index.js

var fs = require("fs")
var path = require("path")
var node_modules = "node_modules"

function Found() {}

function search(dir, scope) {
  dir = dir || "."
  var context = path.resolve(dir)
  if (!fs.existsSync(context)) return []
  var contents = fs.readdirSync(context)
  return contents.reduce(function (accumulated, name) {
    var relative = path.join(dir, name)
    var isScoped = name.charAt(0) === "@"
    if (isScoped) return accumulated.concat(search(relative, name))
    var found = new Found
    found.name = scope ? scope + "/" + name : name
    found.path = path.resolve(relative)
    if (scope) found.scope = scope
    if (is(relative)) found.link = read(relative)
    accumulated.push(found)
    return accumulated
  }, [])
}

function read(p) {
  return path.resolve(fs.readlinkSync(path.resolve(p)))
}

function pluck(found) {
  return found[this]
}

function root(dir) {
  return path.join(dir || ".", node_modules)
}

function roots(dir) {
  return paths(dir).map(root)
}

function names(dir) {
  return search(root(dir)).filter(is).map(pluck, "name")
}

function paths(dir) {
  return search(root(dir)).filter(is).map(pluck, "path")
}

function links(dir) {
  return search(root(dir)).filter(is).map(pluck, "link")
}

function is(p) {
  if (p instanceof Found) return p.hasOwnProperty("link")
  return fs.existsSync(p) && fs.lstatSync(p).isSymbolicLink()
}

module.exports = {
  links: links,
  names: names,
  paths: paths,
  roots: roots,
  read: read,
  is: is,
  search: search
};