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.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. 


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.

And the current editor is - Vim?

So, as I mentioned before, I'm looking for a new go-to text editor/IDE.  So far, I've taken cursory looks at a few of the options.  These include:

  1. PHPStorm.  As I mentioned in the last post, I use PHPStorm at work.  And while it's really good in a lot of ways, I'm not in love with it.  On the up side, it's got great code intelligence and the VI-mode plugin is actually quite good.  On the down side, it's a single-language IDE (well, not quite, but it's still got a limited set of supported languages).  I guess I could just buy the entire JetBrains IDE suite, but I'm not crazy about switching back and forth.  Also, PHPStorm is kinda heavy - like, Eclipse heavy - both in terms of memory footprint and, more important, conceptual weight of the UI.  So while I don't dislike it, I don't really have any enthusiasm for it.
  2. Visual Studio Code.  I initially liked the look of VS Code.  It's got the cool Visual Studio intellisense, which is nice, and it seems to have a lot of extensions available.  The Vim-emulation plugin seemed fairly good, but not great.  The most popular PHP plugin, however, didn't seem to work out of the box at all.  I'm not sure why, though it could be its wonky install process/implementation (apparently it's written in PHP).  At any rate, I didn't care enough to look into it, though it might be worth taking a closer look at VS Code at some point.
  3. Atom.  I liked the look of Atom.  I read a little about the philosophy behind it and I really wanted to like it.  But then I fired it up and tried opening one of my project directories and it didn't work.  And by "didn't work", I mean that Atom actually crashed, consistently, on this particular directory.  So that's a no-go.  A quick Google revealed that it might be a problem with the Git library, which could possibly be fixed by changing the index version on the repo, but frankly I don't care.  If I can't trust my editor to just open a directory, then I can't trust it at all.  I mean, I don't even care if my editor has Git support at all, so I'm certainly not going to accept crashing if it sees a repo it doesn't like.  
  4. Sublime Text.  I've heard good things about Sublime.  I used to work with several people who really liked it.  Then I fired it up and immediately said, "What the heck is this?"  The UI is pathologically minimal, except for a gajillion menu items and the stupid friggin' mini-map (which I didn't like in Komodo either).  Configuration is done by editing a JSON file, but what the heck is with the weird out-of-box-experience?  The UI is extremely minimal and customization is done by editing a JSON file, which is weird (to be fair, VS Code and Atom do that too, but it's more forgivable because they're free), and the plugin manager was immediately confusing.  Seemed like getting used to Sublime might be a steep learning curve.
  5. Vim.  Yes, you read that right - Vim.  I was surprised too.  Let me explain.

After trying out Sublime, my initial reaction was, "Geez, if I want something that complicated, why don't I just use Vim?"  And then I stopped.  And I said to myself, "Actually...why don't I use Vim?"  Good Vim emulation is one of my must-haves, and no plugin is ever gonna beat the real thing.  It's free, open-source, hugely customizable, has lots of available plugins, and is extremely well established.

The thing is, I knew Vim could be customized into a pseudo-IDE, but I'd never really thought of myself as a hard-core Vim user so I'd never tried it.  But the truth is that I've been a Vim user for a very long time, and for the last few years I've been actively trying to pick up more Vim tricks for use in Vim emulation plugins.  So while I didn't know an awful lot about customizing Vim, I'm very comfortable actually editing code in it.

And it turns out that actually customizing Vim isn't really that bad.  Heck, there are even package managers for Vim now!  There are also IDE-like configuration/plugin bundles you can install, such as spf13, but I quickly determined that those were too big and overwhelming.  However, they are good as a source of ideas and settings to copy into your own custom ~/.vimrc file.  That's actually part of the beauty of Vim - despite the fact that Vim script is a little weird and the configuration is in no way intuitive, there's enough information already out there that it doesn't really matter.

So over the course of a week or so, I pulled out some of the more interesting settings from the spf13 config, found a selection of plugins that I liked, and got myself a nice, functional Vim setup.  I even set up some symlinks and file syncing so that I can have my setup synchronized between home and work.  

Is it perfect?  No, but nothing ever is.  But so far, it's working pretty well.  And what's more, I actually enjoy using it.  It might not have the power of a specialized IDE when it comes to the more advanced features, but it's got a heck of a lot of power in general.  And the amount and types of customization you can do are amazing.  With a little effort, you can really shape the editor to your workflow, which is a thing of beauty.

Looking for a new editor

A couple of weeks ago I started looking into new code editors.  I've been using Komodo for eight or nine years now, counting both KomodoIDE and KomodoEdit, but I'm growing dissatisfied with it.  In fact, I'm becoming unsatisfied enough that I think the time has come to move on.  However, I'm not sure I see an obvious candidate for a replacement.  So in this post, I'll talk about some of the things I find lacking in Komodo and what I'm looking for in an editor.

Why the change?

Let me start by saying that I'm not trying to bad-mouth Komodo here.  I have used it for a long time and it has served me well.  The people at ActiveState are nice and the do good work.  But the direction it seems to be heading in doesn't mesh well with my needs and I'm not sure the cost/benefit analysis of sticking with Komodo makes sense anymore.  Maybe this can provide some insight to the Komodo development team that can help them improve the IDE.

My dissatisfaction started a few months ago, when my team transitioned to a different product.  Unlike the last product we worked on, this one doesn't belong to just us.  This one is core to the company's business, and has several other development teams working on it, not to mention all the other groups that come in contact with it.  As such, there's an existing process and structure that we needed to adhere to, and it quickly became apparent that adhering to that was much easier if you were running the standard development setup, which is PHPStorm on Ubuntu.  I was running KomodoIDE on Windows, so this was a problem.  I was able to use WSL to get around the Linux part, but KomodoIDE just didn't offer the same features that I needed from PHPStorm.

