Recursive readdir using highland streams.

highland_readdirp.js

/**
 * This function takes a directory path and returns a flat stream 
 * with stat objects + full file path in the .path property.
 */

var path = require('path');

var h = require('highland');
var readdir = h.wrapCallback(require('fs').readdir);
var stat = h.wrapCallback(require('fs').stat);

/**
 * In this usage example we scan the / directory, 
 * then filter the stream to leave only directories (no files), 
 * then extract only the path property
 * and finally log the resulting items to the console.
 * This code is completely asynchronous.
 */
readdirp('/')
    .filter(function(x) { return x.isDirectory(); })
    .pluck('path')
    .each(h.log);

// implementation
function readdirp(base) {
    return readdir(base)
        .flatten()
        .map(function(x) { return path.join(base, x); })
        .flatMap(function(filepath) {
            return stat(filepath).map(function(x) {
                x.path = filepath;
                return x;
            });
        })
        .map(function(file) {
            if (file.isDirectory()) {
                return [file, readdirp(file.path)];
            } else {
                return [file];
            }
        })
        .flatten();
}