Open Delivered Emails in Dev Email Client (Mac-only)

#!/usr/bin/env ruby
require 'listen'

# This script watches for ActionMailer mail delivered to tmp/mails in dev,
# adds a timestamp and proper extension to the filename, and opens in the
# default client (Mac-only).

APP_ROOT = File.expand_path('..', __dir__)

listener = Listen.to("#{APP_ROOT}/tmp/mails") do |_modified, added, _removed|
  added.each do |added_file|
    if added_file.end_with?(".eml")
      system("open -a Mail #{added_file}")
    else
      File.rename(added_file, "#{added_file}-#{Time.now.to_i}.eml")
    end
  end
end

listener.start
sleep