So let's use that as a starting point.  What does PHPStorm offer that Komodo can't compete with at present?  Well, for purposes of the product I'm working on, here's the list:

  1. Code intelligence.  This is by far the biggest factor.  I'm not just talking about intellisense here.  I mean finding and navigating the actual places in the code where a class, function, or method is used or defined.  And not just text search, but actually knowing about the class and its inheritance hierarchy.  PHPStorm is actually pretty awesome at that.  Komodo's code intel., at least least for PHP and JavaScript, is buggy at best and totally broken at worst.  The quality of the experience also seems to vary hugely depending on the codebase you're working with.  It's nice that they have something for code intel., but you can't really rely on it.
  2. Validations.  PHPStorm integrates with phpcs, which is nice because we need to actually adhere to PSR-2.  Komodo doesn't have that built in.  This might seem like a trivial thing because, after all, I can always just run phpcs from the command line.  However, having the check done in the editor is actually hugely useful, because we have a lot of legacy code that doesn't adhere to PSR-2, which makes selectively running the checks for only the code you changed awkward.  Seeing violations in your editor gives you a nice, simple way to catch mistakes you made before they get to code review.
  3. Symfony support.  While it's not built in, PHPStorm has a pretty good quality plugin for Symfony support.  We use Symfony, so this is really nice.  Komodo doesn't have that.

Those things are important, but they are specific to the new product I'm working on.  If these were my only complaints, I would happily continue using Komodo for the foreseeable future and just use PHPStorm for that one project at work.  But they're not.  The list of annoyances and things I don't like has been slowly growing over the years.  This includes actual problems and bugs, missing functionality, and road-map issues (i.e. disagreement with the direction I see Komodo going).  Here's a summary:

  1. Kinda buggy.  I hate to say it, but I've seen a decent amount of weird errors, crashes, and just plain strange behavior in Komodo.  Not a huge number - it certainly hasn't been buggy enough to get switch editors - but it's still a non-trivial issue.  I'll give just a few examples here to give you the flavor of my complaints.
    1. Maybe it's just my perception, but it's rare for the error log or console to not have something in it.
    2. Sometimes when I'm doing things in the "places" panel, some keypress will trigger a change to the next pane of that panel.  I'm not sure what it is and I can't seem to do it on purpose.
    3. I'm constantly empty getting "find" panes accumulating in my bottom panel.  Again, I'm not 100% sure what causes them and can't seem to reproduce intentionally.
    4. I've tried numerous times on numerous versions of Komodo to set up the keybindings for "focus X pane", but they just don't seem to work at all.
    5. There are various places in the settings UI where one setting determines another, but it's not clearly indicated.  So you can change a setting, click OK, and your change will just be ignored because it's invalid, but there's no indication of that.  A good example is the new unit test runner.  For options other than "custom", the testing framework determines which parser is used, but you can still change the parser in the UI.  It just doesn't do anything.
    6. The syntax checking preferences for JavaScript allow you to set a custom JSHint version to use, probably because the integrated one is kind of old.  I've tried this numerous times and have never been able to get it to work.  Oh, and speaking of JSHint, I'm still kinda miffed that Komodo 10 removed the graphical JSHint configuration UI.  Now there's just a text area to enter your settings, so you have to go to the JSHint site and look up the options rather than just being able to pick from a list.
  2. Pretty over functional.  In the last few releases, some of the tools have been revamped in such a way that makes them prettier, but in my opinion doesn't actually make them more useful.  The two big examples that spring to mind are version control and unit testing.
    1. In older versions of Komodo, my only complaint about the VCS integration was that there wasn't an easy way to do a commit of all pending changes in the project - I fixed that myself with a simple macro.  In the new version, they fixed that problem.  But at the same time, the VCS widget no longer displays changes for added files, which is a big pain.  I typically use my VCS diff for pre-commit code review, so it's kind of inconvenient to have to switch to another view to do that.
    2. The new unit test runner in Komodo 10.2 looks very pretty.  However, they removed the key bindings I was using to run the current test suite.  And it didn't detect my old test suites, so I had to recreate them.  They also changed the name-humanizing algorithm, so that test names that used to be rendered nicely in the runner aren't anymore.
  3. Features I don't care about.  It feels like there have been a few of these added lately.  Some of them seem like things that are really just gimmicks that look good in marketing material but either don't provide any value.  Others do provide genuine value, but seem tacked on to pad the feature set, i.e. they're useful, but I don't see the point of having them right in the IDE.  Some examples include:
    1. Collaboration.  You can do real-time editor sharing with someone else using KomodoIDE.  Cool!  And maybe it would be useful if I was doing remote pair programming with someone else who uses Komodo.  But I'm not, so I've never actually used it.  I suppose this could substitute for some of those "social coding" web editors, but this doesn't feel like a general enough use-case to want it integrated into my IDE.
    2. Sharing to kopy.io.  Upload code snippets directly to a code-sharing website.  Nice!  But again, that's something that's not hard to do without IDE support and that I seldom or never do it anyway.  And even if I did, I'd just create  gist on GitHub, not use a new site.
    3. Slack sharing.  You can share code in a Slack channel right from inside Komodo.  Great!  But again, I don't do this often and it's not clear how this is easier than just copy-and-pasting the code into Slack.
    4. Minimap.  A 10,000-foot overview of how your code looks that replaces the traditional scroll bar.  I think Sublime Text had this first.  Sure, it looks really cool, but does anyone actually use these things?  I don't spend a lot of time looking for code segments based on the shape of the text, so it's never been clear to me what useful information this provides.
    5. HTTP inspector.  This is actually an older feature - an HTTP proxy that allows you to inspect traffic.  And it's a genuinely valuable thing for a developer to have.  But you still have to set it up like any other HTTP proxy, so it's not clear how having this baked into the IDE is better than just using a stand-alone proxy app.  And again, this isn't something I need on a regular basis so I've never used it for actual work.
  4. Features that are strange or hard to use.  There are also features that I use, or would like to use, that either don't make sense or don't quite do what I need.  In other words, they could be really good and useful, but the fall short.  For instance:
    1. Keyboard navigation.  Komodo actually has a pretty nice configuration interface for setting up keyboard shortcuts.  Unfortunately, a lot of the actual bindings you might want don't exist (or don't work, as previously noted).  But my big gripe is that navigating around the UI using the keyboard is difficult, particularly in the side/bottom panels.  Trying to navigate between fields within a pane often either doesn't work, gets stuck, switches you to the main editor, or otherwise fails in strange ways.  And as I mentioned earlier, trying to use the keyboard to navigate between different panes seems to just generally not not work.
    2. Regex toolkit.  This seems like a really useful tool.  But I'll be darned if I can figure out how it's supposed to work.  Every now and then I try it and I always spend more time trying to figure out how it works than it would take so just write a one-off test script to test the regex.
    3. Publishing.  Komodo has a publishing tool that lets you push your code up to a remote system for testing.  That's a very nice and useful thing.  Except that it's actually a "synchronizer," by which I mean it only does two-way synchronization of files with a remote server.  Why?  What if I don't care what's on the server and just want to clobber it every time?  That's not such an uncommon occurrence with test servers.  In fact, for me, wanting to pull in changes from the remote servers is distinctly an edge-case, not something I'd want to happen by default.

