Tag Archives: code

Software and Chicken Entrails

Posted by David Brady on August 10, 2011 None comments
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I had a collection of epiphanies today about Informational Software.

“Informational Software” is a term I use to describe software that helps you understand and make decisions about information. It is not a product and does not make your business money, but it can be used to help you understand your business and therefore, in theory, help you make money. For example, analytics software does not make you money, but you can use it to understand your traffic and hopefully to then minimize your costs and maximize your revenues. (Note that if you are selling an analytics package, this definition is still true, because in that case the software is a product, not an information tool*.)

Informational Software comes in two types: software that interprets trends and data and makes decisions for the user, and software that collects and reveals data so the user can make their own decisions. Expert systems are an example of the former, analytics packages are an example of the latter.

Let’s call this mess of data the chicken entrails. We want to read them and predict the future, right? Sure we do. That’s what chicken entrails are for.

Okay, enough definition. Here are the epiphanies:

First: If your users are untrained and the data is simple, your system can advise the user and/or make decisions for them. If they cannot read the entrails, or the entrails are too simple to bother the entrail readers, do not let/make them read the entrails.

Second: (Pay attention, this is the important bit) If your users are highly trained and the data is very complex, do not attempt to interpret the entrails for them. Just show them the entrails. Highly trained users who have asked you for information software do not want you to do their job, they want a tool to help them do their job better.

Third: My instinct is always write software that interprets entrails, regardless of the complexity and regardless of user knowledge. Learn to stop and figure out what it really needed.

Fourth: Interpreting complex data is really, really hard. On a small, knock-it-out project, it is almost certainly doomed to fail. Now reread the 2nd epiphany: On small, knock-em-out projects, it is completely unnecessary.

Right now I’m working on software that reveals entrails to some truly arcane masters of entrail reading. They have become masters because the information system currently available to them is literally designed to protect the data from their eyes. I have found two pieces of data, correlated them, and put them into a report, and they think I’m a super genius. Not because my software is smart, but because it is smart enough to be dumb.

I really like epiphanies where I suddenly realize that it is not necessary to be doomed to failure.

* And if you’re smart enough to reason “but what if you’re using your analytics tool to analyze the sales of your analytics tool”, I congratulate you on your cleverness. Can you also see the flaw in this reasoning?

Two Questions

Posted by David Brady on July 27, 2011 3 comments
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Recently I was talking with a friend about coaching and specifically the act of helping younger developers improve themselves. I had a sort of microepiphany when I realized that I’ve been improving myself for over two decades with the same pair of questions, originally unconsciously and only recently in my active consciousness. The next time you do something you want to get better at, ask yourself these two questions:

What about this makes me feel good? This is a VERY specific question, and it is NOT “what do I like about this?”. It’s often hard to answer. You are not allowed to say “I don’t know”, and you are not allowed to settle for answering the much easier question “what about this do I like?”—although that can be a great guide into discovering what it is that makes you feel good. If you wrote an elegant passage of code, or did something clever, or shipped a really nasty hack but saved the company (thus buying them time to refactor your nasty hack) by shipping on time, that’s what you like. But go beyond this. What about that makes you feel good? Did it make you feel smart? Did it make you feel artistic? Did it make you feel like a hero? Did it make you feel like somehow, against all the odds, you might just be starting to “get it” as a programmer?

Take a moment and really just let yourself feel good about what you did. If you can find that and tap into it, you have just found a well inside yourself that you will return to again and again in the future. Congratulations, you’ve just found the reason you’re going to spend the rest of your life getting better at this.

If you can’t answer this question, don’t sweat it. But don’t be surprised if your life ends up going a different direction. Find something else that makes you feel good, and do that instead.

What about this could I do better? Most days, you’ll think of something right off. There was some duplication, or a lack of symmetry in the code, or your variable names were kind of awkward.

