build utils for node. taken from http://stackoverflow.com/questions/5827612/node-js-fs-readdir-recursive-directory-search

build-utils.js

/*
Usage:

var compile = require('build-utils').compile;

compile('less-src', 'public/css', function(lessFile, destFile) {
  var cssFile = destFile.substr(0, destFile.indexOf('.less')) + '.css';
  run('./node_module/.bin/lessc' + lessFile + ' > ' + cssFile);
});
*/

var fs = require('fs');

var walk = function(dir, done) {
   var results = [];
   fs.readdir(dir, function(err, list) {
      if (err) {
         return done(err);
      }

      var pending = list.length;
      if (!pending) {
         return done(null, results);
      }

      list.forEach(function(file) {
         file = dir + '/' + file;
         fs.stat(file, function(err, stat) {
            if (stat && stat.isDirectory()) {
               walk(file, function(err, res) {
                  results = results.concat(res);
                  if (!--pending) {
                     done(null, results);
                  }
               });
            } else {
               if (file.indexOf('.swp') == -1) {
                 results.push(file);
               }
               
               if (!--pending) done(null, results);
            }
         });
      });
   });
};

var compile = function(srcDir, destDir, callback) {
   walk(srcDir, function(_, files) {
      files.forEach(function (srcFile) {
         var destFile = destDir + (srcFile.substr(srcDir.length, srcFile.length));
         callback(srcFile, destFile);
      });
   });
};

module.exports = { compile: compile, walk: walk };