I could probably go on, but I think I've made my point.  It's not that Komodo is a bad IDE - far from it.  But there are a number of rough edges and niggling little issues that are increasingly starting to bother me.  Choice of editor can be a very personal and subjective thing, and for me it just feels like it's time for a change.

What do I want?

So that leaves the question: what do I want in an editor or IDE?  Well, I'm not completely sure.  I've been using Komodo for a long time, and I do like a lot of things about it.  So let's start with a list of some of those things.  That should at least work as a jumping off point.

  1. Good VI emulation.  I've been using VI emulation in my editors ever since I worked for deviantART.  I got a MacBook Pro when I started there and I found the weird keyboard layout completely infuriating, particularly when I switched back to my regular PC keyboard so I decided to just switch to VI key bindings since they're always the same.  Since then, I've gotten progressively more friendly with VI mode, to the point where coding without it feels strange.  Komodo includes fairly decent VI emulation out of the box, and it's relatively easy to add customizations, so any editor I pick up will need comparable VI emulation support.
  2. Code formatters.  One of the really handy features of Komodo is built-in code formatters.  My most common use-case for this is copying some JSON out of the bowser network monitor, pasting it into Komodo, and formatting it so I can analyze it.  It would be really nice for a new editor to support something like that.
  3. Light-weight.  A concept of "projects" is nice in an IDE, but sometimes I just want to quickly open a file.  So I'd rather not use an IDE that takes ages to start up and insists that everything be part of a project (I'm looking at you, Eclipse).  Komodo is pretty good in that regard - it can just start up and open a file without it being too much of an ordeal.
  4. Extensibility.  No editor or IDE is ever perfect out of the box, so it's important to have a decent extension ecosystem around your editor.  Komodo is pretty good in this regard, with a community site offering a nice assortment of extensions.
  5. Scriptability.  In addition to extensions, one of the things Komodo gets really right is giving you the ability to easily write simple scripts to automate things.  It lets you write user scripts in JavaScript that can be fairly easily hooked into the UI.  This is huge.  There are a lot of "small wins" you can achieve with this kind of scripting that will really improve your workflow.  Supporting extensions is great, but it's hard to justify integrating a feature into your IDE if you need, e.g., an entire Java build environment to write an extension for something you could do in five lines of shell.
  6. Multi-language.  This is a big one.  If you regularly code in more than one language, having to learn a different IDE for each one is a real drag.  In the best-case scenario, you have to configure the same things for each editor.  In the worst-case scenario, you have to learn two completely different tools with completely different features.  Most of my professional work is in PHP and JavaScript these days, but I also do some Python, SQL, BASH and PowerShell scripting, and I'm trying to learn Haskell.  So given the choice, I'd rather learn one editor inside and out than have a bunch of language-specific editors that I use as "notepad with some extra features".
  7. Cross-platform.  Right now I use Windows both at home and at work, but that's not set in stone.  I actually use Windows at work by choice (yeah, yeah, I know) - there are a few people with MacBooks, but most of the other developers use Ubuntu.  /In the past, I've gone back and forth between platforms, so running on Windows, Linux, and MacOS is a hard requirement for me.  I don't want to be tied to one platform or have to learn a different IDE for each if I decide to switch.
  8. The right feel.  This one is highly subjective, but it's important to me that my IDE feel smooth to use.  I want it to work with me, rather than feeling like I have to adapt to it.  This has always been my problem with Eclipse - I feel like the UI doesn't really adapt smoothly to what I want.  Something about coding in it just feels a little "off" to me.

 Time to experiment

So it's time to start doing some experimentation.  It took me a long time to finally settle on Komodo, so I'll probably go back and forth a few times.  

I've got lots of choices, to be sure.  Back when I settled on Komodo Edit, I was looking primarily at free and open-source editors.  My use of Komodo IDE grew out of that.  These days, I'm not as price-sensitive, so commercial IDEs are definitely on the table, provided they have reasonable non-Enterprise pricing (i.e. I'm not gonna spend $2000 on one).

Last time I was IDE shopping I looked at a bunch of Linux-only editors, but those are out.  I used Eclipse for a while, but I'm not inclined to revisit that.  I also used jEdit for a while, and while it was fairly nice, it doesn't appear to be getting much active development these days, and I'm not sure it fits my current requirements anyway.  But now we have things like Sublime Text, Atom, Visual Studio Code and the entire suite of Jet Brains IDEs.  So I've got lots of things to look at.  If nothing else, the process will be good for a few blog posts.

Execution policy weirdness

I discovered something enlightening and annoying this morning: PowerShell uses different execution policy settings for the 32-bit and 64-bit versions.  This is something I did not know and did not expect.

I'd seen this problem before, but could never figure out what was happening.  I'd try to run a command through PowerShell using another program, in this case Vim, and it would fail with the standard error about execution of my profile.ps1 being prohibited by the execution policy setting.  Yet when I bring up Powershell on the command line, everything works and the execution policy looks correct:

PS pgeer> Get-ExecutionPolicy -List Scope ExecutionPolicy ----- --------------- MachinePolicy Undefined UserPolicy Undefined Process Undefined CurrentUser Undefined LocalMachine RemoteSigned

Well, it turns out we're talking about two different versions of Powershell.  When I run it from the terminal, I'm using the 64-bit version.  But my Vim build is 32-bit, which apparently means that it's running the 32-bit version of Powershell.  And that version uses its own execution policy setting.  You can confirm that by explicitly opening "Windows Powershell (x86)" from the start menu and running Get-ExecutionPolicy.  

As for the fix, it's simple: just run Set-ExecutionPolicy RemoteSigned as admin, but do it in both the x86 and x64 versions of Powershell.

