index.js

/*eslint-env node*/

"use strict";

var findGlobalPackages = require("find-global-packages");
var path = require("path");
var EventEmitter = require("events").EventEmitter;
var eventEmitter = module.exports = new EventEmitter();

// make sure /usr/local/bin is in env.PATH on Mac
if (process.platform === "darwin") {
  var envPaths = process.env.PATH.split(path.delimiter);
  if (envPaths.indexOf("/usr/local/bin") === -1) {
    envPaths.push("/usr/local/bin");
  }
  process.env.PATH = envPaths.join(path.delimiter);
}

function uniq(arr) {
  return arr.reduce(function (result, item) {
    if (result.indexOf(item) === -1) {
      result.push(item);
    }
    return result;
  }, []);
}

findGlobalPackages(function(err, dirs) {
  if (err) {
    if (eventEmitter.listeners("error").length > 0) {
      eventEmitter.emit("error", err);
    } else {
      console.error(err.stack ? err.stack : err.toString());
    }
    return;
  }
  // get all currently defined NODE_PATHs
  var nodePaths = process.env.NODE_PATH ? process.env.NODE_PATH.split(path.delimiter) : [];
  // globalNodePaths will be a list of strings representing paths to globally available node_modules directories
  var globalNodePaths = uniq(dirs.map(function (dir) {
    return path.resolve(dir, "..");
  }));
  // merge them together
  nodePaths = uniq(nodePaths.concat(globalNodePaths));
  // expose them back to NODE_PATH env var
  process.env.NODE_PATH = nodePaths.join(path.delimiter);
  // refresh paths for node
  require("module").Module._initPaths();
  // emit the ready event in case someone needs it
  eventEmitter.emit("ready", globalNodePaths);
});