

The Team Dojo: Some teams are keen to put their new TDD skills to the test. An exercise I've seen work well for this is my Team Dojo. It's a sufficiently challenging problem, and really works on those individual skills as well as collaborative skills. Afterwards, you can have a retrospective on how the team did, examining their progress (customer tests passed), code quality and the disciplie that was applied to it. Even in the most experienced experienced teams, the doj will reveal gaps that need addressing.

Graduation: TDD is hard. Learning to test-drive code involves all sorts of dev skills, and teams that succeed tell me they feel a real sense of achievement. It can be good to celebrate that achievement. Whether it's a party, or a little ceremony or presentation, when organisations celebrate the achievement with their dev teams, it shows reall commitment to them and to their craft.

Of course, you don't have to do it my way. What's important is that you start slow and burn your pancakes away from the spotlight of real projects with real deadlines. Give yourself the space and the safety to get it wrong, and over time you'll get it less and less wrong.

If you want to talk about adopting TDD on your team, drop me a line.




June 10, 2018

Learn TDD with Codemanship

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June 8, 2018

Learn TDD with Codemanship

The Entire Codemanship TDD Course Book - Absolutely Free

Changes are afoot with my code craft training and coaching company, Codemanship, and as part of that, I'm making my 222-page TDD course book available to download as a spiffy full-colour PDF for free.



It covers everything from the basics of Red-Green-Refactor, through software design principles to apply to your growing code, all the way up to advanced topics other TDD books and courses don't reach, like mutation testing, property-based and data-driven testing and Continuous Inspection. Many people who've read the book have commented on how straightforward and to-the-point it is. Shorter than most TDD/code craft books, but covers more, all in practical detail.

Of course, to get the best from the book, you should try the exercises.

Better still, try the exercises with the guy who wrote the book in the room to guide you.





May 25, 2018

Learn TDD with Codemanship

Ever-Decreasing Cycles - I Called It Right

I'm right about something roughly once in a decade, if I'm lucky. Looking back over 13 years of blog posts, I nominate this little gem as a candidate for "That Thing I Called Right", which predicted that - as our computers grew ever more powerful - continuous background code review would become a thing.

The progression seemed perfectly logical. At the time I wrote it, we'd seen the advent of continuous background code compilation, giving us instant feedback when we make silly syntax errors. Younger developers may not be aware of just what a difference that made to those of us who remember compiling the code involving going away to get a coffee (or lunch, or dinner and a show). So much time saved!

With less brain power dedicated to "does it run?", we were freed up to think about a higher question: does it work?. In 2008, continuous background testing tools like Infinitest and JUnitMax were becoming more popular. Today, I see them quite widely used, and can easily foresee a time when we're all using them within the next decade.

So we've progressed from "does it run?" to "does it work?" as our computers have increased their processing power, and the next evolution I predicted was to continuously ask "will it be easy to change?" At the time, the majority of code analysis tools took too long to do what they did to be running continuously in the background alongside compilation and functional testing. (There were one or two adventurous experimental tools, but we haven't heard much from them in the meantime.)

With Microsoft's Roslyn compiler, continuous background code review is now finally a thing. We can write code quality checks and build them into the compilation pipeline, creating feedback on things like variable names, method size and complexity, couplings, and all that stuff we care about for maintainability, in real time, as we type the code. I suspect such a capability will be added to other compiler platforms in the next decade or so.

Sure, it's still early days, and my experiments with it suggest computing power needs maybe one or two more iterations to rise to meet the number-crunching challenge, but in a practical form that we can begin using today - just like those plucky pioneers who ventured out with Infinitest in the early days it's here. There'll be a learning curve. Start climbing it now, is my recommendation.

My hope for continuous background code review is that it will yet again free up our minds to focus on more important questions, like "is this what they really need?"

And that will be a great day for software.


* And, yes, I had hoped I'd been right about high-integrity software becoming mainstream, but interest in that has flat-lined these past 20 years. Maybe next year... Ho hum.



April 28, 2018

Learn TDD with Codemanship

8 Rules of Maintainable Code: A Handy Cut-Out-And-Keep Chart

If you've been on the Codemanship TDD training course, you may vaguely recall the first afternoon when we discuss design principles and how they can shape our code as it emerges.

I posit 8 principles that I ask participants to apply to the exercises, drawing from Simple Design, "Tell, Don't Ask" and S.O.L.I.D. These 8 factors are interrelated, and form a kind of virtuous - if somewhat complex - virtuous circle.