As for why Microsoft chose to make the different builds use different execution policies, I couldn't say.  It doesn't make much sense to me.  Although, to be honest, I'm not sure why I even need both versions on the same system.  Maybe to support interop between commandlets and unmanaged code?  Who knows?

KeePass browser plugins

In my last post about KeePass, I mentioned that you can integrate your KeePass password database with your web browser.  In this post, I'll tell you more about how to do that and why it's an extremely handy thing.

Why bother?

So why would you want to bother with integrating your browser with KeePass?  I mean, most browsers have a feature to remember your passwords anyway, so why not just use that?  Or if you want to use KeePass, why not just use that auto-type feature I talked about in the last post?

It's true, you could just use the password manager that's built into your browser.  Pretty much all of them have one, these days.  Most of them will even secure your data with a master password.  They may even synchronize your passwords to the cloud, so you can access them on more than one device.  Granted, that's pretty handy.

However, browser password managers generally just do passwords - they don't allow you to enter extra information or attach files like KeePass does.  They also don't work for things outside the web browser, like for security software such as VPN clients.  So they don't provide you with a single, secure location for all your important account information.  But more importantly, they're generally tied to a single browser.  Sure, Google Chrome can store and synchronize all my passwords, but what if I decide I don't like Chrome anymore?  Maybe I just bought a Mac and decided I really like Safari.  Is there an easy way to get my passwords out of one browser and into another?  I don't know.  

By using KeePass with a plugin for your browser, you can get the best of both worlds.  KeePass itself gives you more power and features than browser password managers and allows keeps you from being tied to a single browser.  Using a browser integration plugin adds on the ability to have the browser automatically fill in your username and password when you visit a website.  It's not quite as convenient as the browser-integrated password managers, but it still pretty good.  And it's definitely a lot easier than trying to use auto-type or copy-and-paste to fill in password forms.

What are my options?

In general, there are a lot of plugins available for KeePass.  Just look at the list.  Or maybe don't - you probably don't care about 90% of those plugins.  The main thing you need to know about is which browsers have plugins available. 

Short answer: Chrome, Firefox, and Safari.

Long answer: Chrome, Firefox, and Safari have proper browser plugins available.  The Chrome plugin also works in Vivaldi and possibly other browsers that are based on Chrome.  There are also form-filling plugins that work with Internet Explorer.  To my knowledge, there is no plugin support available for Microsoft Edge.

For this entry, I'll just talk about setting up a plugin with Chrome.  We're going to use a Chrome extension called ChromeIPass.  It adds a KeePass button to the toolbar in Chrome and can automatically detect login forms on webpages you visit.  It works with a KeePass plugin called KeePassHttp.

First, you need to install the KeePassHttp plugin.  Start by going to the KeePassHttp website and clicking the "download" link, or just download it directly here.  Sadly, KeePass doesn't have a nice way to install plugins - you just have to copy the plugin file to the KeePass plugins folder on your system.  Inconvenient, but fortunately not something you need to do very often.  On most computers, this will be C:\Program Files (x86)\KeePass Password Safe 2\Plugins.  So just copy the KeePassHttp.plgx file that you downloaded and paste it into that location.  Since this is a system directory, you will probably be prompted to grant access.  Click "continue" to copy the file.  Note that if KeePass is running, you will need to close and restart it for it to detect the plugin.

Click "continue" when prompted to allow access to copy the plugin.

Now that the KeePassHttp plugin is installed, KeePass will be able to communicate with Chrome.  You just need to install the ChromeIPass extension.  You can do that by going to the Chrome web store page here and clicking the "Add to Chrome" button.  

So...now what?

OK, now that ChromeIPass is installed, what do you do with it?  Well, not really much until it's time to log into a site.  So pick a site that's in your KeePass database and go there - I'll use sourceforge.net for this example because it's a pretty standard login form.

The first time you try to log into a site using ChromeIPass, you'll need to connect it to your KeePass database.  You should notice a KeePass icon is now in your toolbar.  Make sure KeePass is running and click that button.

You should see a "Connect" button.  Click that and KeePass will prompt you to add a new encryption key for the KeePassHttp plugin.  This is a security mechanism - the KeePassHttp plugin encrypts its communication with your KeePass database and this is just the initial step where it sets that up.  Don't worry about the details right now - just type in a unique name for the key, maybe based on your browser and computer, e.g. "Laptop - Chrome".  You only have to do this the first time you connect a browser to your database - after that, the encryption is automatic.

Now that ChromeIPass is connected to your KeePass database, you can click the ChromeIPass button in your toolbar and click the "Redetect Credetials Fields" to fill in your username and password.  Alternatively, you can just refresh the webpage and they should be auto-filled.  You won't see anything in the browser yet, but KeePass itself ill prompt you to allow access to the password for this site.  You can check the "Remember this decision" box to not be prompted to allow access the next time you visit this site.

(I should probably stop to acknowledge that this thing of having to grant a site access to your KeePass database before you can log in is kind of a drag.  I agree, it is somewhat annoying.  This is actually a security feature of KeePassHttp - that's the portion of this that runs inside KeePass itself and allows the ChromeIPass extension to talk to it.  It actually has a lot of security-related settings.  This is actually a good thing, though, because it essentially provides a way for other programs to read your KeePass database, and you want to make sure that malware or dodgy websites aren't able to do that.  However, if you want to disable some of these settings, like prompting to allow access, you can do that by going into KeePass and selecting the "Tools > KeePassHttp Options" menu item.  The KeePassHttp documentation has some more information on the available settings.)

The good news is that now you're done!  After you allow access to KeePass, ChromeIPass will automatically fill in your username and password.  If you selected the "remember" option when allowing access to the site, ChromeIPass will automatically fill in your login info the next time you visit the site, no action required.  You will only have to allow access the first time you visit a new site of if you elect not to have KeePass remember the approval.

If you're so inclined, ChromeIPass has a number of other features, as detailed in the documentation.  For instance, it can save or update entries automatically when you enter a password into a webpage; it has a built-in password generator that lets you create strong passwords right in the browser; it can customize the login fields for non-standard login forms; and it provides a handy right-click menu to fill in passwords and access other functionality.  

