Upgrade Rails 4 to Rails 5

upgrade_rails.rb

#! /usr/bin/env ruby

filenames = Dir["app/models/*.rb"]
filenames.each do |file_name|
  next if file_name.include? 'application_record.rb'
  text = File.read(file_name)
  new_contents = text.gsub(/< ActiveRecord::Base/, "< ApplicationRecord")
  if text != new_contents
    p "changing #{file_name}"
    # To merely print the contents of the file, use:
    # puts new_contents
    File.open(file_name, "w") {|file| file.puts new_contents }
  end
end

filenames = Dir["app/controllers/**/*.rb"]
filenames.each do |file_name|
  text = File.read(file_name)
  new_contents = text.gsub(/before_filter/, "before_action")

  if text != new_contents
    p "changing #{file_name}"
    # To merely print the contents of the file, use:
    # puts new_contents
    File.open(file_name, "w") {|file| file.puts new_contents }
  end
end