Check if a module has been included in a class in ruby

When programming in ruby you may have to reach for a module that has encapsulated some helper functions that you want to use in your class. To tell if the module has been included in your class you can use the Module classes include method. Likewise, to tell if you choose to extend the module you can check that through the extend method.

Below is a working example. Notice we do not need to instantiate our classes to invoke these methods:

module SomeModule
  def self.included(base)
    p base.inspect
  end

  def self.extended(base)
    p base.inspect
  end
end

class IncludedClass
  include SomeModule
end

class ExtendedClass
  extend SomeModule
end

Running this script will print:

"IncludedClass"
"ExtendedClass"

To fill your hearts desire for more ruby programming blog posts check out this one.