Hopefully this will help get you started.  Using a password manager is a must for keeping your accounts secure these days, and integrated browser support makes using one that much easier, which means you're more likely to keep using it.

Using KeePass

You should be using a password manager.  If you're a technical person, this is probably not news to you - you're very likely already using one.  

This article is for the non-technical people.  People like my wife (hi, honey!) and my mom.  People who access a lot of websites and have a lot of passwords to remember.

Security 101

So why is using a password manager a good idea?

Well, you may have seen guidelines for cyber security that tell you things like:

  1. Don't write down your passwords.
  2. Don't reuse passwords on different sites.
  3. Don't use short, easy to guess passwords.
  4. Don't use passwords that are easy to figure out from public data (like a birthday that anyone can get from your Facebook profile).

Such guidance raises the question: if I have to use long passwords that aren't related to anything in my life, and I can't reuse them or write them down, how the hell am I supposed to remember them?!?

This is a totally reasonable question.  Yes, ideally we would all memorize a hundred different 32-character-long, randomly generated passwords.  But in real life, nobody can actually do that.  So a password manager is a good compromise.

What is a Password Manager

My mother has a little paper "password book" that she keeps in a drawer next to her computer.  When she has to create a new account for some website, she writes down all the login information in that book so that she can look it up later.

A password manager is the digital equivalent of that password book.  It's an application that lets you record your login information and them look it up later.  Most password managers have lots of other handy-dandy features as well, but that's the core of what they do.

So how is this different from, say, writing down all your passwords in a Word document on your desktop?  Well, a password manager encrypts all your data.  It requires a "master password" to decrypt your information, so if some nasty hacker steals that file, they won't be able to actually read it.  

Is this as secure as just memorizing all your passwords?  No.  But as we said, nobody can do that anyway, and this is one heck of a lot more secure than the alternatives, i.e. reused or weak passwords.  With a password manager, you can still have strong, unique passwords for all your sites, but you're relieved of the burden of having to remember them all.

About KeePass

There are a number of password managers out there, but the one I'm going to talk about is KeePass.  It's a free, open-source password management application that will run on Windows, Linux, and Mac, and has compatible apps available for iOS and Android.  KeePass works offline (i.e. it requires no internet connection and doesn't depend on any online services), but it's possible to sync your KeePass passwords between devices using file sync tools like DropBox or OneDrive.  So it provides you some flexibility, but you aren't beholden to a single company that can get hacked or go out of business.

KeePass creates files password files that end with ".kdbx".  You can open those files from within KeePass or double-click on them in Window Explorer.  When you try to open one, KeePass will prompt you for the master password to that file.  Every KDBX file has its own master password.  This allows you to do things like create a password file to share with the rest of your family, and have a different one for the accounts that are just yours.  (That's a topic for a different post.)

One of the handy extra functions of KeePass is that each entry in your password save can have a bunch of extra data associated with it.  For example, you can add custom fields and attach files to each entry, which are handy for things like account validation questions and activation files for software licenses.  Basically, you can keep all the important information in one place.  And since KeePass encrypts your entire password file, it will all be kept secure.

Using KeePass

So how do you use KeePass?  Let's walk through it.

Step 1 - Download

The first thing you need to do is to get yourself a copy of KeePass.  You can go to this page and click the download link for the "professional edition".  (There's not really anything "professional" about it - it's just a newer version with more features.)  When that's done, you can double-click the file to install it like any other program.

You can also install KeePass through Ninite.  If you're not familiar with Ninite, I strongly recommend you check it out.  It's a great tool that makes it brain-dead simple to install and update a collection of programs with just a few clicks.  You basically just select a bunch of applications you'd like to install from a list, click a button, and you get an installer program you can run to put everything you selected on your computer.  And if you run that program again later, it will actually update any of those programs that have a newer version.  It's very slick and a real time-saver.

Step 2 - Create a password safe

 Next, open up KeePass and click "File > New".  You will be prompted to choose where you want to save your new password database.  Choose a name and folder that work for you.  Remember - your password database is just a regular file, so you can always move or rename it later if you want.

After that, you should get a dialog that looks like this:

This shows several options for securing your password safe.  But don't worry about that - the one you really want is the first one, "master password".  So choose a password and type it in.  If you click the three dots on the right, KeePass will display the password as you type, so that you don't have to re-enter it.

There are two important things to note when choosing a master password.  First, since it's going to protect all your other passwords, you want to make it good.  KeePass provides a password strength meter to help you judge, but the main things to bear in mind are that you want a range of different characters and you want it to be long.  And no, ten letters does not qualify as "long" - it should be more of a passphrase than a password.  One common technique is to use a full sentence, complete with capitalization and punctuation (an maybe some numbers, if you can work them in).  That will generally give you a pretty strong password, but it will still be easy to remember.

The other important thing to remember is that the password to a KDBX file is your encription key for that file.  That means that the only way to decrypt the file is with that password.  If you forget your master password, your data is gone forever.  So write down your master password and keep it in a safe place until you're certain you've committed it to memory.  And if you want to change your master password later, make sure to make a backup copy of your KDBX file first.

After you've chosen a master password, you should see a screen that allows you to configure some of the settings for your password file.  However, you don't really need to worry about this - those are all optional.  You can safely click the "OK" button to just continue on.

Step 3 - Organize your passwords

Alright!  You now have a password database set up.  You should see a list of groups on the left and a list of password entries on the right, like in the image below.  These are the sample groups and entries that KeePass creates by default.  They're just to give you an idea of how to use your password database - you can safely delete them at any time.

You can click on each group at the left to see what entries it contains.  The groups are basically like folders in Windows.  There's a top-level folder, and it contains a bunch of sub-folders and each of those sub-folders can contain other folders.  So in the screenshot, you can see that "NewDatabase" is highlighted in the group list.  That's the top-level folder for my example database.  You can see on the right that it contains two entries.  You can move an entry into another folders by dragging it from the entry list on the right onto one of the folders on the left.

Step 4 - Create passwords

To add a password entry to your database, select "Edit > Add Entry" from the menu.  That will bring up the entry edit screen.  This is the same screen you'll see when you double-click on the title of an existing entry, except that it is mostly blank.