Other days it’s a bit harder. “Writing this bit felt a bit grindy, like I was pushing out lots of boilerplate. I don’t see how to fix it, but does it really have to hurt this much?”

The best days are the days when you try and try and just can’t answer it. Important: this doesn’t mean you did something perfect. Far from it, and far better: it means you’ve actually managed to see your blind spot. “This”, your brain is telling you, “this empty space, here… is where more knowledge will fit.” Those are the days that herald “getting it” on a whole new level.

So, them’s my questions for you. What made you feel good? What could do better?

Felt any good or done any better recently?

Donkeypunching Ruby Koans

Posted by David Brady on July 27, 2011 3 comments
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Do you want instant enlightenment? Sure, we all do.

And now you can have it!

Tonight I presented Ruby Koans at URUG. It started out simple enough, but then we got on a weird quirk about trying to make the Koan tests pass without actually satisfying the test requirements. We monkeypatched Fixnum, then started playing with patching Object#to_s… basically we were looking for TMAETTCPW: The Most AEvil Thing That Could Possibly Work. I spelled Evil AEvil because it’s extra evilly.

Mike Moore had the bright idea to just break off all the assert methods in Test::Unit; after that it just became a challenge to discover how to get the rest of the koans to run at all.

With sincere apologies to Matz, Jim and Joe, here is the result:

https://gist.github.com/1108850

Tourbus 2 is Out!

Posted by David Brady on May 4, 2011 1 comments
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I just released Tourbus 2.0! You can get it by cloning the tourbus repo in that link, or by simply installing the gem from rubyforge.

What’s TourBus?

TourBus is a ruby framework for stress-testing a website. You define “Tourist” classes that “tour” their way through your site, and then tell tourbus to send a load of them at your site.

What’s New

Better Syntax, and tested support for most rubies. TourBus 2.0 has been tested and found worky on:

  • JRuby 1.6.0 <– strongly recommended, as it has better threading
  • MRI 1.8.7p334
  • MRI 1.9.2p180
  • REE 1.8.7-2011.03

Upgrading from Tourbus 0.9

  • Your tour classes will change; they are now called tourists and they go on tours, instead of being called tours who run tests (which really never made sense anyway)
  • Open your tour class, and change it to inherit from Tourist instead of Tour.
  • Change before_tests and after_tests to before_tours and after_tours.
  • Rename all your test_ methods to be tour_ methods. E.g. “def test_simple” => “def tour_simple”
  • That’s it! Tourbus should now run normally.

Quick and Easy Setup

gem install tourbus

Okay, let’s say you have a website running at localhost:3000 and you want to test that home.html includes the text “hi there” even when being pounded by hundreds of visitors at once. Let’s install and set up everything all at once! cd into your project folder, and do the following:

mkdir tours
 
echo 'class Simple < Tourist
  def tour_home
    visit "http://localhost:3000/home.html"
    assert_contain "hi there"
    end
end' > tours/simple.rb

That’s it, you now have a tourist ready to wander over to your site and request the home page. Let’s run him and see that everything’s okay:

tourbus

You should see a clean run followed by a text report showing what happened. If that worked, let’s make your tourist go through the website 10 times in a row. But let’s ALSO make 100 different tourists to the same 10 laps with him, all at once:

tourbus -n 10 -c 100

Happy server stressing! Check out the README for more info.

Bonus: Isolating Tourbus

Here’s how I like to install tourbus. I cd into my development folder, and then do:
rvm install jruby-1.6.0
rvm use jruby-1.6.0
rvm gemset create tourbus
rvm gemset use tourbus
git clone git://github.com/dbrady/tourbus.git
cd tourbus
gem install bundler
bundle install
gem build tourbus.gemspec
gem install tourbus-2.0.1.gem # (update version if it changes)

Next I cd into my project and do

echo 'rvm use jruby-1.6.0@tourbus' > .rvmrc

This lets me run tourbus under jruby and its own gemset, so even if my website is running rails on MRI, I can still get the lovely JVM native threads when tourbussing my site.

