srp-violator.rb

class SRPViolationError < StandardError
  def initialize(klass)
    @klass = klass
  end

  def message
    "Class #{@klass} surely does something AND detects SRP violation, right? Well, your class should do only one thing! :D"
  end
end

module SRPViolationMixin
  def self.included(base)
    raise SRPViolationError.new(base)
  end
end

class Object
  def acts_as_srp_violation
    include SRPViolationMixin
  end
end

class MyCleanClass
  acts_as_srp_violation

  def go
    puts 'Go!'
  end
end