Finding The Source of Ruby Methods

Ruby's Method class includes a feature that can help you quickly find the location of source code files where a particular method is defined. The method is aptly named source_location.

When debugging a project that is using the Treat gem, you can take a source dive by first finding the relevant source files. For instance, if you want to look into the word creation functionality, you might go through an exploratory process like the following:

> require 'Treat'
=> true
> Treat::Entities::Word.build('stuff')
=> Word (70331843958460)  --- "stuff"  ---  {}   --- []
> Treat::Entities::Word.method(:build)
=> #<Method: Class(Treat::Entities::Entity::Buildable)#build>
> Treat::Entities::Word.method(:build).source_location
=> ["/Users/jbranchaud/.gem/ruby/2.1.4/gems/treat-2.1.0/lib/treat/entities/entity/buildable.rb", 29]

You can now take a closer look at the implementation of the build method.

The main caveat to this process is that it can only find source locations for methods defined in ruby land. Calling source_location on any method defined in C code will result in nil.