James Edward Gray: Associative Arrays and Ruby Hashes

Posted by David Brady on April 6, 2011 14 comments
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Yesterday I put out a little screencast showing some ways of Creating Ruby Hashes. James Edward Gray II pinged me on Twitter and basically said “Great screencast! Ooh, but you forgot this! Ooh, and this! And this!” and so of course there was nothing to do for it but invite him to do a pairing screencast with me.

This video is a bit of a weird hybrid. You get 7 minutes of podcall, then 18 minutes of screencast, then another 12 minutes of podcall. James shows off some of the “hot new awesomeness” of Ruby 1.9, and then points out that this awesomeness has been around for a couple of years and nobody’s using it, in spite of it having been in the current Pickaxe for nearly as long. Along the way we talk about regular expressions, testing dogma, and the importance of never squashing creativity in the open source community. All in all, an incredibly fun time for me. James threatened to come back and do another one with me on regular expressions, and I’m mentioning it here in writing so that everybody knows I plan on taking him up on that offer.

No podcast, because half of it is us typing into a shared screen session. But here’s the video. You may need to watch it on Vimeo or download it to see the font clearly.

Associative Arrays with James Edward Gray II from David Brady on Vimeo.

Creating Ruby Hashes

Posted by David Brady on April 5, 2011 23 comments
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I just created a quick Ruby screencast on creating hashes. I don’t cover all of the possibilities, but I do show 5 ways—including one you should never use. Let me know what you think, and if you have questions or ideas for a future screencast, chime in!

Ruby Hashes from David Brady on Vimeo.

SVN Users: Why You Should Switch To Git

Posted by David Brady on March 27, 2011 14 comments
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Recently a coworker of mine told me he was happy with SVN, and had been for years. Why should he and his team switch to git if they were productive and happy? I posted this to our internal message board, but I think the answer is broad enough to merit posting here on my blog. Enjoy. Which vcs do you use, and why do you like it? Are there any ex-git users out there who prefer something else?

Just my $0.02, but I hear this concern from satisfied svn users a lot. I used to be one myself. There is a compelling answer, but unfortunately I don’t know how to articulate it. Almost without exception, every svn user I have seen switch to git has slapped their forehead and said, “My goodness, why didn’t you tell me the world wasn’t flat?!?”

I think the problem is threefold. First, git was very hard to use when it first came out, which turned a lot of people off. Second, it was kind of a hipster trendy thing, which turned even more people off. But most importantly, every advantage that git provides over svn is something that svn users have learned to live without, and so when you say “git can do this”, svn users say “Yeah, but we don’t need or use that.”

You need those things. They will make you happy. Take it on faith until you begin to enjoy the fruits yourself. :-) Git offers a ton of incredible things over svn. I’ll mention just my top three favorites.

First, you can branch in git, and you don’t do that in svn. I know what you’re thinking: you CAN branch in svn. That’s not what I said. I said you DON’T. Because it’s such a pain to do and merging is such a nightmare, I’ve only ever met one team that used branching heavily in svn. They were a company with 500+ developers, however, and had IT staff on hand full-time to enforce the engineering discipline to keep their branches under control, and once a week the dev team stopped and had a “merge day” when branches were folded back into the mainline. In contrast, git’s merging tools are so freakishly powerful that branching becomes nearly a zero-cost operation. In the past week, I have created or worked in not less than ten different branches across three projects. Each feature, each bugfix, isolated in its own branch. All of the code is changed and updated, and pushed up to the server. Some of the branches were merged immediately, some are still awaiting QA testing before it can be deployed. So that’s feature number one: Git makes branching and merging so easy that you’ll use it all the time.

