Remove unused rvm gemsets

gem_cleaner.rb

# Safely cleans up your rvm Gemsets with the following:
# - Deletes gemsets associated with older rubies than the latest (if more than one)
# - Runs `bundle clean` to remove unused gems in latest gemsets
# - Removes rubies (and related gemsets) that are no longer used by a gemset
gemsets = Dir["#{ENV['HOME']}/.rvm/gems/*"].select do |folder|
  folder.include?("@")
end

gemsets = gemsets.map do |folder|
  File.basename(folder)
end

gemsets = gemsets.group_by do |folder|
  folder.split("@").last
end

rubies = []

gemsets.each do |name, gemsets|
  next if name == "global"
  sets = gemsets.sort

  keep = sets.pop

  # Remove any gemsets that are bound to older versions of ruby than the latest
  sets.each do |gemset|
    (ruby, set) = gemset.split("@")
    `rvm use #{ruby} do rvm --force gemset delete #{set}`
  end

  # Clean up unused gems in the gemset we're keeping
  `rvm #{keep} do bundle clean --force`

  rubies << keep.split("@").first
end

# Remove rubies (and gemsets) that we no longer need
gemsets["global"].each do |gemset|
  (ruby, set) = gemset.split("@")
  next if rubies.include?(ruby)

  `rvm remove #{ruby}`
end