Code that's easier to change tends to be easier to test quickly. Fast-running tests make refactoring easier. Which helps us make our code easier to change. And around we go.

We don't do slides on the course (hoorah!), but I'm trying this morning to visualise these 8 principles and how they relate to each other in a single graphic.

There's the simple version:



And this is my latest iteration, to print off and hang on your toilet wall or put on a spiffy t-shirt. All non-profit uses are fine.



Going beyond maintainability, there's also a relationship between Clean code and reliability. Code that can be tested very quickly tends to have far fewer bugs. And code that's simpler and easier to understand is likely to get broken when we change it. So, it's more of a virtuous triangle, really.




April 11, 2018

Learn TDD with Codemanship

The Foundation of a Dev Profession Should Be Mentoring

What makes something like engineering or law or medicine a "profession"? Ask me 20 years ago, I'd have said it was standards and ethics, policed by some kind of professional body and/or the law. There are certain things, say, an electronic engineer isn't supposed to do, certain things you can't ask your doctor for, certain things a lawyer would end up in jail for doing.

Ask me today, and my answer would be this: a profession is a community of people following a vocation - like writing software or teaching children - that professes how it works to people who want to learn how to do it.

Experienced school teachers help people learning to be school teachers how to teach. They pass on the benefit of their experience, including all the stuff an even more experienced teacher passed on to them.

I still very much believe that standards and ethics must be part of a profession of software development. But I'm increasingly convinced that the bedrock of any such profession would be mentoring. I think of all the time I wasted in my early years of programming, and all the things that would have helped enormously to know back then. Even programming for fun in my teenage bedroom would have been made easier with some basic code craft like unit testing and rudimentary version control.

I was very lucky to be exposed to much more experienced "software engineers" who nudged me firmly in the direction of rigorous user-centred iterative software development, mentioning books I should read, newsgroups I should visit, courses I should go on, and showing me with their day-to-day examples techniques I still apply - and teach - today.

I make it my business today to pass on the benefits of the mentoring I received.And that, to my mind, should be the basis for a profession of software development.

For that to work, though, it's necessary that developers stay developers. "Use it or lose it" has never been more true than in software. I see developers I coached 10 years ago get promoted into management roles - sheesh, I know a lot of CTOs, according to LinkedIn - and quickly lose their coding abilities and fall behind with the technology. Their experience might be invaluable to someone starting out, but it's hard to lead by example if the last programming you did was in Visual C++ 6.0 and your junior devs are working in F#.

So, another pillar of this professional foundation must necessarily be parallel career progression - up to CTO equivalent - for developers. Looking for work for the first time in a decade has left me in little doubt that - with a handful of glorious exceptions that I'm exploring - many employers don't want older (i.e., more expensive) developers, and even the most senior dev roles typically pay a lot less than management equivalents. I meet a lot of senior managers who are reluctantly in this roles because they have big mortgages and school fees to pay. They'd much rather have stayed hands-on. If the best potential mentors are disappearing into meeting rooms all day, it will always be impossible to square this circle.

The idea's been floated before - including by me - but I think it's finally time to start a software developer's guild, with a specific purpose of championing long-term mentoring and parallel career progression for devs who want to stay devs.

Who's with me?




April 6, 2018

Learn TDD with Codemanship

Could Refactoring (& Refuctoring) Help Us Test Claims About Benefits of Clean Code

One of the more frustrating things about teaching developers about code craft and "Clean Code" is the lack of credible hard evidence from respectable sources about the claimed benefits of it.

Not only does this make code craft a tougher sell to skeptics - and there was a time when I was one of them, decades ago - but it also calls into question whether the alleged benefits are real.

The biggest barrier to doing research in this area has been twofold:

1. The lack of data points. Most software engineering academic studies take data from a handful of projects. If this were, say, medical research, we'd never get our medicines on to the market.

2. The problem of comparing apples with apples. There are so many factors in software development that it's pretty much impossible to isolate one and rule out all others. Studies into the effects of adopting TDD can't account for the variations in experience and ability, for example. Teams new to TDD tend to have to deal with a steep learning curve before they become productive again.

When I consider some of the theories about what makes code harder to change - the central plank of the code craft thesis - some we have strong evidence to back them up, others... not so much.

I've had a bit of a brainwave in this area that might help researchers. Take a code base, then specifically vary it along a single dimension. e.g., refactor to remove duplication, or "refuctor" to introduce duplication (by inlining functions and modules). The resulting variants should all be functionally equivalent, but you could fine-grain the levels of variation. Then ask developers to make changes to the logic, and measure how much code had to be edited to achieve those changes. Automated acceptance tests would ensure that every change was logically equivalent.