Second, and this is a huge implication, because branching and merging are so easy, you no longer have this problem where everybody is syncing and merging with trunk, where every feature change gets deployed to production as soon as you finish it. You might be tempted to lump this in with my first point, but as somebody who occasionally gets dragged back into svn from git, this is totally a separate concern. You can’t do exploratory branches easily, so you don’t do them. With git, you can fork a branch, make some changes, forget about the branch, go back and work in master (git’s word for “trunk”) for a month, then come back to your exploratory branch and type “rebase” and it will MOVE your changes forward in time, updating the trunk and then “playing your changes back” over the new trunk, making it as though you had forked yesterday instead of a month ago. If you’ve ever made a bugfix and then had to hold off pushing your commit because QA was still testing trunk for a deploy, you need to switch to git.

Thirdly, git is distributed. Everybody gets the obvious implication of this, that you could be pushing your code to multiple servers. And big deal, right? You could be backing up your svn repo just as easily. But everybody misses the subtle implications of this, which are earth-shattering: one, what you call your sandbox, git consider to be just another repo. Which means you can be on a plane with no internet access, and you can checkout old revisions, commit code to a feature branch, fix a bug in master, and start two new exploratory branches, all without being connected to the main repo. What svn calls a commit, git calls a push, and it syncs your “local” repo with the remote one. (What git calls a commit is just storing a change from your sandbox to your local repo database to be pushed later.) And two, because you have a full copy of the local repo in your sandbox, you can play amazing games with the commit history. Checked in a file you shouldn’t have? Go back into your repo’s history and remove it from the commit stream before you push it to the server. Wrote the wrong bug number on your checkin? Amend your commit message. Pulled down latest code only to discover that 12 files are in conflict and you just want the version from two days ago? You can jump over to that commit and grab them.

That’s my $0.02, which I guess on a per-word basis appears to be quite the bargain. Sorry. TL;DR: git takes your version control game to a whole new level that you didn’t even know existed. If you’re happy with svn, you don’t NEED to use git. But if you want to STAY happy with svn, trust me: don’t ever switch. You WON’T be able to go back.

(Well, actually, you will. git has a svn emulation module that lets you have a git repo locally and push commits to a svn server. It still has the problem of “the dev team are all committing to trunk”, but features 1 and 3, of branching and distributing, still shine through. It makes working with subversion… bearable.)

Yes You Should Test Private Methods (Sometimes)

Posted by David Brady on December 4, 2010 None comments
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Lasse Koskela recently wrote Test Everything, But Not Private Methods on his blog. Thank you for writing this, Lasse. This is one of the most intelligent, albeit still wrong, posts I’ve read on the topic. Lasse specifically addresses one of my greatest concerns, which is simply that “if it can possibly break, it should be tested.”

It turns out that on the face, we are in agreement: you should not leave complicated code untested. Lasse’s answer (which is repeated by several folks, including Michael Feathers and Mike Bria) is simply to not write complicated private methods. If you have a complicated private method, you should make it public and test it. If it doesn’t belong on the public interface of the class, then move it to another class or create a new one where it can be public. As Michael Feathers puts it in his book Working With Legacy Code: “the real answer is that if you have the urge to test a private method, the method shouldn’t be private; if making the method public bothers you, chances are, it is because it is part of a separate responsibility: it should be on another class.”

I’m a huge fan of Michael Feathers, bordering on Fanboy lunacy, so I’m a bit hesitant to disagree with him. Also, to be fair, I agree with Lasse one hundred percent–about 90% of the time. However, Mike and Lasse present “extract method to class” as a panacea when it is in itself merely a tradeoff with serious consequences of its own.

Extracting a class dilutes and adds complexity to your namespace. Code should struggle very hard to earn a spot at this level. I spend a lot of mental energy on a project trying to understand the class hierarchy, so much so that it is worth my effort to spent time trying to keep it well-organized to assist this understanding. A method that was meant to be private and to serve a class at a specific point in time suddenly becomes a public object. Care must be taken to either make the new class generic enough and provably safe to be used by arbitrary clients, or to prevent other classes from accessing the class at all. If you find yourself trying to figure out how to control access to the class, chances are the code you are trying to extract really should be private after all.

