XUnit: Beyond the Fact Attribute (Part 2)

One thing I initially missed about NUnit compared to XUnit (besides built-in support for it in tools like TeamCity) is attributes like SetUp and TestFixtureSetUp that enable you to decorate a method with variables that need to be set (or any other logic that needs to run) before each test or before all the tests in a test fixture.  When I first adopted test-driven development as a work practice, I felt it made things easier.  But the authors of NUnit eventually came to a different conclusion about those attributes, and implemented XUnit without those attributes as a result.

Rather than define attributes for per-test and per-fixture setup, the authors of XUnit recommend using a no-arg constructor where you’d use SetUp and IUseFixture where you’d use TestFixtureSetUp or TestFixtureTearDown.  While this took me some time to get used to, leveraging the interface made it easier to handle the external dependencies of code I needed to implement and test.  One technique I’ve adopted to give myself additional flexibility in my test implementations is to add an extension point to the implementation of the SetFixture method

In this example, the extension point is a method named AdditionalFixtureConfiguration.  Calling it inside SetFixture ensures it will be called before each test class derived from UnitTestBase.  Making the method virtual and keeping it free of implementation means that I only need to override it if I need additional pre-test setup for particular test scenarios.  Because we use StructureMap as our IOC container, the equivalent of UnitTestFixture class in my example has a public attribute of type StructureMap.IContainer.  The AdditionalFixtureConfiguration method provides a natural home for any setup code needed to configure additional mappings between interfaces and implementations, set up mocks, and even inject mocks into the container if a concrete implementation isn’t available (or isn’t needed).

While this is the implementation I’ve chosen, there are certainly other ways to accomplish the same thing.  Instead of defining AdditionalFixtureConfiguration in UnitTestBase, I could define it in UnitTestFixture instead and call it in every SetFixture implementation (or not , if that customization wasn’t needed).  I prefer having the abstract class because it makes for simpler actual test code.

Everyone is Junior at Something–Even You

Hanselminutes #427  was an excellent interview with Jonathan Barronville, the author (perhaps the most intelligent and articulate 19-year-old I’ve ever heard) of this article on Medium.  The discussion covered a lot of ground, and posed a number of thought-provoking questions.  Three of the questions struck me as especially important.

What is senior?

In the podcast, Hanselman suggested three criteria: years in industry, years writing code in a language, and age.  Since I’ve been in the industry for 18 years, have been writing production C# code for about 10 of them, and turned 40 at the beginning of the year, those criteria argue in favor of me being considered senior.  Those numbers can also work against me in a way (and not just because of the field’s well-known problems with age discrimination).  Before I took my current job (over 2 years ago), I hadn’t written any production ASP.NET MVC, jQuery or knockout.js.  The last time I’d written any production JavaScript before then was before also jQuery and node.js even existed.  So from the perspective of those technologies, I was junior (and still am in some respects).

While industry today seems to have a fetish for young developers, there is merit to that interest in one respect.  Men and women entering the industry right now, whether they’re fresh out of college (or even younger) are too young to have any memory of a world where Google didn’t exist.  They’re too young to remember a world before web pages.  Some of them have been writing software for the majority of their lives.  It’s natural to them in a way it wasn’t for me because I had to go to college to get access to really good computers and high-speed Internet.

That said, the number of years (or lack of them) isn’t an advantage or disadvantage if you haven’t had the sort of experiences you can grow from as a developer (and learned the right lessons from them).  Regardless of what age you were when you had the experiences, if you’ve had to build software that solved enterprise-level problems, dealt with scaling, refactoring and enhancement of large systems, or integration of systems, both succeeding and failing at addressing those challenges are what really make a senior developer.  More time in industry may give someone more opportunities to have those experiences, but if they haven’t had them, they’ve just been writing software for a long time.

What is the rush to be senior?

Hanselman made a comparison between tradesmen like carpenters and plumbers (who have to work as apprentices for 3-5 years and pass an exam before they can become journeymen) and our industry, where someone can have senior in their title without much experience.  While some of it (if not most of it) has to do with pay, there are drawbacks.  Because our field is relatively young in the grand scheme of things, there aren’t universally accepted standards and practices (especially compared to some branches of engineering, which have hundreds of years of history).  We place too much of a premium on speed, and not enough on depth of experience (and the time it takes to earn it).  One of the end results of this is the sort of interviews I’ve experienced on a regular basis.  I’ve seen tons of resumes from people with senior titles who are stymied by interview exercises that ask fairly basic questions (on the level of the Fizz Buzz test).

I’d been working for less than four years when I first got “senior” added to my title.  It came with a nice raise (which I was certainly happy about) and more responsibilities (team leadership), but I certainly wasn’t senior in terms of software development experience after that short a period of time.  Not unlike what the classic Peter Norvig essay suggests about teaching yourself programming in ten years, that’s about how long it took for me to see myself as legitimately senior from an experience perspective.  Even now, having spent over 17 years in industry, I’m sure there are workplaces where I wouldn’t be considered senior because I haven’t architected super-large systems or led a team with dozens of people—and I’m alright with that.  I’ve matured enough after this amount of time to be more concerned with what kind of work I’m doing (and what I’m learning) than I am with what title an employer gives me.

