ID - a unique ID/name generator for JavaScript

ID.js

// Generate unique IDs for use as pseudo-private/protected names.
// Similar in concept to
// <http://wiki.ecmascript.org/doku.php?id=strawman:names>.
//
// The goals of this function are twofold:
// 
// * Provide a way to generate a string guaranteed to be unique when compared
//   to other strings generated by this function.
// * Make the string complex enough that it is highly unlikely to be
//   accidentally duplicated by hand (this is key if you're using `id`
//   as a private/protected name on an object).
function id() {
  // Math.random should be unique because of its seeding algorithm.
  // Convert it to base 36 (numbers + letters), and grab the first 9 characters
  // after the decimal.
  return Math.random().toString(36).substr(2, 9);
};

// Test collisions

function testCollisions(n) {
  let i = 0;
  const list = [];
  while(i++ < n) {
    const guid = id();
    if (list.includes(guid)) {
      throw new Error('Found collision');
    }
    list.push(guid);
  }
}