If you are going to extract the private method to a class, considerable care should be taken that it does not, in fact, still fall under the responsibility of the class that contained it. If your new class ends up with an “-er” name, especially “-Manager” or “-Controller”, it’s probably just a Functor–a method call masquerading as an object. If the moved method has many side effects, especially ones that modify instance variables, the moved method will end up taking many arguments and returning many values that the original class must then use to modify itself. You may just end up passing in the original class to the method. Now what you’ve done is replaced the “this” keyword with a variable named “that”. This is a code smell; it’s called Feature Envy, and the solution is to move the method into the envied class. If the new class has the original class’s name in its own, you’ve all but conceded that the new class is useless in isolation from its progenitor; all you’ve really accomplished in this case is cluttering up the object namespace in order to achieve one outcome: making the private method testable. Lasse eschews inelegant workarounds like reflection nonsense or package hackery, but complicating the object map is just as inelegant if it achieves nothing more than making a private method public.

Another counterargument is–and though this is a situation that I wish did not actually exist, every developer has in fact faced it–extract class is not a free refactoring, and on large legacy projects it may be prohibitively expensive. Suddenly “change the design” becomes “they shouldn’t have designed it that way in the first place” and the only solution is to invent a time machine, go back in time, and not have done it wrong. This isn’t practical.

Sometimes you have a method that is, and should be, both private and complex enough to require testing. When that happens, you should test it.

I agree with Lasse and Mike about the problems inherent with testing private methods; I just don’t think their proposed solution is always workable.

This post is getting long, so I’m going to breaak it into to two separate entries. Next up: I want to present some cases when I think I should, even using TDD, design and write private methods that should be tested. I’m also going to address what I think is the primary concern of anti-private-testers, that testing private methods is testing implementation. (Teaser: I completely agree–but I hope to show you why, in some cases, that’s not a problem or at least an acceptable tradeoff.)

Intelligence and Prediction

Posted by David Brady on September 25, 2010 None comments
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Cleaning my office today, I found a sheet of paper covered in my own handwriting. I had been somewhere without my journal when an epiphany had struck. I’m cleaning office now, and didn’t want to throw it away. Here it is for posterity, such as that may be.

One measure of intelligence is the ability to take a set of observations at varying degrees of confidence and accurately predict outcomes. The greater the intelligence, experience, and capacity for reason, the more detailed the predictions become, the more distant they can be and the fewer and less confident the observations upon which they are based.

When I was the Director of Technology at RESMARK, the president was my good friend and we would spent long hours planning and discussing strategy. One afternoon we were his office, discussing his weekly meeting with our investor. He told me of the struggles and debates in the meeting over our ship date and our budget; over perceived velocity; over staffing and technology requirements. Partway through our discussion, he said that the investor had asked him to produce a line-item budget breakdown.

I jerked upright, startled. Suddenly something was wrong. This request was not in keeping with everything I knew about the relationship between the investor and the president up this point. I reevaluated my assumptions, and nothing fit. Then one assumption change DID fit. I considered it, thought through the range of consequences and they all ended up at the same place. I looked at the president and announced, “You’re going to get fired in the next three months.”

I was right. About 10 weeks later, the president called me in and told me he had been let go.

Two Beautiful Things

Posted by David Brady on September 24, 2010 None comments
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Here are a couple of pages from my journal for today. These are two things I find beautiful, have studied, and can draw… but have only begun to understand.


Click for larger image

The formula on the left is the Y Combinator, derived in Ruby, by Tom Moertel. His writeup and explanation are on raganwald.com. The owl is Aurora, a barn owl who lives and performs daily at Tracy Aviary.

Having time to just noodle around in a journal is something I’ve missed immensely. So great to have time for a life again.