passing through files doing whatever

filer.js

var fs = require('fs');
var pathModule = require('path');
var Q = require('q');
var replace = require('replace');

function init(path, refactorFiles, destPath) {
  // console.log(path);
  findPattern(path, /language\.js$/).then(function (filesPaths) {
    refactorFiles(filesPaths, destPath);
  }).catch(console.log);
}

function findPattern(path, pattern) {
  return Q.nfcall(fs.stat, path).then(function (stat) {
    if (stat.isFile() && pattern.test(path)) {
      return path;
    }else if(stat.isDirectory()) {
      return Q.nfcall(fs.readdir, path).then(function (files) {
        var promises = files.map(function (file) {
          return findPattern(pathModule.join(path, file), pattern);
        });
        return Q.allSettled(promises).then(function (results) {
          return results.filter(function (result) {
            if (result.state==='fulfilled'){
              return true;
            }else{
              console.log('Error:',result.reason);
              return false;
            }
          }).map(function (result) {
            return result.value;
          }).filter(function (result) {
            return result!==undefined;
          });
        }).then(function (results) {
          return results.reduce(function (result, curr) {
            if(Array.isArray(curr)){
              return result.concat(curr);
            }

            result.push(curr);
            return result;
          }, []);
        });
      });
    }
  });
}

function refactorFiles(filesPaths, destPath) {
  filesPaths.forEach(function(filePath) {
    if (destPath){
      var result = /\\([^\\\.]+)\.module/.exec(filePath);
      if (result && result[1]){
        var fileName = result[1] + '.js';
        var fileDestPath = pathModule.join(destPath, fileName);
        fs.createReadStream(filePath).pipe(fs.createWriteStream(fileDestPath)).on('close',function () {
          console.log('done with', fileDestPath);
          replace({
            regex:/mod.translation\(\s?(\'|\")en(\'|\")\s?\,/,
            replacement:'module.exports=(',
            paths: [fileDestPath],
            recursive: false,
            silent: true,
          });
        });
      }
    }else {
      console.log(filePath);
    }
  });
}

init(process.argv[2], refactorFiles, process.argv[3]);