message: Optimize collect array of roots
diff: @@ -16,7 +16,12 @@ export default (
  ): ChangedFilesPromise | undefined => {
  if (globalConfig.onlyChanged) {
  const allRootsForAllProjects = configs.reduce<Array<Config.Path>>(
  - (roots, config) => [...roots, ...(config.roots || [])],
  + (roots, config) => {
  + if (config.roots) {
  + roots.push(...config.roots);
  + }
  + return roots;
  + },
  [],
  );
  return getChangedFilesForRoots(allRootsForAllProjects, {
  