find method that write by copy and paste.

find_copy_and_paste_method.rb

# USAGE find_copy_and_paste_method.rb MOD_NAME
Rails.application.eager_load!
base_class = ARGV[0].constantize
def all_subclasses(klasses)
  if klasses == []
    klasses
  else
    klasses.map{|k| all_subclasses(k.subclasses) << klasses }.flatten
  end
end

classes = all_subclasses([base_class]).uniq

pry = Pry.new
opts = OpenStruct.new('dconstants?': false, 'instance-methods': true)

all_methods = {}

URL_HELPERS = Rails.application.routes.url_helpers
IGNORE_CLASSES = [Kernel, BasicObject, ActiveSupport, ActionView, ActionDispatch, Object, Tapp, PP].map(&:name).to_set.freeze

classes.each do |klass|
  p klass
  m = Pry::Command::Ls::Methods.new(klass, {}, opts, pry)
  m.send(:all_methods).each_with_object(all_methods) do |method, hash|
    owner = method.owner
    next if IGNORE_CLASSES.include?(owner.name.to_s.split(/::/).first)
    source = begin
               method.source
             rescue Pry::CommandError
               next
             end
    method_name = method.name
    next if method_name.match?(/_(path|url)\Z/)
    hash[method_name] ||= {}
    hash[method_name][owner] ||= []
    hash[method_name][owner] << Digest::SHA1.hexdigest(source.gsub(/\s/, ''))
    hash[method_name][owner].uniq!
  end
end
puts "### find duplicate methdo ###"
all_methods.each do |method_name, classes|
  classes.group_by{|k, v| v }.select{|k, v| v.length > 1 }.each do |hash, duplicate|
    p "##{method_name}: " + duplicate.map(&:first).join(" ")
  end
end