Wednesday, December 17, 2014

Working Effectively with Unit Tests Official Launch

Today marks the official release release of Working Effectively with Unit Tests. The book is available in various formats:
I’m very happy with the final version. Michael Feathers wrote a great foreword. I incorporated feedback from dozens of people - some that have been friends for years, and some that I’d never previously met. I can’t say enough great things about http://leanpub.comand I highly recommend it for getting an idea out there and making it easy to get fast feedback. 

As far as the softcover edition, I had offers from a few major publishers, but in the end none of them would allow me to continue to sell on leanpub at the same time. I strongly considered caving to the demands of the major publishers, but ultimately the ability to create a high quality softcover and make it available on Amazon was too tempting to pass up.

The feedback has been almost universally positive - the reviews are quite solid on goodreads ( I believe the book provides specific, concise direction for effective Unit Testing, and I hope it helps increase the quality of the unit tests found in the wild.

If you'd like to try before you buy, there's a sample available in pdf format or on the web.

Monday, August 25, 2014

The Case for Buying Technical Books

In the past few months I've seen more than a few articles encouraging programmers to write books. Each article provides at least a bit of good advice, and proceeds to conclude with the same idea:
You should write a book to build your brand.
I find this conclusion accurate and extremely disappointing. If the overwhelming reason to write a book is brand building, then the pool of potential authors is restricted to people who would benefit from brand building (and people who don't value their time).
How Did We Get Here?
The Internet, obviously. Practically everyone knows how to download any movie, song, or book at no cost. Opinions on "illegal downloading" range from opposition to pride. I'm not particularly interested in discussing those opinions; however, I believe it's worth observing the impact of the combination of ability and desire to acquire content without compensating the creator.
“Books aren't written - they're rewritten...” -- Michael Crichton
If you've never written a book, you may not be aware of colossal effort it takes to write a mediocre book. When it's all said and done, it can take well over an hour of effort per page. Great books, such as Java Concurrency in Practice, require an even greater level of attention to detail, and cost even more time to create. Brian Goetz estimates that it took them approximately 2,400 hours to create JCiP. If we also knew their royalty structure and the number of copies sold, we'd be able to calculate the hourly rate for writing a high quality book.
It turns out, one of the recent articles encouraging writing gives you royalty numbers and a hint on how many copies a quality book might sell.
Royalties for print should start at 18% of net revenues to the publisher. (Expect that figure to be around $10-20, so you're only making a few dollars on each sale.)
Selling 10 thousand copies of a print tech book these days is a solid success and should be compensated accordingly. -- Obie Fernandez
Let's assume JCiP was more than a solid success and sold 20K copies (doubling Obie's "solid success" benchmark). Assuming they negotiated royalties well, that would mean making $40,000 - thus the hourly rate for writing JCiP would be under $17 per hour.
Clearly I've made a few assumptions, but I believe all of them are based on sound logic. As long as you work 8 hours a day, 5 days a week, for 50 weeks and write a modern classic, you'll make around $34,000 per year. Anecdotal evidence among my author friends who've yet to write a modern classic is worse: the hourly rate is less than minimum wage.
The royalty structures combined with lessening sales create an environment where writing a book for (royalty) profit isn't a reasonable use of your time. As a result, the majority of today's authors are either consultants or unknown programmers. Established, non-consultant programmers gain little from the brand building aspect of writing a book, and likely make far more than $34,000 a year at their full-time jobs - why would they take on a poorly paying second job?
Around 2005 it became fairly easy to download, for free, practically any book. It might be coincidence that 10 of 13 of these Must-Read books were written prior to 2005. Despite the possibility, I don't believe it's a coincidence. Rather, I believe that at one time it paid to create a best selling technical book, and people with various backgrounds took up the challenge.
Nice Assumption Filled History Lesson, What's Your Point?
My point is fairly simple. If you're, like I am, tired of having to choose between books written decades ago and books written by those with at least a slightly ulterior motive, buy some books. Does your company have a book buying policy? If you aren't spending your entire book budget, why not? It costs you nothing to buy a book and give it to a teammate, and every royalty penny reminds an author that someone cares about all of those hours writing and rewriting.
Even if your company doesn't have a book budget, ask yourself if you'd rather your next book about Java be written by a consultant you've never heard of or Java's language architect. The average technical book costs little compared to life's other expenses, and buying a technical book is investing in your profession twice. You stand to gain knowledge both from today's book purchase and a potential future book written by the same author - a future book that may never be written given the current financial incentives.
If you're a CTO, Director or Manager, why aren't you constantly buying books for the developers you work with? They could probably use your advice on which books will best guide their careers.
Makes Sense, What Should I Buy?
There are several good books now available on leanpub - where the authors are paid significantly higher royalties. If you want to support authors you should always start there. From there I would own at least a copy of Chad's (previously referenced) Must-Read books. I'd also buy Chad's Passionate Programmer. Finally, you can't go wrong working your way through this list: Clojure Bookshelf.

Wednesday, July 16, 2014

Solitary Unit Test

Originally found in Working Effectively with Unit Tests

It’s common to unit test at the class level. The Foo class will have an associated FooTests class. Solitary Unit Tests follow two additional constraints:
  1. Never cross boundaries
  2. The Class Under Test should be the only concrete class found in a test.
Never cross boundaries is a fairly simple, yet controversial piece of advice. In 2004, Bill Caputo wrote about this advice, and defined a boundary as: ”...a database, a queue, another system...”. The advice is simple: accessing a database, network, or file system significantly increases the the time it takes to run a test. When the aggregate execution time impacts a developer’s decision to run the test suite, the effectiveness of the entire team is at risk. A test suite that isn’t run regularly is likely to have negative-ROI.

