class ActiveRecord::Migration

def copy(destination, sources, options = {})
  copied = []
  schema_migration = options[:schema_migration] || ActiveRecord::SchemaMigration
  FileUtils.mkdir_p(destination) unless File.exist?(destination)
  destination_migrations = ActiveRecord::MigrationContext.new(destination, schema_migration).migrations
  last = destination_migrations.last
  sources.each do |scope, path|
    source_migrations = ActiveRecord::MigrationContext.new(path, schema_migration).migrations
    source_migrations.each do |migration|
      source = File.binread(migration.filename)
      inserted_comment = "# This migration comes from #{scope} (originally #{migration.version})\n"
      magic_comments = +""
      loop do
        # If we have a magic comment in the original migration,
        # insert our comment after the first newline(end of the magic comment line)
        # so the magic keep working.
        # Note that magic comments must be at the first line(except sh-bang).
        source.sub!(/\A(?:#.*\b(?:en)?coding:\s*\S+|#\s*frozen_string_literal:\s*(?:true|false)).*\n/) do |magic_comment|
          magic_comments << magic_comment; ""
        end || break
      end
      if !magic_comments.empty? && source.start_with?("\n")
        magic_comments << "\n"
        source = source[1..-1]
      end
      source = "#{magic_comments}#{inserted_comment}#{source}"
      if duplicate = destination_migrations.detect { |m| m.name == migration.name }
        if options[:on_skip] && duplicate.scope != scope.to_s
          options[:on_skip].call(scope, migration)
        end
        next
      end
      migration.version = next_migration_number(last ? last.version + 1 : 0).to_i
      new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.#{scope}.rb")
      old_path, migration.filename = migration.filename, new_path
      last = migration
      File.binwrite(migration.filename, source)
      copied << migration
      options[:on_copy].call(scope, migration, old_path) if options[:on_copy]
      destination_migrations << migration
    end
  end
  copied
end