Fluent-ish interfaces

This evening I was reading a post on Jason Gorman's blog about fluent assertions in unit tests and it made me smile.  Jason was updating some slides for a workshop and decided to illustrate fluent assertions by putting the "classical" assertion right next to the fluent version.  After doing that, he started to doubt the text on the slide that claimed the fluent version is easier to read than the classical one.

That made me feel good, because I've often wondered the same thing.  I've heard the the assertion that fluent assertions are easier to read many times - for instance, they said that in a Certified Scrum Developer class I took last year.  Apparently that's just "the direction the industry is going."  I've followed Jason's blog for a while and he seems like a pretty smart guy, so seeing him doubt the received wisdom gives me a little validation that it's not just me.  

Fluent assertions are...sort of fine, I guess.  I mean, they work.  They're not terrible.  I never really thought they were any easier to read than the old-fashioned assertions, though.  

From what I can tell, the claim is generally that fluent interfaces are easier to read because they naturally read more like a sentence.  And that's definitely true - they undeniably read more like a sentence.  Just look at some of Jason's examples (classical above, fluent below):

Assert.AreEqual(50, 50);
Assert.That(50, Is.EqualTo(50));

Assert.IsTrue(true);
Assert.That(true);

Assert.AreSame(payer, payee);
Assert.That(payer, Is.Not.SameAs(payee));

Assert.Contains(1, new ArrayList() {1, 2, 3});
Assert.That(new ArrayList() {1, 2, 3}, Contains.Item(1));

It's undeniable that "assert that 50 is equal to 50" is much closer to a real sentence than "assert are equal of 50 and 50" (or however you would read the classical version).  However, it would behoove us to remember that we're reading code here, not English prose.  We can't just assume that making your code read like an English sentence makes it more readable.  They're different things.

My theory is that we tend to think differently when we're looking at code than we do when we're reading text.  The fluent version might look closer to a sentence, but that's really just on the surface.  It's only more natural if you mentally strip out all the punctuation.  But that's not how we read code, because in code you can't just strip out the punctuation.  The punctuation is important.  Likewise, the order of things is important, and not necessarily the same as in English.

When I look at the fluent assertion, I don't just see "assert that 50 is equal to 50", I see all the pieces.  I mentally separate the "assert" from the "that", because "that" is a method, which usually means it contains the more immediately applicable information.  Likewise with "is equal to".  And, of course, I recognize Is.EqualTo(50) as a method call, which means that I have to mentally substitute the result of that into the second parameter.  But wait a minute - equal to what?  There's only one parameter to EqualTo, which doesn't make any sense.  Oh, wait, that's NUnit magic.  So we pass 50 and the result of EqualTo to That...what the heck does "that" mean anyway?  Wait - magic again.  We have to read that backwards.  So the actual assertion comes at the end and the "that" just ties things together.  OK, I've got it now.  So...what were we testing again?

OK, maybe that's a little silly, but you get the idea.  The point is that code is written in a certain way, and it's not the way English is written.  When you're reading code, you get into a certain mindset and you can't easily just switch to a different one because the next line just happens to call a fluent interface.  The old-fashioned Assert.AreEqual(50, 50) might not be sexy or natural looking, but it's short, simple, and perfectly clear to any developer worth his salt.  Why switch to an interface that's wordier and less aligned with how the rest of our code is written?  If it ain't broke, don't fix it.  

LnBlog: Blogging the redesign

Today, we're going to talk a little about design and refactoring.  As a case-study, we're going to use a little blogging application called LnBlog.  You probably haven't heard of it - it's not very popular.  However, you have used it, at least peripherally, because it's running this site.  And you also have at least a passing familiarity with the author of that application, because it's me. 

Motivation

Software is an "interesting" field.  The cool new technologies, frameworks, and languages get all the press and they're what everybody wants to work with.  But let's be honest: it's generally not what makes the money.  I mean, how could it be?  It just came out last week!