There are a lot of tabs and options on this screen, but you don't really need to worry about those.  The main things are right in front of you: the entry title, user name, and password.  You'll probably also want to fill in the URL field with the web address of the site this information is for.  This will come in handy if you want to use a KeePass plugin for your web browser (which we'll cover in another post).  When you're done entering your info, click the OK button to create the entry.  You should then select "File > Save" from the menu or push the "save" button on the toolbar to save the changes to your password database.

You'll probably notice that there's already a password filled in.  KeePass will generate a random password for new entries.  You are free to change this yourself or use the button to the right of the "repeat" box to generate other random passwords using different rules.  KeePass has a password generator that lets you specify the allowed characters and length for a random password, which is handy for those sites that insist on specific password length or complexity rules.

Step 5 - Getting your passwords out

Now let's back up and say you've just started up your computer, are logging in to some website, and want to get a password out of KeePass.  The first thing you need to do is open up your password database.  You can do this by double-clicking on it in Windows Explorer or by opening up KeePass then selecting your database from the "File > Open" menu.  When you open the database, you'll be greeted by a screen asking you to enter your master password - you know, the one you came up with in step 2.  (Hint: remember that you can click the button with the three dots to display the password as you type it.)  After you enter your master password, the database will be decrypted and you'll find yourself and the entry browsing screen from step 3.

There are several ways to get your passwords out of KeePass.  Here's the list in order of preference:

  1. Use a browser plugin to automatically fill in login forms.  Since most of the passwords you end up creating are for websites, setting up your browser to fill in the forms from your KeePass database makes life much easier.  I'll talk about how to do that in the next post.  But don't worry - it's not all that hard.
  2. Use auto-type.  This is a feature of KeePass where you to click a button in the KeePass window and it will automatically send the keystrokes for your username and password to the last window you used.  So, for example, you would navigate to the login page of a site in your web browser, click in the username box, and then switch over to the KeePass window and click the auto-type button on the toolbar (the one that looks kind of like some keyboard keys - hover your cursor over the buttons to see the descriptions).  By default, the auto-type feature will type your username, the "tab" key, your password, and then the "enter" key.  This will work for probably 90% or more of login pages, but it's not universal, so be aware of that.
  3. Copy them to the clipboard.  If all else fails, you can always just copy your passwords to the clipboard so that you can paste them into another window.  KeePass makes this fairly easy.  In the main password list that you saw in step 3, when you double-click on the actual username or password for an entry in the list, it will copy that to the clipboard.  This saves you having to open up the entry edit screen and copy things there.  You can then switch to another window and paste the data into a login screen.
  4. Just read it.  Last, but not least, you can always go low-tech and just read the passwords out of the window.  Just double-click the name of your entry, then click the "three dots" button to make the password visible.  Clearly this is not great, but sometimes it's necessary.  For example, you will need to do this when entering a password on a system that doesn't have KeePass installed, such as to login into your Amazon or Netflix account when setting up a Roku or other streaming media system.


With any luck, I've made this "password manager" thing sound good enough for you to try it out.  You really should look into it.  Password reuse has become increasingly dangerous, with hackers trying the usernames and passwords they harvested from one hack on other sites just to see if they work.  Password cracking tools have also advanced a lot in recent years, including information gleaned from previous attacks, so relying on things like "133t 5p34k" passwords is no longer good enough.  A decent password manager, if used consistently with randomly generated passwords, will provide you with a good trade-off between convenience and security.

Powershell version of "which" command

As yet another note to myself (because I keep having to look this up), the equivalent of the UNIX which command in PowerShell is Get-Command.  That commandlet will let you pass in a name, with no extension, and return you the executable in your path that corresponds to that name.  This is really handy because it works with any executable, including native binaries and batch and PowerShell scripts.  So, for example:

PS pgeer> Get-Command rsync

CommandType     Name                 Version    Source
-----------     ----                 -------    ------
Application     rsync.cmd      C:\Users\pgeer\bin\rsync.cmd

The point of estimates

The other day I listened to a very interesting talk by Allen Holub on the #NoEstimates movement, which I've posted about before.  It's definitely worth a look if you have some time.  Mr. Holub makes the slightly controversial claim that all estimates are evil and we should all just stop doing them immediately.  His rationale for this is essentially that estimates are made up and harmful.  And, of course, he's not wrong.

I've always been a little skeptical of the #NoEstimates movement, but the thing it clearly get right is that estimates are frequently misused and misapplied.  Just about every developer has a story about estimates being interpreted as promises, or having to work late just to "meet your sprint commitments", or skimping on quality because the sprint is about to end and you need to close out your tasks.  And we won't even get into managers who try to use estimates as a performance evaluation tool - the dysfunction of this should be obvious to anyone with any experience.

Is it the estimates?

So estimates can be used for bad things.  That's not controversial.  But that's also not a problem with estimation per se.  I guess you could think of it as the software equivalent of "guns don't kill people, people kill people."  It's not that estimates are inherently bad, it's just that they're seldom used for good.  That doesn't mean that you should abolish estimates, but it does mean that you should use them with caution.

The thing about estimates is that, while they're often just guesses, they don't have to be.  In my study of the Personal Software Process (PSP), I learned about doing estimates based on historical data.  I've even seen it work - in my last job, I reached the point where my time estimates were within about 15% of actual task completion time, which I consider to be pretty good given that the estimates were in minutes.  Granted, it doesn't always work - sometimes you have tasks that are truly unprecedented or have too many unknowns - but it can be done.

The main problem with data-based estimation is that most organizations and developers are not equipped to do it.  For one thing, it requires data, and a lot of shops don't actually collect the kind of data that would be useful.  Most developers certainly don't collect the kind of data that the PSP estimation method uses.  It also takes more time than many people seem to want to devote to estimates.  It's not that much time, but still a lot longer than saying, "well, I guess that's about eight story points".

What's the point?

The real question here is: why do you want an estimate?  What are you trying to accomplish?

When I do PSP estimates, I'm using them to gauge my performance.  I'm looking at my historical data and using that to project out time, code volume, and defect counts.  I can compare these projections to my actual results, see if my performance is consistent, and if not, analyze the reasons and look for ways to improve in the future.

