redo

redo.rb

namespace :db do
  desc "Redo target timestamp newer migration."                                                                                                                                                                                                                                                                             
  task :redo_timestamp => :environment do
    timestamp = ENV['TIMESTAMP']
    files = Dir.glob("db/migrate/*.rb").map {|file|
      md = file.split(File::SEPARATOR).last.match(/(^\d+)_\w+\.rb/)
      [md[0], md[1].to_i]
    }.select{|match| match[1] > timestamp.to_i }.map{|match| match[0]}
    ENV['STEP'] = files.size.to_s
    Rake::Task['db:migrate:redo'].invoke
  end
end