NodeJS concatenate all files in a directory

Is there a faster or more succinct way to concatenate all of the files located in a directory using NodeJS? In bash I could do something like this: ``` for file in $1 do cat "$file" echo done > $2; ``` Here is what I'm doing now: ``` var fs = require('fs'); var Promise = require('bluebird'); module.exports = function(directory, destination) { return new Promise((resolve, reject) => { fs.readdir(directory, (err, files) => { if (err) { return reject(err); } (function next() { var file = files.shift(); if (!file) { return resolve(); } fs.readFile(directory + '/' + file, (err, content) => { if (err) { return reject(err); } fs.appendFile(destination, '\n' + content, (err) => { if (err) { return reject(err); } return next(); }); }); })(); }); }); }; ```