Directory tree walker & js file resolver

resolver.js

var fs      = require("fs");
var path    = require("path");
var util    = require('util');

function Resolver(pathToDirectory) {
    this.mappings = dirTree("initial-value", pathToDirectory).contents;
    //console.log("[URL Resolver] Discovered mappings: %s", util.inspect(this.mappings, false, null));
}

function dirTree(name, filepath) {
    var result = { name: name };

    if (fs.lstatSync(filepath).isDirectory()) {
        result.contents = {};

        fs.readdirSync(filepath)
        //-- now it's a list of strings, e.g. ["routes","a.js"] --
        .map(function(child) {
            return dirTree(child, filepath + '/' + child);
        })
        //-- now it's an array of objects, e.g. [ {name:"routes",contents: {}}, {name:"a.js",contents:fn()} ] --
        .reduce(function(acc, curr) {
            // from an array item to the accumulator object
            result.contents[curr.name] = curr.contents; //-- reduce to: { name: contents } --
        }, {});
        //-- now it's reduced to { routes: {}, "a.js": fn() } --
    } else if (/^[^_].*.js$/.test(filepath)) {
        //-- is a *.js file whose name is not beginning with underscore --
        result.contents = require(filepath);
    }

    return result;
}

module.exports = Resolver;