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November 2012

The Simplest Continuous Testing

Here's a simple bash script I use to do things to files whenever they change. It takes a command as an argument and runs that command with the name of a changed file. Many times, it's all I need to do continuous testing.

# Requires that the inotify-tools package be installed.
wait_cmd="inotifywait -m -r --format %w%f -e modify ."
$wait_cmd | grep --line-buffered $filter | while read file; do 
  $cmd $file

There's No Such Thing As Software Productivity

Bill Caputo, through repeated conversations we've had, has convinced me of something very surprising. It was something that changed the way I think about the world, and how I do my job.

There is no such thing as software productivity.

As Martin Fowler observed almost a decade ago, productivity in software cannot be usefully measured. The reason why is it just doesn't exist in The Realm of Relevant Things. Put another way, productivity has no applicability as a metric in software. "How much did we create today?" is not a relevant question to ask. Even if it could be measured, productivity in software does not approximate business value in any meaningful way.

This is because software development is not an activity that necessarily produces anything. Here's a thought experiment: Let's say that you have a couple of developers working on the same project, and by accident, both of them pick up the same task on the same day. The first one, Frank, hauls off and writes a 1000 line framework that solves the problem beautifully. The code is well written, well tested, and the deployment and operation of it is well documented. The second developer, Peter, heads off to to the park for the day, where he thinks about the problem while he feeds the pigeons. Around 4:45, Peter wanders back to the office, deletes 100 lines of code, deploys the change...and the problem is fixed.

Which of these two developers was more "productive" today? The answer is: It doesn't matter. What matters the that Peter solved the problem, while simultaneously reducing long term maintenance costs for the team. Frank also solved the problem, but he increased maintenance costs by producing code, and so (all other things being equal) his solution is inferior. To call Peter more "productive" is to torture the metaphor beyond any possible point of utility.

I would argue that what good software developers do is remove problems. The opposite, in fact, of production. The creation of technological artifacts such as code, documentation, data, etc...are all necessary evils to achieve the goal of removing problems. That's why, sometimes, the most effective solution to a problem is a 5 minute conversation.

This post has been truncated. Everything after this paragraph was a rant, and not relevant to the central point. Kind of ironic, right? Thanks for reading!