Find unused methods in your ruby (ruby on rails) projects

find_unused_methods_ruby_on_rails.rb

#!/usr/bin/env ruby
skip_methods = %w(new create edit update destroy index show initialize to_s call as_json page per_page build up down change)

output = `grep -hr "^\s*def\s" app/`

methods = output.split("\n")
puts "Found #{methods.size} methods."
unused_methods = []

methods.each_with_index do |line, i|
  puts "\n>> #{i} <<\n" if i % 100 == 0

  line = line.gsub(/\A\s*(.*?)\s*\z/, '\1')
  .gsub(/\(.*/, '')
  .gsub(/def /, '')
  .gsub(/self\./, '')

  next if skip_methods.include?(line)
  next if line[-1] == '='

  print '.'
  if `grep -hr "#{line}" app/`.split("\n").size == 1
    puts "\nCheck up on: #{line}\n"
    unused_methods << line
  end
end