class Middleman::Sources

def did_change(updated_files, removed_files, watcher)
  valid_updated = updated_files.select do |file|
    watcher_for_path(file[:types], file[:relative_path].to_s) == watcher
  end
  valid_removed = removed_files.select do |file|
    watcher_for_path(file[:types], file[:relative_path].to_s).nil?
  end
  return if valid_updated.empty? && valid_removed.empty?
  bump_count
  run_callbacks(@on_change_callbacks, valid_updated, valid_removed)
end