Are we okay with not knowing something and then learning?

This question points in two directions:

  • are we okay with ourselves not knowing something and then having to learn it?
  • are we okay with others not knowing something and then having to learn it?

For me, the answer to the first question is yes.  In the case jQuery and knockout.js (and other unfamiliar technologies like RavenDB), I had to be okay with not knowing.  Doing my own research, and not being too proud to ask a lot of questions younger developers on the team who clearly had more experience with those technologies was necessary to advance to the point where I could do all that work myself.

The answer to the second question is the key to many of the problems with our industry, particularly when it comes to issues of gender and diversity.  Too many in our industry go beyond not being okay with someone not knowing something and cross the line to being condescending, rude, and even hostile.  I’ve been on the receiving end of that kind of treatment more often than I care to remember.  Too many workplaces allow people with superior technical skills to act like children instead of adults in interacting with their co-workers.  There is more and more being written about the sexism in the industry (pieces like this one, and this one), but not nearly enough on the negative impact that environment has on the ability and desires of others to learn and grow as professionals.  I think the persistently low numbers of minorities and women in the tech industry has as much to do with the perception (if not reality) that a lot of tech companies have high “a**hole thresholds” as it does with insufficient exposure to math and science in school.

The bottom line for me from the article and the podcast is not only that everyone in this industry starts out as junior level, but that technology changes so quickly that we will all be junior at something at multiple points throughout our careers in the tech industry.  We need to keep that knowledge in mind so that we can be more patient with ourselves as we learn and with those we work with as they learn.

XUnit: Beyond the Fact Attribute

After using XUnit for unit testing the past couple of years, I finally got a bit tired of the cut-and-paste-and-modify cycle of expanding test coverage for functionality I was building.  I’ve used “row test” functionality in NUnit and MbUnit in the past, but hadn’t gotten around to finding out how to use them in XUnit until quite recently.  The process I followed was relatively short: (1) Add the xunit.extensions dependency to my existing test assembly, (2) take a test that class that contained significant duplication and re-factor it to leverage one of the row testing attributes available.

In my case, the area I picked that would benefit from row testing was workflow testing.  We implement our workflows as state machines with transition tables that define a starting state, an ending state, and the event that triggers the state change.  I’d previously tested these workflows with one unit test per transition, with those three attributes (start state, end state, event) being the only thing different between them.  This meant a single test  that took these attributes as parameters should be sufficient to test transitions, and that the row testing attribute(s) would contain the actual values.

The Theory attribute supports a number of different data sources, including inline data, Excel data, and SQL Server data.  I started with inline data believing it would be the simplest.  But I wasn’t able to get that to work because the InlineData attribute of Theory only appears to support primitives (int, bool, string, etc).  Our workflow events and statuses are classes with attributes that are static and read-only.  From there, I moved on to try the PropertyData attribute.  This attribute takes one string argument that needs to match the name of a property added to the test class that returns a collection of object arrays with one set of test parameters per entry.

Following that approach worked much better.  The results display pretty nicely in ReSharper as well:


I’m still working on a code example of this to make available on GitHub, but here are a few links I found useful in getting up to speed with the additional capabilities of XUnit:

Learning New Programming Languages

Important advice from The Pragmatic Programmer (page 62):

“Learn at least one new language every year.”

It’s advice I’ve been trying to follow more seriously since I first started reading the book last month.  One site I’ve been using to learn more JavaScript that’s proven to be pretty cool for that is codewars.com (thanks Dean).  The katas are small enough that it doesn’t take a ton of research to figure out how to do something in a language you’re learning.  Once you’ve developed a working solution, you can see how others have solved it (and compare your solution to theirs).  Since you write and test the katas in the browser, there’s none of the overhead of firing up an editor or uploading your solution somewhere.  Ideally I’d be writing a few katas per day, but a few katas a week are what I’ve been able to manage so far.

Since Apple introduced yet another language (Swift) at WWDC earlier this week, I’m starting to learn that language as well.  So far, the syntax is a lot easier to grasp than Objective-C.  The only real hassle with writing the code examples as I read the language guide is that XCode 6 Beta crashes every half hour.

With both languages (or any language really), the real leap forward comes from building something non-trivial with them. Figuring out what that non-trivial something will be is another challenge altogether. I wish there were a sites like codewars.com (or Project Euler) that put out larger-scale problems intended to be solved with software. Being part of the developer interview loop at work pushed me to create a few problems of that sort for use in interviewing developer candidates, but none of those exercises require more than 20 minutes of work. More significant challenges should make it useful to explore features beyond basic control flow and data structures.