Yes, these are "estimates", but not in the same sense as most teams do them.  My manager never sees these "estimates"; I make no commitments based on them; nobody depends on their being accurate; in fact, nobody but me even knows what they are.  They're a part of my task planning, so they're short-term estimates - they go out two or three weeks at most, usually more like a few days.  I start with some requirements analysis, sketch out a conceptual design, and then do the estimate based on that.  So the process of coming up with the estimate actually helps me flesh out and validate my plan, which is valuable in and of itself.

The important thing to note in the above description is that my estimates are not targets.  If I'm working on a task and it takes 500% longer than my estimate, I'm the only one who knows and I don't care.  Sure, I'll try to figure out why that task took so much longer than I thought, but the fact that "I missed my estimates" has no relevance and no consequences.

But that's usually not how it works when your boss or your project manager (or even your scrum master) asks you for an estimate.  They want you to tell them when the task will be done.  And they'll be very disappointed if it's not done when you said it would be.  And that's where the dysfunction begins....  Because even in the best of circumstances, we don't really know exactly how long s development task will take.  And we seldom work in the best of circumstances.

So...no estimates?

The interesting thing about doing PSP estimates is that, until relatively recently, I had trouble not thinking of the estimates as targets.  Process Dashboard, my PSP support tool, has a progress bar that counts down the time remaining for your estimate and then turns red when you go over the estimate.  And I would actually get upset when that bar turned red!  Why?!?  There was no reason for that - there was literally nothing at stake!  I was just psychologically stuck in the wrong mindset.  And that's the same mindset that most people get stuck in when they talk about estimates.

So I'm starting to come around to this "no estimates" thing.  I still believe that estimates can be useful and productive, but they usually aren't.  And if your company is particularly enlightened and can do estimates in a way that's productive and avoids the pathological effects associated with them, then by all means, keep doing estimates.  But most people don't work in companies like that.  And even if your company is great, you still need to be careful of the psychological pressure created by the inherent biases and preconceptions of your developers.

In other words, estimate carefully.  Consider simpler, lower precision (but not necessarily lower accuracy) methods like Mr. Holub and the other #NoEstimates advocates describe.  Don't be fooled - those are still estimates, but they at least make an effort to work around the damaging side-effects associated with traditional estimation.  After all, it doesn't matter how good the estimates are if they destroy team morale.

TDD...it works?

For the last six months or so, I've spent a lot of time reading about the SOLID principles and listening to lectures about agile development practices by the likes of Bob Martin, Dave Thomas, and Martin Fowler.  The result has been a new and different understanding of what "agile" really means.

One of the agile practices I've really warmed up to is test-driven development. Uncle Bob advocates very strongly for it, and it was one of his talks that got me to finally try it again.  I'm too lazy to find the exact quote, but it was something like:

What if you had a button on your keyboard that you could press and it would tell you if your code was working?  How would that change your life?  Test driven development gives you that button.

Of course, that's a bit hyperbolic, but the point still stands.  The idea that you could have a tool that could tell you, "yup, this code works as intended" is really powerful.  Even if building such a tool is a lot of work, it seems like it would be worth it.

But the thing is, I've tried TDD before.  In fact, I've tried it for about a week or so every year for about the last five years.  And you know what?  It never really worked for me.  It was awkward, the tests were brittle and hard to read, and it just didn't seem to help me much at all.  I came away thinking that it was a stupid fad that didn't help and didn't really make sense. 

But things were different this time.  I'd spent months immersing myself in the SOLID principles, object-oriented design, and techniques for writing good tests.  This time I was ready.  It turns out that knowing how to structure your code and your tests makes the entire process infinitely smoother and simpler.  Heck, it's even kind of fun.

TDD Results

So how did it go this time?  Well, I'd say it was fairly successful.  I've been able to actually use TDD and stick with it without feeling like I was wasting my time.  That alone is a big improvement from my previous attempts.  But I can go deeper than that.  Thanks to the data I've collected using the PSP, I can actually do some analysis of just how well TDD is working for me.

About the Process

Before getting into the details, let's talk about what my process looked like before and what it looks like now.  That will help give some context to the numbers and make it more obvious why they look the way they do.

My process is based on the (now deprecated) PSP 3.  For each task, I start with a quick high-level design sketch, and then one or more development cycles, each of which consist of design, design review, code, code review, and then test.  The "design" phase consisted of conventional design and some skeleton coding (defining interfaces, defining UI components, outlining algorithms, etc.), the "code" phase consisted of fleshing out those outlines and implementing the rest of the design, and the "test" phase was writing unit tests followed by manual system-level testing.

The new TDD-based process changes that a bit.  The "design" phase is very similar, but I've been going into less detail in the algorithms involved.  The idea was to let the detailed design "emerge" in the process of writing tests, though I've started moving away from that a little.  The "code" phase is now a series of TDD cycles.  That means that it encompasses both actual coding and unit testing.  The "test" phase has become just manual testing.  I did this because, realistically, trying to track test vs. code time when I'm switching back and forth every few minutes was going to be tedious and error prone and I didn't want to do it. 

Unfortunately, this makes the analysis much harder because we're not comparing apples to apples.  Both processes did try to achieve comprehensive unit test coverage, so they're not completely incomparable, but the change in definition of the "testing" and "coding" phases does make certain comparisons moot.

About the Data

I've been collecting PSP data on the coding tasks I've had over the last six months at my current job.  Currently I have 25 data points - 15 using the old process and 10 using TDD.  The data is collected on a per-task basis, and the task sizes vary wildly, from about an hour and a couple dozen lines of code, to two weeks and a couple thousand lines of code.  The tasks are all webdev work and include a combination of back-end PHP, front-end functionality in JavaScript, and HTML/CSS display stuff in varying proportions.

Of course, the variety in the individual tasks undermines the data a bit, but that can't really be helped.  I'm just working with the tasks I'm given - I don't have the time to do a genuinely scientific comparison.I mean, I do actually need to get some work done at some point - I'm not getting paid to analyze my own performance.  

