Script to check & commit all stable auto-corrections of Rubocop

rubocop_stable_auto_correct.rb

require 'fileutils'
# TODO get list of Cops that support auto-correct
# for each cop, run the following
# only commit if change was stable
# (each run takes ~2 minutes)
prefix = ARGV[0]
files = Dir["#{prefix}/**/*.rb"].sort
orig = Hash[files.map do |file|
    FileUtils.cp(file, "#{file}.orig")
    [file, %x(ruby --dump insns #{file}).gsub(/\s+\(\s*\d+\)$/, '')]
end]
%x(bundle exec rubocop --auto-correct #{prefix})
changed = Hash[files.map { |file| [file, %x(ruby --dump insns #{file}).gsub(/\s+\(\s*\d+\)$/, '')] }]

files.each do |file|
  stable = (orig[file] == changed[file])
  puts stable, file unless stable
  File.open("#{file}-orig.txt", 'w') { |f| f.write(orig[file]) }
  File.open("#{file}-changed.txt", 'w') { |f| f.write(changed[file]) }
end