dir-tree.js

/* jshint esnext: true */
var fs = require('fs'),
    Emitter = require('events').EventEmitter,
    emitter = new Emitter(),
    eventState = require('event-state'),

    dirTree = function (path, ignoreGlob, cb) {

        var tree = {},
            state,
            callback = [].slice.call(arguments, -1)[0];

        callback = (typeof callback === 'function') ? callback : undefined;

        //TODO: implement igore globbing.
        ignoreGlob = ignoreGlob || 'node_modules';
        return buildBranch(path, tree);


        function buildBranch(path, branch) {
            return new Promise(function (res, rej) {

                fs.readdir(path, function (err, files) {

                    if (err) {
                        //Errors result in a false value in the tree.
                        branch[path] = false;
                        rej(tree);
                    } else {
                        var newEvents = files.map(function (file) {
                            return path + '/' + file;
                        });

                        if (!state) {
                            // If this is the first iteration,
                            // initialize the dynamic state machine (DSM).
                            state = emitter.required(newEvents, function () {
                                // Allow for multiple paradigms vis-a-vis callback and promises.

                                // if a callback was passed, execute it passing it the completed tree.
                                callback && callback(tree);

                                // resolve the promise with the completed tree..
                                res(tree);
                            });
                        } else {
                            // Add events to the DSM for the directory's children
                            state.add(newEvents);
                        }

                        // Check each file descriptor to see if it's a directory.
                        files.forEach(function (file) {
                            var filePath = path + '/' + file;
                            fs.stat(filePath, function (err, stats) {
                                if (err) {
                                    // Errors result in a false value in the tree
                                    branch[file] = false;
                                    emitter.emit(filePath, true);
                                } else if (stats.isDirectory()) {

                                    // Directories are object properties on the tree.
                                    branch[file] = {};

                                    // Recurse into the directory.
                                    buildBranch(filePath, branch[file]);
                                } else {

                                    // If it's not a directory, it's a file.
                                    // Files get a true value in the tree.
                                    branch[file] = true;
                                    emitter.emit(filePath, true);
                                }
                            });
                        });
                    }

                    //Once we've read the directory, we can raise the event for the parent
                    // directory and let it's children take care of themselves.
                    emitter.emit(path, true);
                });
            });
        }
    };

emitter.required = eventState;

module.exports = dirTree;