The Results - Summary

Overall, the TDD-based process seems to be working as well as, if not better than, what I'll call the "conventional" process.  Below is a summary table of overall metrics:

Summary Plan (TDD) Actual (TDD) Plan (Conv.) Actual (Conv.)
LOC/Hour 53.2 58.4 38.4 48.9
Total Time 73:18:00 107:41:00 84:32:00 102:30:00
Total New & Changed LOC 3903 6290 3249 5017
Test Defects/KLOC 21.3 15.3 14.4 26.7
Total Defects/KLOC 53.1 39.4 65.4 58.6
Yield %
55.90% 61.00% 59.00% 54.20%
% Appraisal COQ 16.00% 15.30% 16.40% 16.20%
% Failure COQ 32.30% 15.30% 34.00% 38.00%
PSP summary data for TDD vs. conventional process.
Definitions: Yield % = percentage of defects removed before testing, % Appraisal COQ = percentage of time spent on review activities, % Failure COQ = percentage of time spent in testing.

For the two data sets, the total time and code volume were substantial and in the same neighborhood, so the data sets are at least comparable.  We can see the TDD data shows higher productivity (in LOC/hour), fewer defects, better review yield, and lower cost of quality. 

So this means that TDD is definitively better, right?

Well...no.  The change in definition of the "code" phase means that I'm logging fewer defects in general.  Part of my defect standard is that I don't record a defect if it's introduced in the same phase where it's fixed.  So with TDD, little things like typos and obvious logic errors are caught by unit tests in the code phase, so they don't show up at all in these numbers.  In the conventional process, they wouldn't have been picked up until code review or testing.  The same reasoning applies to the failure cost-of-quality - since writing unit tests is now part of the code phase rather than the test phase, less time would naturally be spent in testing because there's simply less work that needs to be done in that phase now.

However, the productivity difference is still interesting, as is the improvement in percent yield. Those do suggest that there's some improvement from using TDD.

Drilling Down - Time

So since the change in phase definition makes defect numbers incomparable, let's look at time data instead.  This table shows the percentage of time spent in each phase.

Phase Actual % (TDD) Actual % (Conv.)
  Planning 3.08% 4.60%
  High-level Design 1.42% 1.59%
  High-level Design Review 0.87% 1.04%
  Detailed Design 8.05% 12.30%
  Detailed Design Review 4.27% 4.59%
  Code 51.90% 22.10%
  Code Review 10.20% 10.50%
  Test 15.30% 38.00%
  Postmortem 4.91% 5.35%
Percentage of time by phase.

 The results here are largely unsurprising.  The percentages are roughly equivalent for most of the phases, with the notable exceptions of code and test. 

However, it is interesting to note that there's still a discrepancy between the total code+test time for the two processes.  Theoretically, based on the phase definitions, that combination should encompass the same work for both processes.  But the TDD process spent 67.2% of the time on coding and testing, but it was only 50.1% for the conventional process.  It appears that the single largest chunk of that disparity comes out of design time.  This makes sense because there was less detailed design in the TDD process.

Note that the review times were roughly equivalent for each process - in fact, they were slightly lower with TDD.  Yet the percent yield for reviews was higher with TDD.  This gives us some evidence that the difference in percent yield can be attributed is likely due to the use of TDD.

It's not entirely clear why this would be the case.  The most obvious outcome would be lower yield, as the use of TDD means that fewer bugs escape to be found.  My working hypothesis, however, is that using TDD lowers the cognitive load of code review by removing most of the noise.  With TDD, you already know the code works.  You don't have to review for things like typos, syntax errors, or misused functions because you've already tested for those things.  That leaves you more time and energy to dig into more substantive issues of design, requirements coverage, and usability.

Back to Defects

Hmm....  Maybe we should take another look at the defect data after all.  We've already established that number of defects isn't going to be useful due to the change in phase definition.  But what about average fix times?  If TDD is weeding out the simpler bugs so that they don't escape the coding phase and don't get recorded, we'd expect the average fix time to be higher.

    Found in test (TDD) Found in other phases (TDD) Total defects found (TDD) Found in test (Conv.) Found in other phases (Conv.) Total defects found (Conv.)
Injected in HLD Tot. fix time - 28.4 28.4 - 18.2 18.2
Tot. defects - 9 9 - 13 13
Avg. fix time - 3.16 3.16 - 1.4 1.4
Injected in Design Tot. fix time 448.4 321 769.4 271.1 241.6 512.7
Tot. defects 48 57 105 51 63 114
Avg. fix time 9.34 5.63 7.33 5.32 3.83 4.5
Injected in Code Tot. fix time 223.2 293.3 516.5 341.6 230.4 572
Tot. defects 39 91 130 78 84 162
Avg. fix time 5.72 3.22 3.97 4.38 2.74 3.53
Total Injected Tot. fix time 724.9 647.1 1372 629.3 500.1 1129.4
Tot. defects 96 160 256 134 165 299
Avg. fix time 7.55 4.04 5.36 4.7 3.03 3.78
Defect count and fix time (in minutes) by injection phase.

The above table shows the break-down of defect count and fix time by injection phase.  So what does this tell us?  Well, my hypothesis that TDD would produce higher average fix times seems to be correct.  If we look at the fix times for defects injected in code and found in test, the average fix time is about 30% higher. 

However, it's worth noting that the TDD data has higher average fix times across the board.  It's not entirely clear why this should be.  One possible explanation is that the use of TDD means that unit tests are introduced earlier in the process, so defects fixed in code and code review would require changes to the test suite, whereas in the conventional process that would only happen for defects found in test.  That's something I'll have to watch in the future.


So far, my new TDD-based process seems to be working out pretty well.  The results are somewhat ambiguous, but the numbers suggest that TDD is resulting in higher LOC/hour productivity and more efficient defect removal. 

From a more human perspective, it has the benefit of making unit testing much less tedious and painful.  It gets you earlier feedback on whether your code is working and gives a nice sense of satisfaction as you watch that list of test cases grow.

But ore importantly, TDD is a great way to test your test cases.  When you're writing your unit tests after the fact, it's very easy to get stuck in a situation where a test is unexpectedly failing (or, worse, passing) and you can't tell whether the problem is with your test case or the code under test.  With TDD, you're changing things in very small increments, so it's easier to pinpoint the source of problems like that.

But the big lesson here is that TDD isn't something you can just jump into.  You have to understand the context and the design techniques first.  If you do, then it's pretty great.  If not, then you're going to have a hard time and end up wondering who came up with this hair-brained idea.