Instrumenting Ruby Methods

Instrumentation is the addition of measurement to code - for example timing how long Ruby is spending in a given method. There are many approaches to adding instrumentation to code in Ruby - whether it’s using 3rd party services like New Relic and Datadog, using libraries like Rubyprof, or even plain old logging. Here I propose an unintrusive Ruby 2.0 technique to add instrumentation to arbitrary methods. If you want to jump straight to the proposed code without the explanation of how or why we got there, here’s your TLDR.