No, if you have the good fortune to work on a grown-up, profitable product, it's almost certainly going to be the "old and busted" tech.  It might not be COBOL or Fortran, but it's almost certainly "legacy code".  It might be C++ or Java or, in our case, PHP, but it's probably old, poorly organized, lacking unit tests, and generally hard to work with.

I work on such a product for my day job.  It's a 10-year-old PHP codebase, written in an old-fashioned procedural style.  There are no unit tests for the old code, and you couldn't really write them even if you wanted to.  Sure, there's a newer part with proper design, tests, etc., but the old code is the kind of stuff that "works for the most part", but everybody is afraid to touch it because it's so brittle and tightly coupled that God alone knows what will break when you make a change.

This also applies to LnBlog.  It was my very first PHP application.  I started it way back in early 2005, in the bad old days of PHP 4.  Over the next two or three years, I managed to turn it into something that was relatively functional and full-featured.  And for the last ten years or so, I've managed to keep it working.

Of course, it hasn't gotten a whole lot of love in that time.  I've been busy and, for the most part, it worked and was "good enough".  However, I occasionally need to fix bugs or want to add features, and doing that is a truly painful process.  So I would very much like to 

The Issue

Let me be honest: I didn't really know what I was doing when I wrote LnBlog.  I was about four years out of school and had only been coding for about six or seven years total.  And I was working mostly in Visual Basic 6 at the time, which just barely counts.  It was also only my third web-based project, and the first two were written in classic ASP and VBScript, which also just barely counts.

As a result, it contains a lot of questionable design decisions and overly-complicated algorithms.  The code is largely procedural, kind of buggy, and makes poor use of abstraction.  So, in short, it's not great.

But, in fairness to myself, I've seen worse.  In fact, I've seen a lot worse.  It does have a class hierarchy for the domain objects (though it's a naive design), an abstraction layer for data access (though it's inconsistently used), and a templating system for separating markup from domain logic (though the templates are an ungodly mess).  And it's not like I had a role model or mentor to guide me through this - I was figuring out what worked on my own.  So while it's not great, I think it's actually surprisingly good given the circumstances under which it was built.

The Goal - Make the Code "Good"

So I want to make LnBlog better.  I've thought about rewriting it, but decided that I wouldn't be doing myself any favors by going that route.  I also hold no illusions of a grand re-architecture that will fix all the problems and be a shining beacon of design perfection.  Rather, I have a relatively modest list of new features and bug fixes, and I just want to make the code good enough that I can make changes easily when I need to and be reasonably confident that I'm not breaking things.  In other words, I want to do a true refactoring.

If you haven't read Martin Fowler's book, the word "refactoring" is not a synonym for "changing code" or "rewriting code".  Rather, it has a very specific meaning: improving the internal design of code without changing the external behavior.  In other words, all you do is make the code easier to work with - you don't change what it does in any way.  This is why people like Bob Martin tell you that "refactor X" should never be an item in your Scrum backlog.  It is purely a design and "code cleanliness" activity, not a "feature" you can deliver.

So my goal with LnBlog is to gradually reshape it into what it should have been in the first place.  This is partially to make changing it easier in the future.  But more importantly, it's a professional development goal, an exercise in code craftsmanship.  As I mentioned above, I've worked professionally on many systems that are even more messed up than LnBlog.  So this is a study in how to approach refactoring a system.  

And So It Begins...

My intention is to write a number of articles describing this process.  I've already completed the first step, which is rewriting some of the persistence and publication logic.  I'm using the PSP to track my planned and actual performance, so I'll have some actual data to use in my discussion of that process.  Hint: so far, the two are very different.

With any luck, this project will enable me to draw some useful or interesting conclusions about good and bad ways to approach reworking legacy systems.  Maybe it will also enlighten some other people along the way.  And if nothing else, I should at least get a better codebase out of it.