In the same entry, Bill also defines a boundary as: ”... or even an ordinary class if that class is ‘outside’ the area your [sic] trying to work with or are responsible for”. Bill’s recommendation is a good one, but I find it too vague. Bill’s statement fails to give concrete advice on where to draw the line. My second constraint is a concrete (and admittedly restrictive) version of Bill’s recommendation. The concept of constraining a unit test such that ‘the Class Under Test should be the only concrete class found in a test’ sounds extreme, but it’s actually not that drastic if you assume a few things.
  1. You’re using a framework that allows you to easily stub most concrete classes
  2. This constraint does not apply to any primitive or class that has a literal (e.g. int, Integer, String, etc)
  3. You’re using some type of automated refactoring tool.
There are pros and cons to this approach, both of which are examined in Working Effectively with Unit Tests.

Solitary Unit Test can be defined as:
Solitary Unit Testing is an activity by which methods of a class or functions of a namespace are tested to determine if they are fit for use. The tests used to determine if a class or namespace is functional should isolate the class or namespace under test by stubbing all collaboration with additional classes and namespaces.

Monday, June 30, 2014

Working Effectively with Unit Tests Rough Draft Complete

I finally put the finishing touches on the rough draft of Working Effectively with Unit Tests. It's been an interesting journey thus far, and I'm hoping the attention to detail I've put into the rough draft will translate into an enjoyable read.

What I did poorly: I'd written the book's sample before I ever put it on leanpub. Before a book is published you can collect contact and price information from those who are interested. However, once you publish and begin selling, you no longer have the ability to collect the previously mentioned information. I published and began selling my book immediately - and forfeited my chance to collect that information.

What I did well: I published early and often. I can't say enough nice things about leanpub. I've gotten tons of feedback on example style, writing style, typos, and content. One reader's suggestion to switch to Kevlin Henney's Java formatting style made my book enjoyable to read on a Kindle. I had twitter followers apologizing for "being pedantic and pointing out typos", and I couldn't have been happier to get the feedback. Each typo I fix makes the book more enjoyable for everyone. If you're going to write a book, get it on leanpub asap and start interacting with your audience.

What I learned from Refactoring: Ruby Edition (RRE): RRE contains errors, far too many errors. I vowed to find a better way this time around, and I'm very happy with the results. Every example test in the book can be run, and uses classes also shown in the book. However, writing about tests is a bit tricky: sometimes "failure" is the outcome you're looking to document. Therefore, I couldn't simply write tests for everything. Instead I piped the output to files and used them as example output in the book, but also as verification that what failed once continued to fail in the future (and vice versa). WEwUT has a script that runs every test from the book and overwrites the output files. If the output files are unchanged, I know all the passing examples are still correctly passing, and all the failing examples are still correctly failing. In a way, git diff became my test suite output. I'm confident in all the code found in WEwUT, and happy to be able to say it's all "tested".

What's unclear: Using leanpub was great, but I'm not really sure how to get the word out any further at this point. I set up a page and many friends have been kind enough to tweet about it, but I don't really have any other ideas at this point. I've reached out to a few publishers to see about creating a paperback, and I suspect a print version will increase interest. Still, I can't help thinking there's something else I should be doing between now and paperback launch.

What's next: The rough draft is 100% complete, but I expect to continue to get feedback over the next month or so. As long as the feedback is coming in, I'll be doing updates and publishing new versions.

If you've already bought the book, thank you for the support. It takes 10 seconds to get a pdf of any book you want these days, and I can't thank you enough for monetarily supporting all the effort I've put into WEwUT. If you haven't bought the book, you're welcome to give the sample a read for free. I hope you'll find it enjoyable, and I would gladly accept any feedback you're willing to provide.

Wednesday, May 21, 2014

Working Effectively with Unit Tests

Unit Testing has moved from fringe to mainstream, which is a great thing. Unfortunately, as a side effect developers are creating mountains of unmaintainable tests. I've been fighting the maintenance battle pretty aggressively for years, and I've decided to write a book that captures what I believe is the most effective way to test.

From the Preface

Over a dozen years ago I read Refactoring for the first time; it immediately became my bible. While Refactoring isn’t about testing, it explicitly states: If you want to refactor, the essential precondition is having solid tests. At that time, if Refactoring deemed it necessary, I unquestionably complied. That was the beginning of my quest to create productive unit tests.

Throughout the 12+ years that followed reading Refactoring I made many mistakes, learned countless lessons, and developed a set of guidelines that I believe make unit testing a productive use of programmer time. This book provides a single place to examine those mistakes, pass on the lessons learned, and provide direction for those that want to test in a way that I’ve found to be the most productive.
The book does touch on some theory and definition, but the main purpose is to show you how to take tests that are causing you pain and turn them into tests that you're happy to work with.

For example, the book demonstrates how to go from...

looping test with many (built elsewhere) collaborators
.. to individual tests that expect literals, limit scope, explicitly define collaborators, and focus on readability
.. to fine-grained tests that focus on testing a single responsibility, are resistant to cascading failures, and provide no friction for those practicing ruthless Refactoring.
As of right now, you can read the first 2 chapters for free at

I'm currently ~25% done with the book, and it's available now for $14.99. My plan is to raise the price to $19.99 when I'm 50% done, and $24.99 when I'm 75% done. Leanpub offers my book with 100% Happiness Guarantee: Within 45 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks. Therefore, if you find the above or the free sample interesting, you might want to buy it now and save a few bucks.

Buy Now here: