rails--rails/railties/lib/rails/commands/destroy.rb

require 'rails/generators'

#if no argument/-h/--help is passed to rails destroy command, then
#it generates the help associated.
if [nil, "-h", "--help"].include?(ARGV.first)
  Rails::Generators.help 'destroy'
  exit
end

name = ARGV.shift
Rails::Generators.invoke name, ARGV, behavior: :revoke, destination_root: Rails.root