I can easily envisage how refactoring (and it's evil twin, refuctoring) could be used to vary readability, complexity, duplication, coupling and cohesion (e.g., by moving methods between classes to introduce or eliminate feature envy), "swabbability" (e.g., by introducing dependency injection, or by reversing the dependency inversion by using explicit references to concrete implementations of interfaces) and a range of other code qualities. Automated tests could ensure that every variant still works exactly the same way on the outside.

And the tests themselves could be varied. For example, you could manipulate test suite execution time so that in some cases developers had to wait an hour for feedback, while others only need wait seconds for the same feedback.

I think I might be on to something. What do you think?


March 24, 2018

Learn TDD with Codemanship

Code Craft: What Is It, And Why Do You Need It?

One of my missions at the moment is to spread the word about the importance of code craft to organisations of all shapes and sizes.

The software craftsmanship (now "software crafters") movement may have left some observers with the impression that a bunch of prima donna programmers were throwing our toys out of the pram over "beautiful code".

For me, nothing could be further from the truth. It's always been clear in my mind - and I've tried to be clear when talking about craft - that it's not about "beautiful code", or about "masters and apprentices". It has always been about delivering software that works - does what end users need - and that can be easily changed to solve new problems.

I learned early on that iterating our designs was the ultimate requirements discipline. Any solution of any appreciable complexity is something we're unlikely to get right first time. That would be the proverbial "hole in one". We should expect to need multiple passes at it, each pass getting it less wrong.

Iterating software designs requires us to be able to keep changing the code over and over. If the code's difficult to change, then we get less throws of the dice. So there's a simple business truth here: the harder our code is to change, the less likely we are to deliver a good working solution. And, as times goes on, the less able we are to keep our working solution working, as the problem itself changes.

For me, code craft's about delivering the right thing in the short-to-medium term, and about sustaining the pace of innovation to keep our solution working in the long term.

The factors involved here are well-understood.

1. The longer it takes us to re-test our software, the bigger the cost of fixing anything we broke. This is supported by a mountain of evidence collected from thousands of projects over several decades. The cost of fixing bugs rises exponentially the longer they go undetected. So a comprehensive suite of good fast-running automated tests is an essential ingredient in minimising the cost of changing code. I see it being a major bottleneck for many organisations, and see the devastating effect long testing feedback loops can have on a business.

2. The harder it is to understand the code, the more likely it is we'll break it if we change it.

3. The more complex our code is, the harder it is to understand and the easier it is to break. More ways for it to be wrong, basically.

4. Duplication in our code multiplies the cost of changing common logic.

5. The more the different units* in our software depend on each other, the wider the potential impact of changing one unit on other units. (The "ripple effect").

6. When units aren't easily swappable, the impact of changing one unit can break other modules that interact with it.

* Where a "unit" could be a function, a module, a component, or a service. A unit of reusable code, essentially.

So, six key factors determine the cost of changing code:

* Test Assurance & Execution Time
* Readability
* Complexity
* Duplication
* Coupling
* Abstraction of Dependencies

Add to these, a few other factors can make a big difference.

Firstly, the amount of "friction" in the delivery pipeline. I'd classify "friction" here as "steps in releasing or deploying working software into production that take a long time and/or have a high cost". Manually testing the software before a release would be one example of high friction. Manually deploying the executable files would be another.

The longer it takes, the more it costs and the more error-prone the delivery process is, the less often we can deliver. When we deliver less often, we're iterating more slowly. When we iterate more slowly, we're back to my "less throws of the dice" metaphor.

Frequency of releases is directly related also to the size of each release. Releasing changes in big batches has other drawbacks, too. Most importantly - because software either works as a whole or it doesn't - big releases incorporating many changes present us with an all-or-nothing choice. If change X is wrong, we now have to carefully rework that one thing with all the other changes still in place. So much easier to do a single release for change X by itself, and if it doesn't work, roll it back.

Another aside factor to consider is how easy it is to undo mistakes if necessary. If my big refactoring goes awry, can I easily get back to the last good state of the code? If a release goes pear-shaped, can we easily roll it back to a working version, with minimal disruption to our end customer?

Small releases help a lot in this respect, as does Version Control and Continuous Integration. VCS and CI is like seatbelts for programmers. It can significantly reduce lost time if we have a little accident.

So, I add:

* Small & Frequent Releases
* Frictionless Delivery Processes (build-test-deploy automation)
* Version Control
* Continuous Integration

To my working definition of "code craft".

