Bikes and Code

So you know a handful of programming languages and now need to learn another one? Interesting.

One of the most important things when learning a new programming language is to have a couple of small programs in mind that you can implement. You don’t learn a language by reading about it, though that helps significantly. Also, you don’t learn a language by reading code, though once you have a handle on the syntax and semantics, this is invaluable to improving. You learn a language by writing code in it, running the code and debugging the code.

You don’t jump into a new language and write a dependency injection framework or build VisagePamphlet, the new killer social media application. You need to write a few small programs that you can personally validate are more or less correct with a test suite or simple manual execution.

The choice of what to write is kind of tricky, so here is what you should do :

Implement a Brainfuck Interpreter

WHAT.

If you have never attempted this, it might seem kind of insane, but it’s actually far less difficult than you may imagine. The language is so tiny that a reasonable implementation in any current mainstream language is going to be under 100 lines of code. But more importantly, this little program you are going to write requires:

• variables
• loops
• if/else
• switches
• possibly recursion
• thinking about types (if applicable)
• string manipulation
• IO

But this has an additional side benefit as well, you have to write Brainfuck programs to exercise and test out your new interpreter. This in and of itself is a challenge due to the limited features available in the language. In addition, once your test programs are working, there are a host of programs available on the Internet which you can download and throw at your interpreter.

Finally, depending on how deep you wish to go, this program is now an excellent launchpad for future experimentations into the language you wish to learn. Write something so you can dump the memory of the Brainfuck program. Add another pass to verify the program is valid before running it.

A few days ago, Translink announced that they would be releasing their bus, train and seabus route information in a standard format. A list of every bus stop, route, time, etc might not seem overly exciting to most people, but I love datasets. Admittedly, I often don’t know exactly what to do with datasets, but that’s hardly the real issue here. Anyhow, this seemed like a promising thing for me to do and I downloaded it, unzipped it and spent a couple of hours prepping a Rails project to serve as a new home for it.

Roughly 500 routes, 8700 stops, 126000 trips and 3.4 million timepoints at those stops. Not a whopping amount of data, but enough to start having some fun. My initial plan was just to be able to plot the stops for a given route onto google maps. That’s done in it’s ugly glory at my stopfinder. If you want to search for a 1 or 2 digit route, put in the leading 0′s. Sorry, haven’t done that yet.

My next steps are going to be to publish a number of primitive operations on the data with results in JSON format. Things like ‘closest stop to lat,lon’, ‘how to get from stop x to stop y’, and other similar sorts of things. The idea being that if I can build up a suitable library of common operations on the dataset, any future ideas that do come to mind should be relatively easy to implement.

That and if anyone does want to do some data mining, well, this is an option. I’ll post any updates, formats and that sort of thing on this site as I work through it. In general, the services will be pretty much simply URL based and will return raw JSON. Nothing special, but fairly easy to parse and work with. I have a relatively irrational dislike of XML which I will probably get over at some point, but it will take someone making a very good argument.

Uh, yeah.

So it is, but actually stating that, or anything along those lines? Way to kill the team, boss! (See Peopleware)

That said, quality assurance, quality control, QA, call it what you want, but it’s one of the more misunderstood aspects to software development. Oh sure, everyone knows that they need to do more QA or better QA, but lip service is about all that is ever paid towards it. I am notably not including in my ‘everyone’ those who feel that QA can be completely automated. You guys are wrong and I’m going to leave it at that. You also may think you don’t need to do it, see this article for some classic arguments against that fallacy.

I’m not going to go into depth about QA, how to do it, best practices or anything along those lines as I’m fairly unqualified. That said, I’m not really qualified to talk about anything, but that doesn’t really stop me.

QA is a processes, not a task

This particular fail case is something I’ve seen in multiple organizations now. The most obvious symptom of this is when management has decreed that there is a block of a few hours set aside to ‘do QA’ on an application with a few hundred known use cases. Another obvious indicator is when other employees are volunteered to do a few hours of QA on top of their normal job. Think you’re going to get good results from that?

The root cause of this failure is simply not understanding how QA works, so let’s walk through it a bit. In a very broad sense, the general list of tasks for QA is something like this:

1. Go through the basic cases

2. Go through the corner cases

3. Go through obscure, known failure cases

4. Exploratory testing

5. Automating 1, 2 and 3.

So, how does this fit into a day of work? Let’s find out:

First off, we’re going to go through the basic use cases for the application. Then, there is a pile of corner cases that are pretty valid that need to be checked out. Then it’s time to check all the really obscure, but horribly embarrassing failures that have been seen before. From there we can finally…What? You changed the code? Okay, first off, we’re going to go through the basic use cases for the application…

Interruption here! “Silly tester,” says the savvy developer, “You only need to re-test the parts of the system that were changed.” Nice theory, but wrong in many, many ways. Simply put, if this was the case, testing outside of developers would never be needed. That generally goes well.

Back to the task at hand, do the basic cases, do the corner caWHAT? Changed again? Basic cases…

The real job of QA starts at step 4, which we haven’t even seen yet. Exploratory testing is finding the embarrassing defects before they get out into the wild. A good tester at this phase is going to break your application in ways you haven’t even dreamed of. In ways that only 0.1% of your users would ever try to do. Of course, if 0.1% of your users do it, and you get 10k uniques per day? That’s 10 people per day that are going to hit this embarrassing bug that how could you possible let into the wild and I’m taking my business elsewhere right now as I obviously cannot trust you with my data. And if one of those has a blog? Heh. Have fun with that.

So the epic fail with having 16 hours scheduled in to test your quarter million lines of code application? If you’ve got bug fixing going on at the same time, any of your competent testers will never get past step 1. Any testers that listen to the savvy developer, or worse, are the savvy developer will miss basic cases and you deploy with fundamental breaks.

The purpose of QA is not to have someone say, “Wonderful developer, your application is perfect!” If I hear that from a tester, I assume the person isn’t doing their job very well. QA should hurt your feelings. Assumptions you made should be laid bare and justified or thrown out if incorrect. This is often the last line of defense before your customers see your application, take it seriously.