Noted that there's more to delivering software than these things. There's requirements, there's UX, there's InfoSec, there's data management, and a heap of other considerations. Which is why I'm clear to disambiguate code craft and software development.

Organisations who depend on software need code that works and that can change and stay working. My belief is that anyone writing software for a living needs to get to grips with code craft.

As software continues to "eat the world", this need will grow. I've watched $multi-billion on their knees because their software and systems couldn't change fast enough. As the influence of code spreads into every facet of life, our ability to change code becomes more and more a limiting factor on what we can achieve.

To borrow from Peter McBreen's original book on software craftsmanship, there's a code craft imperative.



March 16, 2018

Learn TDD with Codemanship

Lamenting the Golden Age of High-Integrity Software That Never Came

When I was a much younger programmer, I read a paper that had a big impact on the way I thought about software integrity.

Up to then, I - like so many - believed that "software has bugs". It seemed inevitable. Because all the software I'd seen had bugs. And all the software I'd written had bugs. We just have to live with it, right?

And then along came this paper on a thing called Cleanroom Software Engineering, and my mind was blown.

IBM wrote a COBOL pre-compiler that had about 85,000 lines of code and zero bugs reported in production. Not one. Ever. And what really struck me is that - bearing in mind how primitive dev tools were in the 1980s - it only took a team of six, achieving an average dev productivity that was measurably higher than the industry average. Also, the cost of maintaining the product - typically a lot higher than the cost of initial development - was relatively low; just one developer-year per year. Because nobody was bug fixing.

Now, of course, compared to software today 85 KLOC isn't much. But it's not insignificant, statistically. Maybe an equivalent product today would have 20x as much code. But what's 20x zero?

A single paper turned my whole worldview about software integrity (vs. productivity) upside-down. I've been lucky enough to experience this kind of approach - not specifically Cleanroom, but along similar lines - since, and seen the results for myself. Seeing is believing, and - praise Knuth! - I'm a believer!

So you can probably imagine my frustration to see how, 20 years later, the "software has bugs" paradigm still dominates. Who out there is producing very high-integrity code? Vanishingly few. I've waited and waited for high-integrity development techniques to catch on. I've even stirred the pot a few times myself with attempts at training products and talks with various publishers about a book that updates the ideas for the hipster Agile generation. To no avail. Still, vanishingly few are interested.

It's not as if there isn't a compelling business case. More reliable code, for little to no extra cost (you might even save time and money)? Lower maintenance costs? Happier customers? A world of digital stuff we can rely on? What's not to like? It's not as if these techniques are incompatible with Agile, either. I've done both at the same time, for real.

But for every person like me out there selling the dream, there are 10 more actively briefing against it. "Quick and dirty". "Move fast and break stuff". "Perfection is the enemy of good enough." Etc etc etc.

It's an easy sell to managers who don't understand the relationship between quality, time and cost. Cut some corners, get there sooner, save some money. A much harder proposition is "take more care, get there sooner, save some money". Bosses don't believe it. Heck, most devs don't believe it, despite the mountain of strong evidence to back it up.

I still live in hope that - one day - high-integrity software will go mainstream. The tools and techniques are not, despite what you may have heard, rocket science. Most devs are smart, and most devs could learn to do this. I did, so it can't be that difficult.







March 11, 2018

Learn TDD with Codemanship

Proposing The xUnit "Meta-Kata"

A while back I ruminated on refactoring old-fashioned "test it all with a main method" test code (like we did back in the day) into the xUnit unit test framework pattern.

It occurred to me that this might make a good code kata. TDD a well-known kata (e.g., FizzBuzz, Bowling Game, "Rock, Paper, Scissors"), but starting without a unit testing framework doing it all in a single main method.

As the code evolves, refactor the test code to remove code smells like methods testing more than one thing, classes testing more than one "unit" or "feature" (depending on how you roll), high-level modules that depend directly on low-level test fixtures, multiple tests being different examples of the same test, and so on.

It could be an interesting exercise in discovering frameworks. Perhaps it'll take multiple katas for a complete xUnit framework to reveal itself, just as so many great and useful frameworks don't really take shape until they've been reused a few times on other problems.

It might also be an exercise in applying the TDD discipline on two problems simultaneously; a test of your Craft Fu.

Really, it would be a kata within a kata: a meta-kata, if you like. And as such, I think it could be really interesting and rather challenging. I'll hopefully be giving it a go - well, probably a few goes - when I pair with my "apprentice" Will Price soon. When I think we've cracked it, I'll post a screencast and the code (with version history, so you can play it back).